@article {pmid41193734,
year = {2025},
author = {Mathpal, S and Panickar, A and Joshi, T and Ramaiah, S and Anbarasu, A},
title = {Genomic surveillance of vancomycin-resistant Enterococcus faecium: a study on Resistome, Plasmidome, and mobilome profiling.},
journal = {Current genetics},
volume = {71},
number = {1},
pages = {26},
pmid = {41193734},
issn = {1432-0983},
support = {IRIS ID: 2021-11889; AMR/Adhoc/290/2022-ECD-II//Indian Council of Medical Research/ ; },
abstract = {Vancomycin-resistant enterococci (VRE) are critical nosocomial pathogens, classified as high priority by the World Health Organization (WHO) due to rising antibiotic resistance. Among these, Vancomycin-resistant Enterococcus faecium (VREfm) presents a significant clinical challenge, frequently detected in healthcare-associated infections and exhibiting resistance to multiple antibiotics. This study presents a genomic surveillance analysis of 63 Enterococcus faecium (E. faecium) isolates obtained from the public database from India during the period January 2017 to December 2021. These isolates were confirmed as VREfm, making them valuable for understanding the key resistance genes and mutations commonly associated with strains. Genomic analysis revealed diverse plasmid replicons such as pRE25, pRUM, and pIP501, often coexisting in single isolates, indicating active horizontal gene transfer. Multiple antimicrobial resistance genes, such as vanHAX, ermB, optrA, and blaOXA-232, were identified along with insertion sequences (IS3, ISL3, IS256), integrons, and transposons (Tn1546, Tn917). Mutations in GyrA, ParC, and PBP5 proteins associated with fluoroquinolone and β-lactam antibiotics were also detected in each isolate. Amino acid substitutions associated with daptomycin resistance were identified in the encoded proteins of the liaR (LiaR-W73C), liaS (LiaS-T120A), cls (Cls-T298S), and rpoB (RpoB-S491F) genes. Three novel deleterious amino acid substitutions were also observed in Cls-R424S, RpoB-M475V, and RpoC-T634K, encoded by the cls, rpoB, and rpoC genes, respectively, that may impact protein function. Overall, this genomic survey provides a framework for hypothesis-driven studies exploring resistance evolution and gene mobility in E. faecium.},
}

@article {pmid41528640,
year = {2026},
author = {Deb, S and Kumari, L and Singh, UB},
title = {Comparative population genomic analysis of Brevibacterium casei isolated from a tuberculosis patient.},
journal = {Folia microbiologica},
volume = {},
number = {},
pages = {},
pmid = {41528640},
issn = {1874-9356},
support = {All-India Institute of Medical Sciences//All-India Institute of Medical Sciences/ ; },
abstract = {Brevibacterium casei, previously considered as non-pathogenic to human host is now drawing attention due to its association with frequent infections in immunocompromised patients suffering from leukemia and HIV. Despite growing incidence of B. casei infections, limited number of genomes have been sequenced to date, this restricts our understanding on ge-nomic heterogeneity and the evolution of pathogenic B.casei strains. Here, we sequenced the whole genome of B. casei HOS 100 strain isolated from a tuberculosis patient. The genome size was 3.8 Mb and G + C content 67.94%. Present study estimates the genetic diversity and factors effecting evolutionary dynamics of B. casei strains. Phylogenomic and population genomic analyses reveal that recombination, horizontal gene transfer, and the ongoing expansion of the pangenome contribute to the genetic diversity and potential emergence of genetically distinct B. casei strains.},
}

@article {pmid41832407,
year = {2026},
author = {Gündoğdu, HB and Rakıcı, E and Ejder, N and Çopur Çiçek, A and Özgümüş, OB},
title = {Genotypic and phenotypic landscape of carbapenem-resistant Pseudomonas aeruginosa isolated from respiratory and non-respiratory samples in a tertiary hospital.},
journal = {BMC microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1186/s12866-026-04756-8},
pmid = {41832407},
issn = {1471-2180},
abstract = {BACKGROUND: The World Health Organization lists carbapenem-resistant Pseudomonas aeruginosa (CRPA) as a critical priority pathogen. However, the links between resistance phenotypes, virulence factors, and clonal spread remain incompletely understood. We aimed to characterize the genotypic and phenotypic landscape of clinical CRPA isolates and evaluate whether specimen source or type III secretion effectors (exoT/exoY) serve as predictors of antibiotic resistance. METHODS: Fifty-eight consecutive CRPA isolates from respiratory and non-respiratory specimens were analyzed. Susceptibility to 10 antimicrobial agents was determined using an automated system. PCR was used to screen for seven carbapenemase genes, six virulence/quorum-sensing genes, and the efflux marker mexY. Macrorestriction patterns were typed by SpeI-PFGE. Statistical associations were assessed using two-tailed Fisher’s exact tests with Benjamini–Hochberg false-discovery-rate (FDR) correction (α = 0.05). RESULTS: Resistance rates were highest for piperacillin/tazobactam (91%), ceftazidime (81%), and cefepime (81%); notably, 34% of isolates exhibited a pan-drug-resistant (PDR) profile. Only three isolates (5%) carried blaVIM; no other carbapenemase genes were detected. Virulence markers were highly prevalent (exoY 66%, exoT 57%, algD 45%; lasR 91%, rhlR 95%). After FDR adjustment, neither virulence gene presence (exoT, exoY) nor specimen origin correlated significantly with resistance to β-lactams, aminoglycosides, or fluoroquinolones (lowest q = 0.093). Furthermore, gene prevalence did not differ significantly between respiratory and non-respiratory isolates. PFGE analysis revealed 41 distinct pulsotypes without a dominant clone, suggesting sporadic horizontal gene transfer rather than clonal expansion. CONCLUSIONS: This CRPA cohort is genetically diverse, multidrug-resistant, and lacks anatomical segregation by genotype. The presence of exoT/exoY does not appear to shape resistance phenotypes in this setting. Infection control strategies should prioritize the containment of mobile genetic elements and implement genome-based surveillance, rather than focusing solely on specific clones or infection sites.},
}

@article {pmid41872433,
year = {2026},
author = {Akter, T and Islam, S and Haider, AM and Fatema, K and Stapleton, F and Willcox, M},
title = {Antibiotic resistance mechanisms and global resistance patterns of Pseudomonas aeruginosa in microbial keratitis.},
journal = {European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology},
volume = {},
number = {},
pages = {},
pmid = {41872433},
issn = {1435-4373},
abstract = {BACKGROUND: Microbial keratitis (MK) is a rapid and devastating infection that can result reduced vision, with lack of treatment potentially resulting in stromal necrosis and even permanent vision loss. Pseudomonas aeruginosa is a common cause of MK and its rise in antibiotic resistance has made it increasingly difficult to treat. PURPOSE: This review aims to provide a better understanding of the resistance mechanisms of P. aeruginosa and highlights major adaptations to combat fluoroquinolones, aminoglycosides, β-lactams and polymyxin antibiotics commonly used in MK, and addresses the global resistance profiles of P. aeruginosa keratitis. METHOD: A narrative review was conducted using PubMed, Scopus, Web of Science, MEDLINE, and Google Scholar. Search terms included “Pseudomonas aeruginosa”, “microbial keratitis”, “antibiotic resistance”, antibiotic class-specific resistance terms, “surveillance studies”, and “regional resistance patterns” to consolidate current information of the various intrinsic, acquired and adaptive resistance mechanisms of P. aeruginosa conferred across fluoroquinolones, aminoglycosides, β-lactams and polymyxin along with resistance profile of keratitis isolates across continents. RESULTS: P. aeruginosa displays complex resistance mechanisms, including intrinsic efflux systems, reduced porin permeability, enzymatic drug inactivation, horizontal gene transfer, and target-site mutations, contributing to MDR in MK. Resistance patterns vary markedly by region, with higher resistance to fluoroquinolones, cephalosporins, and aminoglycosides reported in Asia, while Europe and North America showed lower rates. Australian isolates demonstrate heterogeneous resistance, retaining susceptibility to aminoglycosides. CONCLUSION: Future studies comparing resistance mechanisms and data of P. aeruginosa across regions will be essential to identify geographical variations, inform region-specific surveillance, guide targeted therapies to improve interventions of MK.},
}

@article {pmid41961078,
year = {2026},
author = {Nagaraja, PK and Mitra, SD and Murugesan, D and Muninarayanaswamy, PKA and Geddam, S and Venugopal, N and Tewari, R and Nayakvadi, S and Shome, BR and Shome, R},
title = {Genomic Insights into Mammaliicoccus sciuri from Subclinical Bovine Mastitis to Unveil Key Resistance, Virulence, Biofilm and Adaptation Traits.},
journal = {Current microbiology},
volume = {83},
number = {6},
pages = {},
pmid = {41961078},
issn = {1432-0991},
support = {IXX14760//All India Indian Network for Fisheries and Animal Antimicrobial Resistance (INFAAR) funded by Indian Council of Agricultural Research, Ministry of Agriculture and Framers Welfare, Govt. of India, New Delhi/ ; },
abstract = {The Mammaliicoccus sciuri (M. sciuri), is recognized as a reservoir of antimicrobial resistance (AMR) genes, poses challenges in the Indian dairy sector where antibiotic use is poorly regulated. This study aimed to genomically characterize M. sciuri (formerly Staphylococcus sciuri) isolates recovered from subclinical mastitis (SCM) cattle milk. A total of 128 composite (quarter-wise pooled) milk samples were collected from 199 households (HH) across 16 epiunits /villages in four blocks of Chikkaballapur district, Karnataka, India. Of these, 36 milk samples (28.13%, 36/128; 95% CI: 21.06–36.46%) were diagnosed with SCM using the California Mastitis Test (CMT) and bacteriological culture yielded 113 isolates (88.28%; 113/128; 95% CI: 81.56–92.77%) were phenotypically identified as Staph spp. Through molecular technique PCR targeting the gap gene, two isolates (1.77%; 2/113; 95% CI: 0.49–6.22%) from Hosuru and Gattamaranahalli epiunits were confirmed as M. sciuri and both isolates were mecA-positives indicating methicillin resistance. Whole genome sequencing (WGS) identified 36–37 resistance genes (mecA and blaZ), conferring resistance to β-lactams, macrolides, fluoroquinolones and aminoglycosides. Horizontal gene transfer (HGT) was evidenced by diverse mobile genetic elements (MGEs) such as SCCmec variants, insertion sequences, transposons (IS3, IS6, IS256, and IS1182) and plasmids (Rep1, Rep13, RepUS5 and RepUS43). Virulence profiling uncovered biofilm-associated genes (ica, bap) and heavy metal resistance operons (ars, cop, znu) suggesting mechanisms for environmental persistence and co-selection of resistance traits. Phylogenetic analysis of 99 global isolates revealed host-and geography-specific clustering with Indian isolates occupying distinct evolutionary niches. These findings highlights its possible role as an AMR reservoir and also in bovine mastitis.},
}

@article {pmid42056649,
year = {2026},
author = {Al-Khalidi, MSH and Yetiman, AE and Akbulut, M and Sağıroğlu, P},
title = {Comparative pathogenomics and in silico analysis of energy metabolism in Acinetobacter baumannii ST195 and novel Turkish isolates encoding blaOXA-23, blaOXA-66, and blaOXA-852.},
journal = {International microbiology : the official journal of the Spanish Society for Microbiology},
volume = {},
number = {},
pages = {},
pmid = {42056649},
issn = {1618-1905},
abstract = {Acinetobacter baumannii is a significant hospital-acquired pathogen recognized for its antibiotic resistance and environmental durability. The present study investigates the genomic and metabolic characteristics of Turkish A. baumannii isolates (ST195 and novel sequence type) using whole-genome sequencing, comparative pathogenomics, and phenotypic assays. Genomic analyses demonstrated significant horizontal gene transfer, phage integration (Salmon_SSU5, Acinet_Bphi_B1251), and genomic islands enriched with resistance and virulence genes. ST195 (T3) exhibited meropenem susceptibility (MIC ≤ 0.125 µg/mL) despite harboring blaOXA-23, linked to adeN efflux regulator loss. In contrast, colistin resistance in T3 was correlated with putative lpxA/C/D mutations causing LPS deficiency. Virulence profiling identified conserved systems for adherence (OmpA), biofilm formation (bap, csuABCDE), and iron acquisition (acinetobactin), while capsule heterogeneity appeared to affect immune evasion. Metabolic reconstruction highlighted nitrogen and sulfur assimilation, as well as ethanol catabolism, which facilitate survival under host stress. Resistome analysis linked blaOXA-852, adeFGH, and armA to resistance against carbapenems and aminoglycosides, while transposase-mediated frameshift mutations accounted for amikacin susceptibility in T3 despite the presence of APH(3’)-VIa. The open pangenome (6,402 genes, 41.9% core) reflected adaptive genomic plasticity. This study highlights the importance of genomic diversity, metabolic flexibility, and regulatory mutations in influencing A. baumannii resistance and virulence. It also identifies potential metabolic and virulence-related features that may guide future therapeutic and anti-virulence strategies.},
}

@article {pmid42335767,
year = {2026},
author = {Li, T and Guo, T and Cui, M and Cao, Y and Zhi, Z and Wang, P and Li, Q and Zhang, J},
title = {Rearing systems shape the successional dynamics of the gut microbiota, resistome, and mobilome in Lueyang Black-boned chickens.},
journal = {Poultry science},
volume = {105},
number = {10},
pages = {107322},
doi = {10.1016/j.psj.2026.107322},
pmid = {42335767},
issn = {1525-3171},
abstract = {Understanding the ecological factors shaping antimicrobial resistance (AMR) dissemination in agricultural environments is critical for global "One Health". Here, we performed metagenomic sequencing to investigate the impact of intensive cage-reared (CR) and free-range (FR) systems on the gut microbiota, resistome, and mobilome dynamics of Lueyang Black-boned chickens across different production stages. Our analyses revealed that distinct rearing systems drove resistome alterations by reshaping microbial community assembly and horizontal gene transfer (HGT) pathways. Specifically, the CR system imposed strong deterministic stress, thereby enriching opportunistic taxa (such as Desulfovibrio) and promoting a highly connected but topologically fragile microbial network. Conversely, the FR system exhibited a higher total abundance of commensal resistance genes, a process mainly driven by diverse transposon-mediated integrations including tnpA and ISBf10. In contrast, the CR system was associated with high-risk, clinically relevant resistance determinants. These included extended-spectrum beta-lactamases and multidrug resistance cassettes. Targeted network tracking unmasked highly divergent potential host-vector-ARG associations. Resistance expansion under confined CR conditions showed strong vector-dependency, being fundamentally linked to the broad-host-range plasmid IncQ1 alongside clinically relevant mobilization elements, including Class 1 integrons. Longitudinally, the FR resistome achieved ecological stabilization. In contrast, the CR microbiota exhibited continued genetic flux, continuously acquiring transient resistance elements during the observed production period. These findings demonstrate that welfare-friendly rearing management serves as a critical ecological intervention to limit the proliferation of mobile, high-risk resistance traits. Ultimately, future agricultural surveillance must transition beyond quantifying total resistance gene abundance to prioritize functional risk assessments and mobilization potential.},
}

@article {pmid42335810,
year = {2026},
author = {Cao, M and Gao, Z and Gai, N and Russel, M and Ma, S and Xu, D and Wang, F and Tao, Y and Sun, K and Wang, F},
title = {Polystyrene nanoparticles and phosphorus sources jointly modulate antibiotic resistance gene enrichment in microalgae-bacteria systems.},
journal = {Journal of hazardous materials},
volume = {514},
number = {},
pages = {142791},
doi = {10.1016/j.jhazmat.2026.142791},
pmid = {42335810},
issn = {1873-3336},
abstract = {The regulatory mechanisms of antibiotic resistance genes (ARGs) in freshwater microalgae-bacteria systems under combined nutrient-nanoplastic stress remain poorly understood. Herein, we investigated the combined effects of phosphorus (P) sources (inorganic phosphate (IP), adenosine monophosphate (AMP), and phytic acid (PA)) and polystyrene nanoplastics (PS-NPs; 10 and 100 mg/L) on the Chlorella pyrenoidosa‑bacteria system. Results showed that P utilization efficiency followed the order IP > AMP > PA. PS-NPs exerted concentration-dependent effects: low concentrations activated adaptive pathways (including glutathione metabolism) to maintain homeostasis, whereas high concentrations disrupted photosynthesis and membrane integrity, reducing chlorophyll a levels by 20.84%-58.89% and suppressing algal growth. Quantitative PCR and microbial sequencing confirmed that P supplementation increased ARG abundances by 37.58%-59.34%, with organic phosphorus groups harboring higher ARG levels than those of IP groups. Low PS-NP concentrations further promoted ARGs by 16.21% via mobile genetic elements (intI1 and tnpA-04) that mediate horizontal gene transfer, whereas high PS-NP concentrations reduced ARGs by 2.70% through diversity suppression. Proteobacteria dominated, with Brevundimonas and Aquimonas identified as potential ARG hosts. Microbial community assembly was a primary driver of resistome profiles, alongside mobile genetic elements and P metabolism. These findings highlight that nutrient-nanoplastic interactions accelerate ARG propagation in microalgae-bacteria systems, providing insights for managing environmental antibiotic resistance.},
}

@article {pmid42336122,
year = {2026},
author = {Zhang, G and Zheng, Q and Hua, L and Dong, Q and Guo, H and An, M and Wang, T},
title = {Shaping antibiotic resistance gene fate in soil-plant systems: Dual roles of biochar physicochemical traits mediated by pyrolysis conditions.},
journal = {Environmental research},
volume = {306},
number = {Pt 1},
pages = {125097},
doi = {10.1016/j.envres.2026.125097},
pmid = {42336122},
issn = {1096-0953},
abstract = {Antibiotic resistance genes (ARGs), emerging contaminants spreading via horizontal gene transfer, threaten ecosystems and human health. Biochar (BC) is a widely used agricultural soil amendment, yet its effects on ARG dissemination remain controversial, likely dependent on pyrolysis conditions. This study applied wheat straw BC prepared under three distinct pyrolysis conditions, including open-flame combustion (BC-ZJ), 500°C hypoxic pyrolysis, and 500°C anaerobic pyrolysis, to a Brassica rapa L.-soil system for exploring ARG transfer impacts and mechanisms. BC application increased plant stem/leaf total ARG relative abundance by 20.68-71.59% and selectively enriched specific subtypes. BC-ZJ enriched multidrug resistance ARGs, whereas BC-Y500 and BC-W500 dramatically elevated aminoglycoside and tetracycline ARGs, and vancomycin and sulfonamide ARGs became undetectable. BC-ZJ (rich in oxygen-containing functional groups) stimulated microbial co-metabolism and promoted ARG proliferation and translocation into plant tissues. In contrast, BC-Y500 and BC-W500 (with larger micropore volumes and stable aromatic structures) exerted dual effects: potential adsorption of partial ARGs but selective enrichment of key ARG-hosting taxa (e.g., Pseudonocardia), leading to the accumulation of aph(3')-I and tetC in plant tissues. Structural equation modeling revealed that BC exerted a direct negative effect on ARG abundance, but this was overwhelmed by positive indirect effects via enhanced soil properties and bacterial community restructuring, leading to a net increase in ARG abundance. The bacterial community emerged as the dominant driver integrating the influences of BC properties, soil conditions, and mobile genetic elements. These findings demonstrate that biochar-mediated ARG regulation balances adsorptive inhibition and microbial stimulation in a pyrolysis-dependent manner. This study provides a mechanistic basis for engineering pyrolysis-optimized BC to mitigate agricultural ARG dissemination.},
}

@article {pmid42336203,
year = {2026},
author = {Zhang, T and Han, N and Peng, X and Qiang, Y and Li, X and Zhang, W},
title = {The Expanding Tet(X) Gene Family: Public Health Risks from Cross-Species Transmission Revealed by Genomic Big Data Mining.},
journal = {Journal of global antimicrobial resistance},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.jgar.2026.06.014},
pmid = {42336203},
issn = {2213-7173},
abstract = {OBJECTIVES: To investigate the tet(X) gene family, which confers resistance to all tetracycline antibiotics, in terms of diversity, dissemination dynamics, and evolutionary risks.

METHODS: We conducted a large-scale genomic data mining of 2 299 771 bacterial genomes. Tet(X) homologs were identified using BLAT. Phylogenetic analysis, plasmid identification, and epidemiological statistics were employed to elucidate the diversity, transmission history, and risk of tet(X).

RESULTS: We identified 4 208 tet(X) sequences within 3 744 high-quality bacterial genomes, representing 154 distinct variants. Strikingly, 124 of these were previously uncharacterized variants. These variants exhibited an average similarity of 91.93% to known types, with a maximum divergence of 106 SNPs. Tet(X) demonstrated robust cross-species transmission, being detected in 223 bacterial species. Plasmid-mediated horizontal gene transfer was identified as a major driver of its spread, with 1 800 sequences located on plasmids. We report the first genomic detection of tet(X) in three Vibrio cholerae genomes, signaling its intrusion into a critical human pathogen. Spatiotemporal analysis revealed that tet(X) variant diversity is the primary biological driver of its global dissemination (explaining 75.3% of variance). Modularity analysis identified hotspot species as major sources of novel variant emergence.

CONCLUSION: Our study unveils a vast and expanding "hidden" reservoir of tet(X) variants. The continuous generation of new variants, facilitated by plasmid-mediated horizontal gene transfer, along with their presence in key pathogens, underscores a critical public health threat. This research establishes a paradigm for big data-driven antimicrobial resistance surveillance, highlighting the need for targeted monitoring of biological and geographical hotspot.},
}

@article {pmid42337996,
year = {2026},
author = {Komijani, M and Maddahi, H and Rezaei, M and Abnosi, MH and Ahmed, AK},
title = {Bacteriophages in the Rhizosphere: Roles in Nutrient Cycling, Bacterial Community Structure, and Animal-Mediated Dispersal.},
journal = {MicrobiologyOpen},
volume = {15},
number = {3},
pages = {e70330},
pmid = {42337996},
issn = {2045-8827},
mesh = {*Rhizosphere ; *Bacteriophages/physiology ; *Soil Microbiology ; Animals ; *Bacteria/virology/metabolism ; Nutrients/metabolism ; Soil/chemistry ; Plant Roots/microbiology/virology ; Carbon/metabolism ; Nitrogen/metabolism ; },
abstract = {The rhizosphere, a critical soil layer around plant roots, is enriched with carbon from root exudates, influencing microbial communities that can either protect against or cause plant diseases. Bacteriophages significantly impact soil nutrient cycles and ecosystem processes through cell lysis and horizontal gene transfer. They play a vital role in the rhizosphere by affecting plant stress responses and climate adaptation. Bacteriophages exert a range of negative effects on Actinobacteria, impacting their ecological and physiological functions by diminishing Actinobacteria's roles in antibiotic production, soil health, and plant growth. Phage predation affects nutrient cycling by influencing nitrogen and carbon metabolism, with evidence showing that phages can alter microbial diversity and function, leading to changes in soil ammonium levels and carbon decomposition rates. In wastewater treatment, bacteriophages can improve process efficiency by targeting harmful bacteria, managing foam formation, and enhancing sludge reduction through enzymatic action. Additionally, bacteriophage dispersal mechanisms in the rhizosphere can be enhanced by rhizosphere-associated animals. Numerous invertebrate and vertebrate animals can significantly alter the rhizosphere environment by amplifying, mobilizing, and distributing both phages and bacterial hosts. Herein, three main mechanisms by which animals enhance the dispersal of bacteriophages in the rhizosphere are discussed. This review discusses bacteriophages' roles in soil ecosystems, highlighting their impact on nutrient cycling, plant health, and soil remediation, as well as animal-mediated phage dispersal mechanisms. Overall, while bacteriophages have potential biotechnological applications, their negative effects on microbial functions and nutrient cycling highlight the need for balanced use and further research.},
}

*Rhizosphere
*Bacteriophages/physiology
*Soil Microbiology
Animals
*Bacteria/virology/metabolism
Nutrients/metabolism
Soil/chemistry
Plant Roots/microbiology/virology
Carbon/metabolism
Nitrogen/metabolism

@article {pmid42341036,
year = {2026},
author = {Wang, Y and Wang, H and Lin, C and Wang, X},
title = {Chemical ecology and convergent evolution of natural hallucinogens: From ecological defense to conserved neural targets.},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {123},
number = {26},
pages = {e2535785123},
doi = {10.1073/pnas.2535785123},
pmid = {42341036},
issn = {1091-6490},
support = {82550005 W2512066//National Natural Science Foundation of China/ ; 2021ZD0203000(2021ZD0203003)//Brain Science and Brain-like Intelligence Technology-National Science and Technology Major Project/ ; 029GJHZ2024057GC//International Partnership Program of the Chinese Academy of Sciences/ ; },
mesh = {*Hallucinogens/chemistry/metabolism/pharmacology ; Animals ; Humans ; *Biological Evolution ; Psilocybin/chemistry/metabolism ; Mescaline/chemistry/metabolism ; Plants/metabolism ; Evolution, Molecular ; Ecology ; },
abstract = {Natural hallucinogenic compounds have arisen independently across plants, fungi, and animals, evolving into a diverse chemical arsenal that includes phenethylamines, indolealkylamines, and terpenoid scaffolds. Beyond clinical and cultural frameworks, their ecological origins and evolutionary trajectories may help explain why such potent modulators of perception, emotion, and cognition persist in nature. Here, integrating chemical ecology, comparative genomics, biosynthetic logic, and evolutionary biology, we propose that these molecules may function as defensive agents or symbiosis-associated manipulators of herbivore and pollinator behavior. A "building-block" biosynthetic logic links primary metabolism to convergent psychotropic scaffolds via a recurrent set of tailoring reactions, including decarboxylations and methylations. Recent advances illuminate mescaline biosynthesis in cacti, horizontal gene transfer of psilocybin clusters in fungi, and symbiont-derived alkaloids in grasses. We also assess the debate surrounding endogenous mammalian tryptamines, arguing that the leading hypothesis points toward sigma-1 receptor-mediated cytoprotection and stress responses, supported by convergent pharmacological and cellular evidence, rather than inherent hallucinogenic functions. Across kingdoms, natural hallucinogens appear to converge on conserved neural targets, including serotonergic and other neuromodulatory systems that are shared across phyla. From this perspective, human psychoactivity is likely an evolutionary by-product of molecules selected for ecological interactions with animals possessing deeply conserved receptor architectures. Framing hallucinogens through chemical ecology not only clarifies their origins but also highlights translational opportunities in target discovery, pathway engineering, and sustainable production, while emphasizing the need to integrate conservation, ethical sourcing, and benefit-sharing into the current hallucinogenic renaissance.},
}

*Hallucinogens/chemistry/metabolism/pharmacology
Animals
Humans
*Biological Evolution
Psilocybin/chemistry/metabolism
Mescaline/chemistry/metabolism
Plants/metabolism
Evolution, Molecular
Ecology

@article {pmid42343929,
year = {2026},
author = {Schliep, K and Vidal-García, M and Biancani, L and Henao-Díaz, LF and Ada, E and Justison, J and Solís-Lemus, C},
title = {tanggle: An R package for the visualization of phylogenetic networks.},
journal = {Applications in plant sciences},
volume = {14},
number = {3},
pages = {e70060},
pmid = {42343929},
issn = {2168-0450},
abstract = {PREMISE: Phylogenetic trees depict evolutionary relationships among taxa. However, they are strictly bifurcating structures that do not take into account several types of evolutionary events such as horizontal gene transfer, hybridization, or introgression. Although the development of new methods in phylogenetic networks has recently increased, limited visualization software is available to plot the phylogenetic networks.

METHODS AND RESULTS: Here, we present the R package tanggle, a visualization package for phylogenetic networks. Our package extends the widely used visualization package ggtree and allows a variety of input data from DNA sequences to extended Newick format; it also builds on the flexibility of ggplot2 to manipulate colors and other plot characteristics. In addition, our package allows for the inclusion of images and mapped morphological and geographical characteristics on the network.

CONCLUSIONS: In response to growing demands for reproducible, open-source research, tanggle facilitates the production of script-based, publication-quality figures rather than graphics manually created with design software. By embedding figure code and metadata directly within analysis pipelines, tanggle improves transparency, traceability, and version control; enables automated regeneration of figures as data or methods change; and simplifies sharing and reuse of visualizations.},
}

@article {pmid42345440,
year = {2026},
author = {Matrougui, I and Savisaar, R and Dias, C and Calatayud, PA and Malusi, P and Muller, H and Mwangangi, E and Obonyo, J and Oukkal, S and Charlat, S and Gilbert, C},
title = {Exploring the determinants of polydnavirus chromosomal integration across host-parasitoid wasp systems.},
journal = {Genome biology and evolution},
volume = {},
number = {},
pages = {},
doi = {10.1093/gbe/evag150},
pmid = {42345440},
issn = {1759-6653},
abstract = {Polydnaviruses (PDV) are domesticated viruses integrated into the genome of parasitoid wasps. During oviposition, female wasps inject into their host both eggs and PDV particles containing wasp DNA circles. Circle-borne genes are expressed in the host and suppress its immune response, ensuring successful development of the wasp larvae. Several dozen distinct circles have been distinguished on the basis of their sequence and location within the wasp genome. Interestingly, these circles display very different propensities to integrate into the caterpillar genome but the factors influencing this variation remain poorly understood. Here, we experimentally quantified and modelled both the number of PDV integrations and the abundance of injected PDV circles in 8 distinct wasp-host systems. Integrations into the host genomes were observed at rates ranging across wasp species from 0.28 to 14.5 integrations per host haploid genome. Our analyses reveal that integration efficiency varies among circles. We particularly highlight a specific circle, referred to as circle 1, which we find to be both the most abundantly injected and the most efficiently integrated, even after controlling for the direct effects of the quantity injected on the total number of integrations. This pattern is compatible with the view that both the quantity and integration efficiency of injected circles may constitute key components of parasitism success. Finally, our analyses indicate that integration efficiency is reduced in non-suitable hosts, suggesting a possible contribution of host factors to the regulation of PDV circle integration.},
}

@article {pmid42345582,
year = {2026},
author = {Zhang, J and Dong, X and Zeng, Z and Du, Y},
title = {Genome analysis of Staphylococcus caprae indicates potential health risks associated with antimicrobial resistance and virulence factors.},
journal = {Canadian journal of microbiology},
volume = {72},
number = {},
pages = {1-9},
doi = {10.1139/cjm-2026-0024},
pmid = {42345582},
issn = {1480-3275},
mesh = {*Virulence Factors/genetics ; *Genome, Bacterial ; *Staphylococcus/genetics/drug effects/pathogenicity/classification ; *Staphylococcal Infections/microbiology ; Phylogeny ; Anti-Bacterial Agents/pharmacology ; *Drug Resistance, Multiple, Bacterial/genetics ; *Drug Resistance, Bacterial ; Humans ; Bacterial Proteins/genetics ; Gene Transfer, Horizontal ; },
abstract = {Staphylococcus caprae is an emerging coagulase-negative staphylococcal pathogen. This study performed pan-genome analysis to comprehensively characterize the genomic landscape of S. caprae. Phylogenomic reconstruction confirmed that it forms a distinct monophyletic clade from closely related species (Staphylococcus epidermidis and Staphylococcus capitis). Pan-genome analysis revealed an open genome (γ = 0.149 according to Heap's law) comprising 3967 gene families, 53.5% of which constitute the core genome enriched in essential metabolic functions. Cloud gene families showed enrichment in defense mechanisms and traits associated with genomic plasticity. A total of 17 antimicrobial resistance (AMR) genes were identified, most of which were scattered sporadically across S. caprae genomes in the form of cloud genes, which indicates horizontal gene transfer. The coexistence of multiple resistance determinants (e.g., mecA, blaZ, erm(A)) could potentially lead to the development of high-risk multidrug-resistant phenotypes, which would severely limit the available therapeutic options. Virulence genotypic profiling revealed conserved pathogenic mechanisms, including the complete icaADBC operon (involved in biofilm formation), a type VII secretion system and iron acquisition systems (isd). These findings provide a pan-genome-level view of S. caprae and highlight its potential role as a reservoir of AMR genes and conserved virulence-related traits.},
}

*Virulence Factors/genetics
*Genome, Bacterial
*Staphylococcus/genetics/drug effects/pathogenicity/classification
*Staphylococcal Infections/microbiology
Phylogeny
Anti-Bacterial Agents/pharmacology
*Drug Resistance, Multiple, Bacterial/genetics
*Drug Resistance, Bacterial
Humans
Bacterial Proteins/genetics
Gene Transfer, Horizontal

@article {pmid42345603,
year = {2026},
author = {Butenko, A and Lukes, J},
title = {Lack of evidence for the presence of plastids in the evolutionary history of kinetoplastid protists.},
journal = {Folia parasitologica},
volume = {73},
number = {},
pages = {},
pmid = {42345603},
issn = {1803-6465},
mesh = {*Plastids/genetics ; Phylogeny ; Gene Transfer, Horizontal ; *Kinetoplastida/genetics/classification ; *Evolution, Molecular ; *Biological Evolution ; *Euglenozoa/genetics ; },
abstract = {The discovery of multiple metabolic enzymes encoded by genes of apparent plant or cyanobacterial origin in trypanosomatids led to the influential hypothesis that the common ancestor of Euglenozoa harboured a plastid that was subsequently lost in kinetoplastids. Here, we critically re-evaluate this hypothesis using an expanded, phylogenetically balanced dataset comprising 299 eukaryotic and 102 bacterial species. We reassess the evolutionary histories of 16 genes encoding proteins previously interpreted as evidence for an ancestral euglenozoan plastid using state-of-the-art maximum-likelihood and Bayesian phylogenetic approaches, supplemented by topology tests. Our analyses reveal that none of the examined genes provides compelling support for a plastid-bearing ancestor of Euglenozoa. Instead, these enzymes display heterogeneous evolutionary origins consistent with multiple independent horizontal gene transfer events between euglenozoans and diverse bacterial (distinct from cyanobacteria) and eukaryotic donors. Only the gene encoding a vacuolar H[+]-pyrophosphatase, an electrogenic proton pump, shows limited affinity to chloroplast-bearing lineages, and this signal alone is insufficient to infer plastid ancestry. Taken together, our results strongly suggest a horizontal gene transfer from various non-plastid bearing lineages over the hypothesis of plastid presence in the euglenozoan common ancestor with subsequent loss in kinetoplastids, diplonemids, and non-photosynthetic euglenids.},
}

*Plastids/genetics
Phylogeny
Gene Transfer, Horizontal
*Kinetoplastida/genetics/classification
*Evolution, Molecular
*Biological Evolution
*Euglenozoa/genetics

@article {pmid42345817,
year = {2026},
author = {Stefan, G and Gurau, MR and Ciocîrlie, N and Tudor, L and Bărăităreanu, S and Tache-Codreanu, DL and Sporea, C and Gligor, A and Iancu, I and Herman, V},
title = {Horizontal Gene Transfer in Listeria monocytogenes: Evolution of Antimicrobial Resistance and Virulence in a One Health Context.},
journal = {Biology},
volume = {15},
number = {12},
pages = {},
pmid = {42345817},
issn = {2079-7737},
abstract = {Listeria monocytogenes is a ubiquitous Gram-positive bacterium responsible for listeriosis, a foodborne zoonotic disease affecting humans and animals. Although infection in immunocompetent individuals is often asymptomatic or limited to mild self-limiting gastroenteritis, Listeria monocytogenes may cause severe invasive disease in vulnerable groups, including pregnant women, neonates, elderly individuals, and immunocompromised patients. Although the incidence of listeriosis is relatively low compared with many other foodborne pathogens, the high hospitalization and mortality rates associated with clinical cases make this bacterium a major concern for food safety and public health. The evolutionary success of L. monocytogenes reflects the interaction between a conserved core genome and a dynamic accessory genome shaped by horizontal gene transfer (HGT), ecological selection, and expansion of specific clones. Transient intestinal carriage in humans and animals, potentially influenced by gut microbiome composition, creates ecological interfaces where plasmids, transposons, prophages, and integrative conjugative elements contribute to the exchange of antimicrobial resistance determinants, virulence factors, and stress tolerance systems. Virulence diversification is further influenced by the differential distribution of pathogenicity islands such as LIPI-1, LIPI-3, and LIPI-4 across specific clonal lineages. These evolutionary processes occur across interconnected farm, food-production, environmental, and clinical ecosystems consistent with the One Health framework. Advances in whole-genome sequencing have clarified lineage-specific gene flow, expansion of specific clones, and the dynamics of the resistome and mobilome in L. monocytogenes populations. This narrative review aims to synthesize current knowledge on the mobile genetic elements and ecological interfaces that shape horizontal gene transfer in L. monocytogenes. Its novelty lies in integrating antimicrobial resistance, virulence-associated genomic islands, stress adaptation, and gut microbiome-mediated selection within a One Health and metapopulation framework. The main message of this review is that HGT should be interpreted as a context-dependent contributor to L. monocytogenes adaptation, acting together with clonal background, ecological selection, and mobile genetic elements.},
}

@article {pmid42345828,
year = {2026},
author = {Xia, X},
title = {Retroviruses and Cancer: Coevolution and Genetic Exchanges Between the Viral and the Host Genomes.},
journal = {Biology},
volume = {15},
number = {12},
pages = {},
pmid = {42345828},
issn = {2079-7737},
support = {RGPIN/2024-05641//NSERC/ ; },
abstract = {Retroviruses, after their genomes are integrated into the host genome, replicate through host cell replication. In this hitchhiking phase, their only way of increasing their fitness is to encourage the host cell to have unregulated, rapid cell replication. The v-Src gene in avian sarcoma virus and the v-sis gene in the simian sarcoma virus were originally mined from the host genome by the virus to increase host cell replication rate, with the corresponding host cellular counterparts c-Src (non-receptor tyrosine kinase) and c-sis (platelet-derived growth factor). The resulting out-of-control replication ultimately would lead to cancer. The battle between the host and the retroviruses left many retroviral corpses known as endogenous retroviruses, and the host occasionally domesticates retroviral genes. The syncytins (whose fusogenic function is crucial for the trophoblast fusion and the formation of a syncytium during placenta morphogenesis) and suppressyn (which serves the dual function of regulating syncytialization and host resistance against retroviruses) are examples of successful domestication. Syncytin-1 and suppressyn have each been "domesticated" independently multiple times by different mammalian lineages. Molecular phylogenetics is an essential tool for tracing the evolutionary trajectories of such genetic exchanges between retroviruses and their hosts and for determining the direction of the genetic exchange.},
}

@article {pmid42346416,
year = {2026},
author = {Duarte-Martínez, MDR and Amaro-Reyes, A and Campos-Guillen, J and Ramos-López, MA and Rodríguez-de León, E and Escamilla-García, M and Vallejo-Becerra, V and Álvarez-López, A and Mendoza-Burguete, Y and López Velarde-Santos, M and Pool, H and Ramírez-Granados, L and Chaparro-Sánchez, R and Rodríguez-Morales, JA},
title = {Antibiotic Resistance Genes in Wastewater: A Systematic PRISMA-Guided Review on Risk, Genetic Transfer, and the Effectiveness of the Photo-Fenton Process for Their Removal.},
journal = {Journal of xenobiotics},
volume = {16},
number = {3},
pages = {},
doi = {10.3390/jox16030094},
pmid = {42346416},
issn = {2039-4713},
support = {2047714//Secretaría de Ciencia, Humanidades, Tecnología e Innovación (SECIHTI)/ ; SIIP-2026//Autonomous University of Queretaro/ ; },
abstract = {Antimicrobial resistance (AMR) constitutes a growing global threat, facilitated by the dissemination of antibiotic resistance genes (ARGs) through wastewater treatment plants (WWTPs). This systematic review, conducted following the PRISMA guidelines, compiles the risks associated with ARGs, as well as the factors that promote horizontal gene transfer (HGT) and the technologies applied for their removal. The literature shows that WWTPs act as reservoirs, where biological treatment conditions and the presence of sub-inhibitory contaminants (antibiotics, metals, and pharmaceuticals) accelerate HGT. Although conventional methods (chlorination, ozonation, UV) are effective at eliminating antibiotic-resistant bacteria (ARB), their ability to degrade persistent genetic material is insufficient. Therefore, advanced oxidation processes (AOPs) emerge as a key solution, with the photo-Fenton process standing out due to efficiently generating hydroxyl radicals, achieving the degradation of ARGs, an essential step to mitigate the spread of AMR into the environment.},
}

@article {pmid42171704,
year = {2026},
author = {Jayaswal, PK and Singh, NK},
title = {Evolutionary Study of Transposable Elements: Structural Characterization and Phylogenomic Profiling in Plant Genomes.},
journal = {Journal of molecular evolution},
volume = {94},
number = {3},
pages = {424-439},
pmid = {42171704},
issn = {1432-1432},
mesh = {*DNA Transposable Elements/genetics ; *Genome, Plant/genetics ; Evolution, Molecular ; Phylogeny ; Gene Transfer, Horizontal ; Plants/genetics ; Genomics/methods ; Terminal Repeat Sequences/genetics ; Zea mays/genetics ; },
abstract = {Transposable elements (TEs) are dynamic DNA sequences that play a significant role in shaping genome structure and function in eukaryotic species. Advances in next-generation sequencing technologies have enhanced our understanding of the abundance and diversity of transposable element families. Transcriptionally active TEs contribute to intra-species genetic variability and facilitate adaptation to environmental stressors, such as heat, drought, and salinity, by inducing mutations, modulating gene expression, and promoting genome rearrangements. Recent studies highlight the important role of horizontal transfer and vertical transmission mechanisms in the evolution of Class I and Class II TE families. The Opie and Ji families of LTR elements serve as examples of conserved TEs that contribute to the expansion of the maize genome. In contrast to RIRE1, which remains relatively stable, Tos17 is largely inactive under normal conditions but can be activated under stress, such as tissue culture, thereby contributing to genome dynamics. This review explores key examples of horizontal transfer and vertical transmission of TEs in plant species, along with their structural features, evolutionary trajectories, and divergence patterns.},
}

*DNA Transposable Elements/genetics
*Genome, Plant/genetics
Evolution, Molecular
Phylogeny
Gene Transfer, Horizontal
Plants/genetics
Genomics/methods
Terminal Repeat Sequences/genetics
Zea mays/genetics

@article {pmid42328872,
year = {2026},
author = {Hullinger, AC and Callahan, VE and Dalia, TN and Dalia, AB},
title = {Low-affinity DNA-binding promotes cooperative activation of natural transformation in Vibrio cholerae.},
journal = {Journal of bacteriology},
volume = {},
number = {},
pages = {e0022426},
doi = {10.1128/jb.00224-26},
pmid = {42328872},
issn = {1098-5530},
abstract = {DNA-binding transcriptional regulators control gene expression in response to environmental cues. A subset of these proteins, called transmembrane transcriptional regulators (TTRs), directly bind DNA to regulate transcription while remaining anchored in the cytoplasmic membrane. Prior work has shown that in the presence of the polysaccharide chitin, two TTRs, TfoS and ChiS, coordinate to induce the expression of TfoR, a small RNA that is critical for natural transformation in Vibrio cholerae. Specifically, it was shown that ChiS recruits the PtfoR locus to the membrane, thereby allowing subsequent activation of this promoter by TfoS. However, it was also shown that increasing TfoS protein levels bypasses this coordination, allowing TfoS to activate the promoter independently. It therefore remains unclear which molecular mechanisms drive the requirement for ChiS under native conditions. Here, we show that ChiS binds PtfoR with a higher affinity than TfoS. We hypothesized that the low affinity of TfoS for PtfoR helps reinforce its dependence on ChiS for activation. To test this, we isolated a mutant allele of the TfoS DNA-binding domain with higher affinity for PtfoR. We show that this high-affinity TfoS allele promotes ChiS-independent activation of PtfoR and dysregulates chitin-dependent phenotypes in V. cholerae. These results demonstrate that the relative DNA-binding affinity of these TTRs facilitates their coordination, which is necessary for optimal V. cholerae fitness on chitin.IMPORTANCEDNA-binding transmembrane transcriptional regulators (TTRs) are critical for some bacterial species to properly sense and respond to their environments. Recent work highlights that pairs of TTRs can coordinate their activities to regulate gene expression, allowing them to sensitively control behaviors like virulence and horizontal gene transfer. However, the mechanisms that enable this coordination remain poorly understood. Here, we show that the relative DNA-binding affinity of paired TTRs is a critical feature that can drive their coordination.},
}

@article {pmid42330923,
year = {2026},
author = {Hansson, EM and Brockhurst, MA},
title = {Symbiosis: Mutualism on the move.},
journal = {Current biology : CB},
volume = {36},
number = {12},
pages = {R693-R695},
doi = {10.1016/j.cub.2026.04.013},
pmid = {42330923},
issn = {1879-0445},
mesh = {*Symbiosis/genetics ; *Gene Transfer, Horizontal ; *Biological Evolution ; },
abstract = {Symbiosis underlies the evolution of complex life and the function of ecosystems worldwide, yet the origins of symbioses are poorly understood. A new study reveals how symbiotic bacteria are created by horizontal gene transfer.},
}

*Symbiosis/genetics
*Gene Transfer, Horizontal
*Biological Evolution

@article {pmid42074541,
year = {2026},
author = {Bini, C and Trasatti, A and Giorgetti, A and Amurri, S and Fazio, G and Pelotti, S},
title = {A Mini Narrative Review on Human DNA Transfer Involving Dogs and Cats and Their Role in Forensic Investigation.},
journal = {Genes},
volume = {17},
number = {4},
pages = {},
pmid = {42074541},
issn = {2073-4425},
mesh = {Animals ; Cats ; Dogs ; Humans ; *DNA/genetics ; *Forensic Genetics/methods ; *Gene Transfer, Horizontal ; },
abstract = {BACKGROUND/OBJECTIVES: The potential role of domestic animals in DNA transfer, persistence, prevalence and recovery (TPPR) warrants careful consideration in forensic contexts. This mini narrative review aims to provide an updated overview of human DNA transfer involving household dogs and cats as vectors, to clarify their forensic relevance, and to identify key considerations for the design of future experimental research.

METHODS: A narrative review was conducted using multiple electronic databases as search engines without restriction related to the timing of publication.

RESULTS: Experimental evidence shows that dogs and cats readily acquire human DNA following even brief contact, acting as reservoirs for primary DNA transfer. Once acquired, human DNA can be redistributed via secondary transfer to a wide range of substrates, such as gloved hands, vehicle interiors, clothing, and surfaces. Moreover, multi-step and higher-order transfer events have been documented, highlighting the complexity of DNA transfer involving household animals.

CONCLUSIONS: The sampling on pets may be included in certain scenarios and may contribute to building a Bayesian network together with the experimental data. To deal with uncertainty during probability assignment, more experimental data, especially addressing the main variables impacting DNA TPPR involving pets, should be generated and are highly needed to assist in activity level evaluation.},
}

Animals
Cats
Dogs
Humans
*DNA/genetics
*Forensic Genetics/methods
*Gene Transfer, Horizontal

@article {pmid42202780,
year = {2026},
author = {Montoya, AP and Jensen, KT and Griffitts, JS and Porter, SS},
title = {The evolutionary genomics of novel endosymbiosis in wild rhizobia bacteria.},
journal = {Current biology : CB},
volume = {36},
number = {12},
pages = {2967-2979.e4},
doi = {10.1016/j.cub.2026.04.071},
pmid = {42202780},
issn = {1879-0445},
mesh = {*Symbiosis/genetics ; Nitrogen Fixation/genetics ; *Genome, Bacterial ; Phylogeny ; *Rhizobium/genetics/physiology ; Genomics ; *Biological Evolution ; *Evolution, Molecular ; Gene Transfer, Horizontal ; Root Nodules, Plant/microbiology ; Interspersed Repetitive Sequences ; },
abstract = {The advent of endosymbiosis underlies evolutionary innovation and ecosystem function. However, whether free-living partners tend to benefit or exploit each other during the early stages of novel endosymbiosis remains a dilemma. Rhizobia soil bacteria can initiate root nodules and fix nitrogen for host plants as endosymbionts due to genes carried on mobile genetic elements such as the symbiosis island (SI). We conjugated marked SIs into the genomes of non-nodulating strains, which was sufficient to generate de novo root nodule-forming endosymbionts. Most novel endosymbionts originated as commensals that incurred no detectable costs to host plants, in contrast to predictions of exploitation. In fact, a third of novel endosymbionts originated as nitrogen-fixing mutualists. Consistent with phylogenetic limits to transfer of mobile genetic element function, novel endosymbionts derived from more closely related SI donor and recipient strains showed greater nitrogen fixation. However, consistent with selection on the SI for broad horizontal transfer, we did not detect phylogenetic limits to SI transmission, and the SI was able to displace other genomic elements residing at its characteristic tRNA gene insertion site. We thus provide genetic, genomic, and functional evidence of how mobile genetic elements can potentiate and constrain major evolutionary transitions to expand bacterial niches, with cascading impacts on the fitness of host organisms.},
}

*Symbiosis/genetics
Nitrogen Fixation/genetics
*Genome, Bacterial
Phylogeny
*Rhizobium/genetics/physiology
Genomics
*Biological Evolution
*Evolution, Molecular
Gene Transfer, Horizontal
Root Nodules, Plant/microbiology
Interspersed Repetitive Sequences

@article {pmid42326089,
year = {2026},
author = {Yadav, MV and Pawar, S and Patil, S},
title = {An Overview of Mobile Colistin Resistance (mcr) Genes in Gram-Negative Bacilli.},
journal = {Cureus},
volume = {18},
number = {5},
pages = {e109203},
pmid = {42326089},
issn = {2168-8184},
abstract = {The increasing spread of mobile colistin resistance (mcr) genes is becoming a major concern in the treatment of infections caused by multidrug-resistant Gram-negative bacilli. Colistin is often used as a last treatment option, but the emergence of mcr genes is reducing its effectiveness. These genes are most commonly found in bacteria, such as Escherichia coli, Klebsiella pneumoniae, and Salmonella, and have also been reported, though less frequently, in organisms like Pseudomonas aeruginosa. This review provides an overview of the occurrence, diversity, and mechanisms of mcr genes in Gram-negative bacilli. These genes are usually carried on plasmids, which allows them to spread easily between different bacteria. They produce enzymes that modify lipid A in the bacterial outer membrane, reducing the ability of colistin to bind and act effectively. In addition, changes in chromosomal regulatory systems such as polymyxin resistance A and B (pmrAB), phosphate regulon P and Q (phoPQ), and polymyxin adaptive resistance R and S (parRS) can further increase resistance. The spread of mcr genes is mainly driven by horizontal gene transfer, making it easier for resistance to move across different bacterial species and environments. From a clinical point of view, infections caused by mcr-positive bacteria can make treatment more difficult, increase the risk of complications, and put more pressure on healthcare systems. Therefore, early detection, regular monitoring, and careful use of antibiotics are important to control the spread of resistance. Understanding how these genes spread and persist in different environments will be important for developing better strategies to manage this growing problem.},
}

@article {pmid42326400,
year = {2026},
author = {Jallow, L and Bojang, A and Bajinka, O},
title = {Conjugation as an evolutionary bottleneck in antimicrobial resistance spread.},
journal = {Frontiers in microbiology},
volume = {17},
number = {},
pages = {1863866},
pmid = {42326400},
issn = {1664-302X},
abstract = {Antimicrobial resistance (AMR) is commonly framed as a consequence of mutation and selection, yet this perspective does not fully explain the speed and scale of global resistance dissemination. Here, we argue that AMR is better understood as an amplification problem, in which horizontal gene transfer particularly conjugation governs the spread of resistance genes across bacterial populations and ecological compartments. Conjugative plasmids couple high transfer efficiency with broad host range, enabling rapid dissemination of resistance determinants, including those conferring resistance to last-resort antibiotics. This review synthesizes evidence showing that conjugation is shaped by tightly constrained trade-offs between transfer efficiency, fitness cost, plasmid copy number, and ecological context. These constraints render conjugation a rate-limiting step in dissemination dynamics, such that even modest reductions in transfer efficiency can substantially reduce plasmid persistence and spread. At the same time, plasmids exhibit adaptive features, including compensatory evolution and dynamic regulation of replication, that stabilize their persistence and complicate intervention. This duality positions conjugation as both a central driver of AMR and a tractable therapeutic target. We review emerging strategies to disrupt conjugation, including small-molecule inhibitors, CRISPR-based systems, phage approaches, and ecological interventions, and highlight key challenges related to delivery, evolutionary escape, and real-world implementation. We propose that targeting gene flow rather than gene emergence alone offers a complementary strategy for controlling AMR. By reframing conjugation as a controllable bottleneck in resistance amplification, future interventions may shift the trajectory of AMR from expansion toward containment.},
}

@article {pmid42327055,
year = {2026},
author = {Mallick Gupta, A and Arevalo, P and Anne Taylor, E},
title = {HepI and OpsX are functionally coupled but evolutionarily asymmetric heptosyltransferase variants: ecological transitions and operon modularization drive divergent constraints and flexibility.},
journal = {bioRxiv : the preprint server for biology},
volume = {},
number = {},
pages = {},
doi = {10.64898/2026.06.09.731171},
pmid = {42327055},
issn = {2692-8205},
abstract = {UNLABELLED: Lipopolysaccharide (LPS) inner-core biosynthesis is classically initiated by a heptosyltransferase enzyme most commonly Heptosyltranferase I (HepI), a conserved WaaC-like enzyme. An alternative heptosyltranferase variant, OpsX, occurs alone in a subset of Gram-negative bacteria and co-exist with WaaC-like enzyme within the same genome of other organisms, raising questions about the origin of these two vairants and their functional partitioning. Here, we present a comparative evolutionary analysis of HepI (K02841) and OpsX (K12982) across Gram-negative bacteria to resolve their functional coupling and divergence. Selection analyses reveal a consistent evolutionary asymmetry, with OpsX exhibiting elevated ω values relative to HepI across global datasets and within genomes encoding both systems. Residue-level analyses indicate conserved catalytic cores in both enzymes, but a broader distribution of relaxed constraints in OpsX, suggesting differential partitioning of functional pressure. HepI has undergone intensified purifying selection in host-associated lineages, whereas OpsX shows no corresponding shift, indicating distinct responses to ecological context. Gene-species tree reconciliation further reveals contrasting horizontal gene transfer (HGT) architectures: HepI displays an ecologically structured network enriched in pathogen- and opportunist-associated lineages, with recurrent hub-mediated exchanges and deeper lineage-integrated events, whereas OpsX exhibits a diffuse transfer regime dominated by non-pathogenic taxa and primarily recent terminal acquisitions. These differences persist in genomes co-encoding both systems, where HepI transfer signal remains strongly associated with lifestyle, while OpsX is largely uncoupled from ecological structure. Analysis of operon architecture reveals pathway partitioning between the two genes: HepI is embedded in a conserved downstream operon linked to glycosyltransferase-mediated core assembly, whereas OpsX occurs in a more variable context enriched for upstream ADP-heptose precursor biosynthesis genes. In dual-system genomes, HepI is reduced to a minimal downstream module while OpsX retains upstream functions, indicating coordinated operon modularization. Together, HepI and OpsX form a functionally coupled but evolutionarily asymmetric system shaped by ecological transitions and genomic reorganization.

HIGHLIGHTS: HepI and OpsX represent functionally coupled but evolutionarily asymmetric LPS inner-core biosynthesis systems across Gram-negative bacteria.OpsX shows relaxed selective constraint and a diffuse horizontal gene transfer pattern, whereas HepI is under stronger purifying selection and ecologically structured transfer.Operon organization reveals pathway modularization, with HepI embedded in conserved downstream assembly modules and OpsX retaining upstream precursor-associated flexibility.},
}

@article {pmid42327259,
year = {2026},
author = {García-Villada, L and Shore, BA and Kiser, K and Russ, IG and Gabel, SA and Mueller, GA and Degtyareva, NP and Doetsch, PW},
title = {Redox stress agents strongly enhance mutagenesis during horizontal gene transfer in bacteria and leave distinct mutational and metabolic footprints.},
journal = {bioRxiv : the preprint server for biology},
volume = {},
number = {},
pages = {},
doi = {10.64898/2026.06.04.730102},
pmid = {42327259},
issn = {2692-8205},
abstract = {Redox stress induces DNA mutations that contribute to chronic conditions affecting human health and to the emergence of antibiotic resistance. Yet, the impact of redox stress-induced mutagenesis remains difficult to decipher because redox agents are diverse and produce hard-to-detect mutational outcomes. Single-stranded DNA (ssDNA) provides a useful tool for studying mutagenic effects of redox agents, as it is particularly susceptible to damage and cannot be repaired by most DNA repair pathways. Here, we established a protocol to investigate redox stress-induced mutagenesis based on the Escherichia coli conjugative ssDNA that is transferred from donor to recipient cells. Using the environmentally relevant redox agents, potassium bromate and hydrogen peroxide, we show that the F episome is remarkably sensitive to weak mutagens during conjugation, enabling the detection of significant differences in mutational spectra induced by these agents. We support our findings with metabolomic analysis, which reveals agent-specific responses in E. coli . We compare these results with those obtained using a yeast ssDNA reporter and conclude that redox-induced mutagenesis depends, among other factors, on the metabolic context of the analysed system. These findings have important implications because the high sensitivity of conjugation-associated ssDNA to environmental mutagens may contribute to the evolution of antibiotic resistance.},
}

@article {pmid42002165,
year = {2026},
author = {Sato, N and Takano, H},
title = {Diverse origins of peptidoglycan biosynthesis enzymes in Glaucophyta and Viridiplantae.},
journal = {Molecular phylogenetics and evolution},
volume = {221},
number = {},
pages = {108621},
doi = {10.1016/j.ympev.2026.108621},
pmid = {42002165},
issn = {1095-9513},
mesh = {*Peptidoglycan/biosynthesis/genetics ; *Phylogeny ; *Glaucophyta/genetics/enzymology/classification ; *Evolution, Molecular ; Gene Transfer, Horizontal ; Cyanobacteria/genetics ; Sequence Analysis, DNA ; Chlorophyta/genetics/enzymology ; },
abstract = {Chloroplast peptidoglycan is considered a remnant inherited from the ancestral cyanobacterial endosymbionts and has served as visual evidence for the endosymbiotic theory of chloroplasts. While peptidoglycan has been identified in the glaucophyte Cyanophora paradoxa and the moss Physcomitrium patens, it is absent in red algae. To clarify the origins and phylogenetic relationship of peptidoglycan in various plant and algal groups, we examined the eleven major enzymes involved in peptidoglycan synthesis across the genomic data of 60 species within the Archaeplastida. Our findings revealed that peptidoglycan synthesis enzymes were present in many species of Glaucophyta and Viridiplantae. A complete set of eleven enzymes was found in many species of Streptophyta and Chlorophyta among green plants. Phylogenetic analysis indicated that Glaucophyta and Viridiplantae are monophyletic in the trees of MurA, MraY, and MurJ, which are derived from gene transfers from Cyanobacteria. The two lineages are closely related but not monophyletic in the PBP1 tree, which originated from Cyanobacteria/Melainabacteria. The two lineages were also monophyletic in the trees of MurD and MurE, though these enzymes did not originate from Cyanobacteria. The origins of the other enzymes were more diverse: those from Glaucophyta and Viridiplantae were not monophyletic and had various bacterial origins. These results suggest that peptidoglycan is no longer evidence for the endosymbiotic theory of chloroplast origin. We discuss potential scenarios for how peptidoglycan synthesis enzymes might have been acquired, depending on whether we assume or do not assume a cyanobacterial origin of chloroplasts.},
}

*Peptidoglycan/biosynthesis/genetics
*Phylogeny
*Glaucophyta/genetics/enzymology/classification
*Evolution, Molecular
Gene Transfer, Horizontal
Cyanobacteria/genetics
Sequence Analysis, DNA
Chlorophyta/genetics/enzymology

@article {pmid42317875,
year = {2026},
author = {Kadam, AC and Patil, HV and Patil, SR},
title = {From Susceptible to Resistant: The Emergence of Carbapenemase-Producing Escherichia coli.},
journal = {Cureus},
volume = {18},
number = {5},
pages = {e109096},
pmid = {42317875},
issn = {2168-8184},
abstract = {Carbapenemase-producing Escherichia coli (E. coli) has emerged as a critical contributor to antimicrobial resistance (AMR), significantly compromising the efficacy of last-resort carbapenem antibiotics. Carbapenemase-producing E. coli has significantly reduced the effectiveness of carbapenems, which were previously considered last-resort antibiotics for treating severe infections caused by extended-spectrum β-lactamase (ESBL)-producing organisms. Numerous β-lactam antibiotics, including carbapenems, are hydrolyzed by these enzymes, which results in fewer therapy choices, greater rates of treatment failure, and higher rates of morbidity and death. Travel, medical tourism, globalization, and poor infection control practices contribute to the development of resistant strains. AMR spreads more quickly in nations such as India due to factors such as over-the-counter antibiotic usage, inadequate antimicrobial stewardship, and a shortage of diagnostic infrastructure. The high frequency of E. coli in clinical infections and its notable resistance to commonly utilized antibiotics are highlighted by surveillance data from national programs like the ICMR-AMRSN. Both intrinsic and acquired mechanisms contribute to resistance in E. coli. ESBLs, AmpC, and carbapenemases are clinically relevant families of β-lactamases. Carbapenemases fall into three categories: Class A (KPC, for example), Class B (metallo-β-lactamases, such as New Delhi metallo-β-lactamase (NDM), Verona integron-borne metallo-β-lactamase (VIM), and Imipenemase (IMP), and Class D (OXA-type enzymes). Many of these enzymes are plasmid-mediated and capable of rapid horizontal gene transfer.},
}

@article {pmid42318064,
year = {2026},
author = {Li, XT and Zhang, X and Liang, ZL and Jiang, Z and Huang, Y and Han, YQ and Tan, ZB and Ying-Liu, and Liu, ZH and Yin, HQ and Liu, SJ and Jiang, CY},
title = {A culturomics biobank decodes extremophile evolution and metabolism in acid mine drainage.},
journal = {Environmental science and ecotechnology},
volume = {32},
number = {},
pages = {100722},
pmid = {42318064},
issn = {2666-4984},
abstract = {Extreme environments such as acid mine drainage (AMD) host highly specialized microbial communities that drive profound biogeochemical cycles. Within these ecosystems, iron- and sulfur-metabolizing taxa catalyze mineral weathering, generating intense acidity and mobilizing heavy metals. However, more than 97% of these microorganisms remain uncultured "microbial dark matter," heavily restricting our understanding of extremophile metabolism and adaptation. Here we present the Microbial Biobank of AMD (mbAMD), a culturomics-derived collection of 652 isolates spanning 42 species-including 21 novel taxa-that achieves 86.7% coverage of the global AMD core microbiome. Functional validation demonstrates that 36 of these taxa possess active iron or sulfur metabolic capacities, including the discovery of the first pure cultures of acid-tolerant sulfate reducers. Comparative genomic analyses across these isolates reveal that extreme environmental adaptation is predominantly driven by pervasive horizontal gene transfer. Specifically, extremophiles preferentially acquire adaptive genes governing acid tolerance and metal resistance from phylogenetically proximal relatives rather than distant donors. These findings elucidate the modular evolutionary strategies of extremophiles and provide critical functional resources for advancing biohydrometallurgy and environmental bioremediation. This mbAMD resource will accelerate biohydrometallurgical process optimization and environmental bioremediation strategies while advancing evolutionary microbial ecology research.},
}

@article {pmid42319502,
year = {2026},
author = {Ahmad, R and Ullah, Z and Li, M and Tong, Y},
title = {Emergence, evolution, and global dissemination of antimicrobial resistance: A One Health review.},
journal = {Archives of microbiology},
volume = {208},
number = {9},
pages = {},
pmid = {42319502},
issn = {1432-072X},
mesh = {Humans ; Animals ; *Anti-Bacterial Agents/pharmacology/therapeutic use ; *Drug Resistance, Bacterial/genetics ; *One Health ; *Bacteria/drug effects/genetics ; Global Health ; Gene Transfer, Horizontal ; Bacterial Infections/microbiology/drug therapy ; Drug Resistance, Multiple, Bacterial ; },
abstract = {Antimicrobial resistance (AMR) is a critical global health threat that undermines the treatment of infections and compromises medical interventions. AMR develops when microorganisms evolve mechanisms to survive antimicrobial exposure, a process accelerated by misuse and overuse of antibiotics in human medicine, agriculture, and veterinary settings. Bacterial resistance poses the greatest immediate concern, contributing to an estimated 1.27 million deaths in 2019 and nearly 5 million deaths associated with resistant infections worldwide. Without urgent intervention, Projections suggest that AMR could cause up to 10 million deaths annually by 2050, potentially surpassing cancer as a leading cause of mortality although these estimates remain subject to uncertainty. This review examines key biological mechanisms of resistance, including enzymatic degradation, target modification, efflux pumps, porin loss, and horizontal gene transfer. It highlights global hotspots and emerging resistance determinants such as NDM-1 and mcr-1, as well as antibiotic usage trends across human and animal sectors. Unlike acute pandemics such as COVID-19, AMR progresses silently but persistently, earning recognition as a "slow pandemic." Its spread involves interconnected human, animal, and environmental reservoirs, necessitating a One Health approach. The review also summarizes current global responses, including the WHO Global Action Plan, surveillance platforms such as GLASS, and ECDC, and research initiatives like CARB-X and GARDP. Despite progress, significant gaps remain in policy, surveillance, and antimicrobial stewardship, particularly in low- and middle-income countries, underscoring the urgent need for coordinated multisectoral action. However, the conclusions drawn are limited by variability in global surveillance data, differences in reporting standards, and reliance on previously published studies, which may not fully capture regional disparities.},
}

Humans
Animals
*Anti-Bacterial Agents/pharmacology/therapeutic use
*Drug Resistance, Bacterial/genetics
*One Health
*Bacteria/drug effects/genetics
Global Health
Gene Transfer, Horizontal
Bacterial Infections/microbiology/drug therapy
Drug Resistance, Multiple, Bacterial

@article {pmid42320742,
year = {2026},
author = {Lin, L and Sun, X and Gao, Y},
title = {Whole genome sequencing of carbapenem- and polymyxin-resistant clinical isolates of Escherichia coli to analyze resistance mechanisms.},
journal = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases},
volume = {143},
number = {},
pages = {105971},
doi = {10.1016/j.meegid.2026.105971},
pmid = {42320742},
issn = {1567-7257},
abstract = {OBJECTIVES: To clarify the resistance phenotypes, genetic and molecular characteristics of carbapenem-polymyxin co-resistant Escherichia coli clinical isolates in China, and provide evidence for clinical infection control.

METHODS: 11 co-resistant E. coli isolates collected from a hospital during 2021-2023 were analyzed retrospectively. Antimicrobial susceptibility testing, modified carbapenem inactivation method (mCIM/eCIM) and whole-genome sequencing (WGS) were performed. Resistance genes, plasmid replicons, multilocus sequence typing (MLST) and phylogenetic analysis based on core genome SNPs were conducted using bioinformatics tools.

RESULTS: All isolates co-carried blaNDM and mcr-1 genes, with blaNDM-5 (72.7%) as the dominant variant. Heterogeneous plasmid replicon types were detected, and phylogenetic analysis clustered the isolates into three clades. MLST identified seven sequence types (STs), with ST167 (36.4%) being the most prevalent. All isolates were resistant to carbapenems, polymyxins and β-lactams, and universally susceptible to tigecycline.

CONCLUSIONS: The coexistence of blaNDM and mcr-1 is the key cause of carbapenem-polymyxin co-resistance in E. coli. The diverse plasmid replicon types and typical resistance gene profiles highly suggest the potential involvement of plasmid-mediated horizontal gene transfer in resistance gene dissemination, which warrants further experimental verification. The genetic diversity of the isolates indicates no clonal outbreak, but the presence of closely related strains highlights the need for continuous surveillance and strengthened infection control measures to prevent further spread of such multidrug-resistant strains.},
}

@article {pmid42321988,
year = {2026},
author = {Korsah, S and Ofori, M and Aboagyewaah, MO and Geoffrey, K and Boateng, MO and Korsah, J and Tagoe, M and Ninkyi, T and Danquah, CA},
title = {Exploring the In Vitro Antibacterial Properties of Milicia regia and Entandrophragma angolensis: Insight Into Their Antibiofilm and Efflux Pump Inhibitory Activities.},
journal = {TheScientificWorldJournal},
volume = {2026},
number = {1},
pages = {e2641156},
pmid = {42321988},
issn = {1537-744X},
mesh = {*Biofilms/drug effects ; *Plant Extracts/pharmacology/chemistry ; *Anti-Bacterial Agents/pharmacology/chemistry ; Microbial Sensitivity Tests ; Plant Bark/chemistry ; Staphylococcus aureus/drug effects ; },
abstract = {INTRODUCTION: Biofilms are breeding grounds for adapted and acquired antibiotic resistance through increased efflux activities and horizontal gene transfer. Medicinal plants are sources of antimicrobial agents for the treatment of bacterial, parasitic, and fungal infections.

AIM: In this research, we examined antimicrobial, antibiofilm, and efflux pump inhibition activity of the methanolic extracts of the stem barks of Milicia regia and Entandrophragma angolensis.

METHODS: Crude methanolic extracts were assessed using three distinct assays: the high-throughput spot culture growth inhibition (HT-SPOTi) assay for bacterial growth inhibition, a crystal violet-based antibiofilm screening assay to quantify their biofilm‑inhibitory activity and the ethidium bromide accumulation assay for evaluating changes in bacterial cell membrane permeability against Mycobacterium smegmatis, Mycobacterium aurum, Staphylococcus aureus, and Pseudomonas aeruginosa.

RESULTS: The preliminary qualitative phytochemical screening suggested the presence of tannins, flavonoids, terpenoids, glycosides, alkaloids, and saponins. The minimum inhibitory concentrations for extracts against S. aureus, P. aeruginosa, M. aurum, and M. smegmatis were 250, 125, 500, and 250 μg/mL, respectively, and for E. angolensis: 125, 125, 500, and 500 μg/mL, respectively. Both plants displayed significant (∗∗∗ρ < 0.005) biofilm inhibition activities against all bacteria with the highest inhibition recorded in S. aureus: M. regia, E. angolensis, and the reference drug ciprofloxacin were 73%, 62%, and 79%, respectively.

CONCLUSION: The extracts produced marked antiefflux pump effects against S.aureus and P. aeruginosa. This study established the antibacterial, antibiofilm, and efflux pump inhibitory capacities of M. regia and E. angolensis and provides the rationale for their folkloric uses in the treatment of infections.},
}

*Biofilms/drug effects
*Plant Extracts/pharmacology/chemistry
*Anti-Bacterial Agents/pharmacology/chemistry
Microbial Sensitivity Tests
Plant Bark/chemistry
Staphylococcus aureus/drug effects

@article {pmid42322430,
year = {2026},
author = {Kumru, S},
title = {Comparative Genomic Analysis of Pseudomonas shahriarae Reveals Virulence Potential, Antimicrobial Resistance, and Environmental Adaptation.},
journal = {Current microbiology},
volume = {83},
number = {8},
pages = {},
pmid = {42322430},
issn = {1432-0991},
mesh = {*Pseudomonas/genetics/drug effects/pathogenicity/classification/physiology/isolation & purification ; Animals ; *Genome, Bacterial ; Virulence ; *Drug Resistance, Bacterial ; Virulence Factors/genetics ; Phylogeny ; Anti-Bacterial Agents/pharmacology ; Genomics ; Fishes/microbiology ; *Adaptation, Physiological ; Fish Diseases/microbiology ; *Pseudomonas Infections/microbiology/veterinary ; },
abstract = {Pseudomonas shahriarae is a recently identified member of the P. fluorescens group. Its ecological range and ability to cause disease are still mostly unknown, especially in aquaculture settings. This work presents the first genome sequence of P. shahriarae isolated from diseased Siberian sturgeon (Acipenser baerii). To obtain deeper understanding of its evolutionary history, pathogenicity, and capacity of antibiotic resistance, this genome was compared with seven other publicly available genomes. The draft genome of strain SK21 was 6.12 Mb size and had a GC content of 60.5%. Core genome analysis revealed 3,652 conserved genes among strains, and average nucleotide identity values over 98% validated species-level relatedness among the majority of isolates. One strain that was originally thought to be P. shahriarae exhibited only about 83% ANI and grouped with Pseudomonas iridis, which suggests that it was misclassified. A comparative genomic investigation showed that there is a shared set of virulence-associated factors, such as genes that help with adhesion, biofilm formation, motility, immunological regulation, and nutrition acquisition, as well as different secretion systems (T1SS-T6SS). The strain from sturgeon uniquely expressed a full class 1 integron, indicating the acquisition of antimicrobial resistance components by horizontal gene transfer in aquaculture settings. The extensive prophage regions and metabolic flexibility further underscore the adaptability of this species. This work presents the first genomic evidence associating P. shahriarae with sturgeon disease and uncovers a genetically varied bacteria that may impact aquaculture health and the spread of antibiotic resistance.},
}

*Pseudomonas/genetics/drug effects/pathogenicity/classification/physiology/isolation & purification
Animals
*Genome, Bacterial
Virulence
*Drug Resistance, Bacterial
Virulence Factors/genetics
Phylogeny
Anti-Bacterial Agents/pharmacology
Genomics
Fishes/microbiology
*Adaptation, Physiological
Fish Diseases/microbiology
*Pseudomonas Infections/microbiology/veterinary

@article {pmid42325637,
year = {2026},
author = {Adegoke, SC and Karim, MA and Jr, MC and Yao Yawlui, IS and LaJeunesse, D},
title = {Advancements in Technologies Targeting Horizontal Gene Transfer(?)Routes to Control Drug Resistance Evolution.},
journal = {ACS bio & med chem Au},
volume = {6},
number = {3},
pages = {210-236},
pmid = {42325637},
issn = {2694-2437},
abstract = {The global rise of multidrug-resistant (MDR) bacteria poses a major public health crisis, threatening the effectiveness of modern medicine. Traditional antibiotic development struggles to keep pace with bacterial evolution, largely due to the rapid dissemination of antibiotic resistance genes via horizontal gene transfer (HGT). HGT mechanisms both canonical and noncanonical enable bacteria to acquire resistance traits defining species and even special challenges. In this review, we cover the current understanding of HGT in spreading antibiotic resistance and explore possible strategies to control HGT and slow the spread of antimicrobial resistance. Recent advances highlight the potential of synthetic competence inhibitors, advanced oxidation processes (AOPs), CRISPR-Cas technologies, gene drives, and antiplasmids to disrupt horizontal gene flow and mitigate resistance evolution. Despite promising laboratory results, challenges remain in translating these approaches into clinical and environmental applications. Blocking HGT could complement antimicrobial stewardship programs and traditional antibiotic therapies by curbing the emergence of new resistant strains at their genetic roots. By targeting the foundational mechanisms of resistance acquisition, these strategies offer a proactive pathway to extend the efficacy of existing antibiotics and prevent a "postantibiotic" era. Ongoing research into bacterial pathogenesis, genome defense systems, and innovative gene-editing technologies will be critical to developing effective, scalable solutions for managing MDR infections worldwide.},
}

@article {pmid41853961,
year = {2026},
author = {Wan, L and Li, X and Zheng, X and Chen, T and Yang, Y and Chen, Y and Liu, X and Wang, C},
title = {Genomic insights into the tmexCD-toprJ: plasmid-mediated evolution, dissemination and diversity in bacterial populations.},
journal = {The Journal of antimicrobial chemotherapy},
volume = {81},
number = {4},
pages = {},
doi = {10.1093/jac/dkag107},
pmid = {41853961},
issn = {1460-2091},
support = {31900151//National Natural Science Foundation of China/ ; },
mesh = {*Plasmids/genetics ; *Evolution, Molecular ; *Genetic Variation ; Humans ; Pseudomonas aeruginosa/genetics/drug effects ; Genomics ; Anti-Bacterial Agents/pharmacology ; Animals ; Klebsiella pneumoniae/genetics/drug effects ; Drug Resistance, Bacterial/genetics ; Genome, Bacterial ; *Bacteria/genetics/drug effects/classification ; Bacterial Proteins/genetics ; Computational Biology ; Gene Transfer, Horizontal ; beta-Lactamases/genetics ; Klebsiella ; },
abstract = {BACKGROUND: The plasmid-mediated tigecycline resistance gene tmexCD-toprJ has emerged in clinical and animal isolates, but its epidemiological spread and plasmid adaptation mechanisms remain unclear.

METHODS: We characterized tmexCD-toprJ-carrying plasmids from the PLSDB database through comprehensive bioinformatic analyses, revealing their genetic features and potential inter-species transmission routes.

RESULTS: Genomic analysis of 197 tmexCD-toprJ-carrying plasmids revealed significant backbone diversity, clustering into 18 groups and 12 singletons. The 30 identified host species were predominantly Klebsiella pneumoniae (K. pneumoniae) (53.3%), followed by Pseudomonas aeruginosa (P. aeruginosa) (16.8%) and Klebsiella quasipneumoniae (K. quasipneumoniae) (4.1%). MOB-suite typing classified 53.8% as conjugative, 5.6% mobilizable and 40.61% non-mobilizable. Over half of the tmexCD-toprJ-carrying plasmids were predicted to contain the MOBH family. Among the identified variants, tmexCD1-toprJ1, tmexCD2-toprJ2 and tmexCD3-toprJ1 representing the predominant forms. TmexCD1-toprJ1 was linked to IncFIB/IncHI1B/rep_cluster_1254 plasmids, while tmexCD2-toprJ2 associated with diverse replicons, enabling cross-species spread. A total of 14 plasmids co-localized tmexCD-toprJ with carbapenemase (blaNDM/KPC) and mcr genes, forming high-risk resistance platforms. Notably, a 36 483 bp insertion in IncP/rep_cluster_1115 plasmids disrupted tmexC6D6-toprJ1b and carried heavy metal resistance genes.

CONCLUSIONS: These findings enhance our understanding of the diversity of tmexCD-toprJ-carrying plasmids. The convergence of tmexCD-toprJ with carbapenemase and polymyxin resistance genes in clinically prevalent plasmids underscores an urgent need for enhanced surveillance targeting complete genetic environments.},
}

*Plasmids/genetics
*Evolution, Molecular
*Genetic Variation
Humans
Pseudomonas aeruginosa/genetics/drug effects
Genomics
Anti-Bacterial Agents/pharmacology
Animals
Klebsiella pneumoniae/genetics/drug effects
Drug Resistance, Bacterial/genetics
Genome, Bacterial
*Bacteria/genetics/drug effects/classification
Bacterial Proteins/genetics
Computational Biology
Gene Transfer, Horizontal
beta-Lactamases/genetics
Klebsiella

@article {pmid41878261,
year = {2026},
author = {Wang, M and Han, C and Hao, M and Zhang, W and Wang, S},
title = {Carbapenem-resistant Salmonella Derby harboring a plasmid carrying bla NDM-1 from a clinical case in China.},
journal = {Frontiers in cellular and infection microbiology},
volume = {16},
number = {},
pages = {1765519},
pmid = {41878261},
issn = {2235-2988},
mesh = {*Plasmids/genetics ; *beta-Lactamases/genetics ; Humans ; China ; *Carbapenems/pharmacology ; Microbial Sensitivity Tests ; *Salmonella Infections/microbiology ; Anti-Bacterial Agents/pharmacology ; *Salmonella enterica/genetics/drug effects/isolation & purification/classification ; Whole Genome Sequencing ; Electrophoresis, Gel, Pulsed-Field ; Conjugation, Genetic ; Gene Transfer, Horizontal ; Bacterial Proteins/genetics ; },
abstract = {OBJECTIVE: The increasing antimicrobial resistance in non-typhoidal Salmonella (NTS) poses a growing challenge to clinical therapy. This study reports, for the first time, a carbapenem-resistant Salmonella enterica serovar Derby isolate. Although serovar Derby accounts for a relatively small proportion of clinical NTS infections, elucidating the mechanism, origin, and dissemination potential of its carbapenem resistance is crucial for enhancing surveillance and prevention strategies against resistant NTS.

METHODS: Antimicrobial susceptibility testing was performed using commercial broth microdilution panels with the Beckman Coulter WalkAway 96 PLUS system. Whole-genome sequencing (WGS) and S1-pulsed-field gel electrophoresis (PFGE) were employed to characterize the chromosomes and plasmids of isolates. Conjugation assays were conducted to evaluate plasmid mobility. Additionally, the NCBI Genome and Pathogens databases were used to identify carbapenemase-producing Salmonella strains.

RESULTS: A patient with aplastic anemia was admitted with abdominal pain and received successive treatments. During periods of recurrent fever, carbapenem-resistant S. Derby (CS_CRSA) and Escherichia coli (CS_CREco) were isolated from rectal swabs. WGS revealed that both strains carried a nearly identical IncFII plasmid (80,195/80,198 bp) harboring bla NDM-1 and qnrS1 genes. This plasmid contained a complete conjugation module, and could be transferred from CS_CRSA and CS_CREco to the recipient at efficiencies of (4.50 ± 1.29)×10[-2] and (3.17 ± 0.74)×10[-1]. Comparative analysis showed its high similarity to a resistance plasmid of Salmonella enterica serovar Typhimurium isolated from Zhejiang, China. As of June 25, 2025, 35 fully assembled Salmonella enterica strains carrying carbapenemase genes were identified, predominantly S. Typhimurium and its variants. Phylogenetic analysis indicated that most carbapenemase-producing Salmonella (CPSA) strains were scattered, while clonal dissemination was observed in some serotypes.

CONCLUSION: This study reports a clinical isolate of carbapenem-resistant S. Derby, likely resulting from horizontal transfer of a bla NDM-1 -carrying plasmid, which indicates that carbapenem resistance is extending to less common and low virulence serovars of Salmonella. The emergence of such strains poses a challenge to patient care, especially for immunocompromised populations suffering from invasive infections. Additionally, clonal dissemination of CPSA in certain serotypes warrants heightened vigilance and preventive measures.},
}

*Plasmids/genetics
*beta-Lactamases/genetics
Humans
China
*Carbapenems/pharmacology
Microbial Sensitivity Tests
*Salmonella Infections/microbiology
Anti-Bacterial Agents/pharmacology
*Salmonella enterica/genetics/drug effects/isolation & purification/classification
Whole Genome Sequencing
Electrophoresis, Gel, Pulsed-Field
Conjugation, Genetic
Gene Transfer, Horizontal
Bacterial Proteins/genetics

@article {pmid41936759,
year = {2026},
author = {Guo, D and Yuan, C and Zhang, C and Zheng, M and Wang, G and Liu, L and Chen, G},
title = {Chlorination promotes antibiotic resistance dissemination via conjugative transfer and stress response in reclaimed water.},
journal = {Journal of environmental management},
volume = {404},
number = {},
pages = {129588},
doi = {10.1016/j.jenvman.2026.129588},
pmid = {41936759},
issn = {1095-8630},
mesh = {*Halogenation ; *Drug Resistance, Microbial/genetics ; *Drug Resistance, Bacterial/genetics ; Gene Transfer, Horizontal ; *Wastewater/microbiology ; Bacteria/genetics/drug effects ; Water Purification ; Anti-Bacterial Agents/pharmacology ; },
abstract = {Chlorination is widely applied in municipal wastewater treatment for pathogen inactivation; however, it may inadvertently induce bacterial stress responses and promote the spread of antibiotic resistance genes (ARGs), posing potential environmental risks. The mechanisms underlying chlorination-enhanced horizontal ARG transfer in reclaimed water remain unclear. To address this knowledge gap, we investigated resistance evolution and horizontal transfer in reclaimed water following chlorination. Chlorination (0.5-5.0 mg/L) increased the absolute abundance of antibiotic-resistant bacteria by 1.38-4.93 log units during regrowth. At 3.0 mg/L chlorine with a 3-day regrowth, the bacterial community was profoundly reshaped, with dominant phyla shifting from Proteobacteria, Patescibacteria, and Bacteroidota in the control to a predominance of Proteobacteria (96.31%). Sul1 expression was upregulated 9.95-fold and ARG conjugative transfer increased by 13.2-fold. These changes were accompanied by significant upregulation of genes associated with resistance spread and stress responses, including efflux pump genes (acrD, ermA, tolC), outer membrane protein gene (ompA), and dormancy regulator gene (rpoS). Collectively, these findings demonstrate that sub-lethal chlorination facilitates ARG dissemination in reclaimed water by inducing bacterial stress responses and conjugation, highlighting the need for optimized disinfection strategies to reduce the environmental spread of antibiotic resistance.},
}

*Halogenation
*Drug Resistance, Microbial/genetics
*Drug Resistance, Bacterial/genetics
Gene Transfer, Horizontal
*Wastewater/microbiology
Bacteria/genetics/drug effects
Water Purification
Anti-Bacterial Agents/pharmacology

@article {pmid41841430,
year = {2026},
author = {Beh, JQ and Howden, BP and Webb, JR and Connor, CH},
title = {Global dissemination of optrA-mediated linezolid resistance in enterococci.},
journal = {The Journal of antimicrobial chemotherapy},
volume = {81},
number = {4},
pages = {},
pmid = {41841430},
issn = {1460-2091},
support = {//National Health and Medical Research Council/ ; },
mesh = {Plasmids/analysis ; *Enterococcus faecium/genetics/drug effects ; *Enterococcus faecalis/genetics/drug effects ; *Anti-Bacterial Agents/pharmacology ; *Drug Resistance, Bacterial ; DNA Transposable Elements ; *Linezolid/pharmacology ; Humans ; Gene Transfer, Horizontal ; Extrachromosomal DNA ; Genome, Bacterial ; },
abstract = {OBJECTIVES: Acquired resistance to last-line linezolid has emerged in Enterococcus spp. and can be conferred by the optrA gene. Here, we study the global genomic context of optrA in E. faecalis and E. faecium, to understand its dissemination pattern.

METHODS: We identified 565 enterococcal genomes from NCBI and 86 optrA-containing enterococcal plasmids from the plasmid database, PLSDB. We characterized the plasmid replication and antimicrobial resistance genes of optrA-containing plasmids and the plasmid pangenome. To identify prevalent optrA genetic contexts, we mapped the genomes against PLSDB plasmid and transposon Tn6674 (prevalent in E. faecalis) sequences using minimap2.

RESULTS: A greater proportion of E. faecium (47.3%: n = 70/149) carried the optrA gene on plasmids than E. faecalis (28.9%: n = 120/416). In E. faecalis, the major optrA contexts were represented either by a Tn6674 transposon (28.0%) or a plasmid-associated MDR fexA-optrA-erm(A) genetic unit (32.9%), and were associated with distinct E. faecalis phylogroups. In E. faecium, the dominant optrA contexts were the optrA-erm(A)/(B) genetic unit (24.2%), the fexA-optrA-erm(A) unit (16.8%), and the Tn6261 transposon (14.1%). We observed that in some E. faecalis and E. faecium plasmids, the fexA-optrA-erm(A) unit was flanked by IS1216E elements on both sides, suggesting the mobilization of this MDR gene cassette by IS1216E-like elements into diverse plasmid backgrounds.

CONCLUSIONS: This is the first study to investigate the genomic context of optrA in a phylogeographically diverse enterococcal genome collection. We demonstrated that mobile genetic elements play a key role in the global expansion of optrA and highlighted the underlying public health concern imposed by plasmids in drug-resistant enterococcal dissemination.},
}

Plasmids/analysis
*Enterococcus faecium/genetics/drug effects
*Enterococcus faecalis/genetics/drug effects
*Anti-Bacterial Agents/pharmacology
*Drug Resistance, Bacterial
DNA Transposable Elements
*Linezolid/pharmacology
Humans
Gene Transfer, Horizontal
Extrachromosomal DNA
Genome, Bacterial

@article {pmid42317762,
year = {2026},
author = {Joshi, G and Rani, S and Bharti, D and Panda, N and Chavan, P and Mathpal, S and Ramaiah, S and Anbarasu, A},
title = {The role of the gut microbiome in antibiotic-driven antimicrobial resistance.},
journal = {Frontiers in microbiology},
volume = {17},
number = {},
pages = {1856738},
pmid = {42317762},
issn = {1664-302X},
abstract = {Antimicrobial resistance (AMR) is one of the most pressing threats to global health system. The human gut harbors a complex microbial ecosystem coordinated through mechanisms of metabolic interdependence. The gut microbiota plays a vital role in normal growth and physiological processes of the human body. It serves both as a target of antibiotic-mediated disruption and as a reservoir for the propagation of antimicrobial resistance genes. Although antibiotics remain indispensable for the treatment of bacterial infections, their broad ecological impact on the gut microbiota can undermine the microbial balance that protects the host against pathogen invasion and metabolic dysfunction. The gut microbiome also functions as a reservoir of antimicrobial resistance genes collectively termed the "resistome," which can be mobilised and transferred between commensal and pathogenic bacteria via horizontal gene transfer mechanisms such as conjugation, transformation, and transduction. This review examines the composition and functions of the human gut microbiota, the mechanism of antibiotic-induced gut dysbiosis, and the role of host factors like age, genetics, diet and immune status, on microbiome dynamics and AMR development. We further evaluate emerging methods for resistome characterisation, which include PCR, next-generation sequencing, functional metagenomics and artificial intelligence-driven tools. Finally, we discuss microbiome-targeted therapeutic strategies such as faecal microbiota transplantation (FMT), phage therapy, CRISPR-based therapies, and antimicrobial peptides for combating AMR and restoring gut microbial homeostasis. Overall, this review highlights that maintaining and re-establishing the integrity of the gut microbiome should be considered a fundamental component of antimicrobial stewardship strategies aimed at controlling AMR worldwide.},
}

@article {pmid42313334,
year = {2026},
author = {Fallah Vosoughi, A and Foroohi, F and Ahmadi, S and Shirzadian, M and Golpasand, T and Behzadi, P},
title = {Distribution of mrk genes among uopathogenic Klebsiella pneumoniae.},
journal = {Journal of applied genetics},
volume = {},
number = {},
pages = {},
pmid = {42313334},
issn = {2190-3883},
abstract = {The mrk operon gene clusters encode type 3 fimbriae, involving in biofilm formation. Hence, we aimed to find out the distribution of mrk genes among uropathogenic Klebsiella pneumoniae (UPKP) strains. Moreover, mrk genes, hypermucoviscosity (HMV) characteristic and antimicrobial resistance (AMR) patterns and profiles were successfully, provided. From August 2023 to January 2024, 104 positive urine samples were collected. Standard microbiological and biochemical tests were employed to confirm the UPKP strains. Kirby-Bauer disc diffusion method was recruited to conduct antimicrobial susceptibility test (AST). The HMV characteristic in UPKP isolates was assessed using the string test. Finally, multiplex polymerase chain reaction (mPCR) was used to identify mrk genes distribution. Chi-square (χ[2]) and Fisher's exact tests were utilized for statistical analysis. The mrk gene distribution varied among the UPKP isolates comprising mrkA (1.92%), mrkB (0.00%), mrkC (5.77%), mrkD (23.08%), mrkE (37.50%), and mrkF (83.65%). No mrk genes were detected among 13.46% (14/104) of UPKP isolates. The most common mrk gene patterns involved mrkF (32.70%), mrkE-mrkF (25.00%), and mrkD-mrkF (11.54%). In addition, the isolates exhibited diverse AMR profiles and phenotypes including: 65 multi-drug resistant (MDR) strains (nine groups, 42 patterns), 13 extensively drug-resistant (XDR) strains (nine patterns), nine pan drug-resistant (PDR) strains, 23 ESBL producers, and nine HMV isolates. None of the HMV strains displayed XDR, PDR, or ESBL phenotypes, suggesting limited horizontal gene transfer (HGT). Detailed analysis of mrk genes and AMR characteristics in UPKP, provides essential information for selecting effective prevention protocols and treatments for urinary tract infections (UTIs) and combating AMR.},
}

@article {pmid42313452,
year = {2026},
author = {Sagen, AS and Shawrob, KSM and Salvadori, G and Junges, R},
title = {Genetic and functional characterization of the natural transformation system in Streptococcus constellatus.},
journal = {Microbiology (Reading, England)},
volume = {172},
number = {6},
pages = {},
pmid = {42313452},
issn = {1465-2080},
mesh = {*Transformation, Bacterial ; Bacterial Proteins/genetics/metabolism ; Gene Expression Regulation, Bacterial ; *Streptococcus constellatus/genetics/metabolism/drug effects ; *DNA Transformation Competence ; Bacteriocins/metabolism ; Regulon ; Operon ; Genome, Bacterial ; },
abstract = {Streptococcus constellatus is an opportunistic pathogen frequently associated with abscess formation in various body sites. While the species has been shown to acquire exogenous DNA through natural transformation, functional analyses of its underlying mechanisms and optimized genetic editing protocols remain limited. Thus, our aim was to characterize the natural transformation system in S. constellatus and investigate environmental factors coordinating its activation. In addition, we sought to develop an optimized protocol for genome editing. Genomic analysis revealed that 73% of analyzed strains possess orthologs for essential competence regulon genes, with 58% harboring both a complete ComCDE-based operon and the putative transformation machinery required for natural competence. While all complete genomes harbored three copies of the master regulator sigX, the accessory regulator comW was seemingly absent. Lacking the peptide exporter comAB, we demonstrated that S. constellatus utilizes the bacteriocin transporter silED for competence-stimulating peptide export. Gene expression assays indicated system activation at peptide concentrations as low as 4 nM, with peak sigX expression obtained over 60 nM. With the goal of optimizing gene editing strategies, we developed a protocol utilizing rich media supplemented with BSA and calcium chloride, significantly increasing transformation frequencies. Furthermore, we observed that environmental stressors can upregulate the system, including hydrogen peroxide and subinhibitory concentrations of the antibiotics erythromycin, chloramphenicol and ampicillin. Given the increasing clinical relevance of the anginosus group, elucidating horizontal gene transfer mechanisms can provide critical insights into the evolutionary process and pathogenic potential of these species.},
}

*Transformation, Bacterial
Bacterial Proteins/genetics/metabolism
Gene Expression Regulation, Bacterial
*Streptococcus constellatus/genetics/metabolism/drug effects
*DNA Transformation Competence
Bacteriocins/metabolism
Regulon
Operon
Genome, Bacterial

@article {pmid42315032,
year = {2026},
author = {Thomé, MLFL and Kashiwaqui, NY and Ferreira, MA and Zapata, AMM and Rodero, CF and Zucolotto, V and Bidoia, DL and Sumini, M and Santos, MHM and Endo, TH and de Lima, BM and Montini, VH and Filho, PP and Nakazato, G and Kobayashi, RKT},
title = {Comparative methodological study of ultracentrifugation and a commercial kit for the isolation and characterization of outer membrane vesicles from Burkholderia thailandensis.},
journal = {Journal of microbiological methods},
volume = {},
number = {},
pages = {107588},
doi = {10.1016/j.mimet.2026.107588},
pmid = {42315032},
issn = {1872-8359},
abstract = {Outer Membrane Vesicles (OMVs) are nanostructures naturally produced by Gram-negative bacteria, playing a relevant role in processes such as horizontal gene transfer, quorum sensing modulation, antibacterial and antibiofilm activity, and presenting potential applications in nanotechnology, including drug delivery systems. Considering the diversity of methods employed for their isolation and purification, this study aimed to compare the morphological characteristics, overall composition, concentration, and potential cytotoxic effects of OMVs isolated by ultracentrifugation (OMVs-UC) and by a commercial exosome isolation kit (OMVs-Kit). To the best of our knowledge, this is the first study to provide a systematic comparison between ultracentrifugation and a commercial precipitation-based kit for OMV isolation in Burkholderia thailandensis, integrating multiple analytical approaches to evaluate how the isolation method affects vesicle characteristics. The results indicated that the kit offers greater operational simplicity, enabling the recovery of OMVs with morphological patterns and composition similar to those obtained by ultracentrifugation. The concentrations obtained were 7.08 × 10[8] particles/mL for OMVs-UC and 2.46 × 10[8] particles/mL for OMVs-Kit, with mean diameters of 249 nm and 145.8 nm, respectively, according to Nanoparticle Tracking Analysis (NTA). Despite minor variations attributed to the distinct isolation and purification processes, the composition of OMVs was predominantly similar between methods. Furthermore, OMVs obtained by both approaches did not exhibit cytotoxic effects in VERO CCL-81 cells, reinforcing their potential for biotechnological applications. Overall, the commercial kit represents a viable alternative to ultracentrifugation, allowing faster and simplified OMV isolation while maintaining comparable vesicle characteristics.},
}

@article {pmid42315490,
year = {2026},
author = {Morohoshi, T and Ueno, K and Someya, N},
title = {Multi-copy aiiA genes encoding quorum-quenching enzymes in Bacillus thuringiensis: identification and functional characterization of the novel AHL-lactonase, AiiA2.},
journal = {FEMS microbiology letters},
volume = {},
number = {},
pages = {},
doi = {10.1093/femsle/fnag073},
pmid = {42315490},
issn = {1574-6968},
abstract = {Quorum sensing mediated by N-acylhomoserine lactones (AHLs) plays a key role in the regulation of virulence in many plant-pathogenic bacteria, and enzymatic degradation of AHLs represents a promising biocontrol strategy known as quorum quenching. The AHL lactonase gene aiiA is widely distributed within the genus Bacillus and is generally considered to be present as a single-copy gene. In this study, we show that specific strains of Bacillus thuringiensis harbor two distinct aiiA homologs. Genome analyses of environmental B. thuringiensis isolates, together with publicly available genome sequences, revealed a phylogenetically distinct aiiA homolog in addition to the canonical gene. Phylogenetic analysis classified these homologs into two groups, designated AiiA1 and AiiA2. Comparative genomic analysis indicated that aiiA2 is located within variable genomic regions, suggesting acquisition via horizontal gene transfer through mechanisms other than transposon-mediated transposition. Functional assays confirmed that both AiiA1 and AiiA2 possess AHL-degrading activity. Quantitative analyses showed that the specific activities of both enzymes increased with increasing temperature, and although AiiA2 exhibited slightly higher activity than AiiA1 across the tested temperature range, no dramatic difference in AHL-degrading activity was observed between the two enzymes. These findings highlight previously unrecognized diversity in quorum-quenching systems within B. thuringiensis and suggest that the coexistence of multiple AHL lactonases with largely comparable activities may contribute to a flexible and robust quorum-quenching capacity in plant-associated environments.},
}

@article {pmid42315631,
year = {2026},
author = {Bejes, BM and Vicari, MR and Nogaroto, V and Bail, L and Arend, LNVS and da Silva Nogueira, K and Pileggi, SAV and Tuon, FF and Ito, CAS and Olchanheski, LR and Pileggi, M},
title = {Genomic and Phenotypic Insights into Carbapenemase-Mediated Resistance and Clonal Diversity of Pseudomonas aeruginosa Clinical Isolates from Southern Brazil.},
journal = {Current microbiology},
volume = {83},
number = {8},
pages = {},
pmid = {42315631},
issn = {1432-0991},
mesh = {*beta-Lactamases/genetics/metabolism ; *Pseudomonas aeruginosa/genetics/drug effects/isolation & purification/enzymology/classification ; Brazil/epidemiology ; *Pseudomonas Infections/microbiology ; Humans ; *Bacterial Proteins/genetics/metabolism ; Anti-Bacterial Agents/pharmacology ; Multilocus Sequence Typing ; Drug Resistance, Multiple, Bacterial/genetics ; Microbial Sensitivity Tests ; Plasmids/genetics ; Genetic Variation ; Phenotype ; Carbapenems/pharmacology ; Genomics ; },
abstract = {Pseudomonas aeruginosa is a major opportunistic pathogen associated with high morbidity in hospitalized patients due to its intrinsic and acquired resistance mechanisms. Carbapenem resistance, often mediated by the production of carbapenemase, poses a critical therapeutic challenge worldwide. This study investigated the genomic organization, molecular diversity, and plasmid-mediated dissemination of carbapenemase genes in P. aeruginosa isolates from hospitals in Paraná and Santa Catarina, Brazil, and explored their correlation with phenotypic resistance profiles. Eight isolates (80%) were classified as extensively drug-resistant (XDR), showing broad resistance to β-lactams, carbapenems, and β-lactam/β-lactamase inhibitor combinations. Multi-Locus Sequence Typing revealed a heterogeneous clonal structure, with ST1560 being the predominant type (30%). Multiple β-lactamase genes were identified, including chromosomal blaPDC variants, blaOXA-50, and carbapenemase genes blaSPM-1, blaIMP-16, blaIMP-1, blaVIM-2, blaKPC-2, and blaNDM-1. Notably, 40% of isolates carried plasmid-borne carbapenemase genes, indicating a potential for horizontal gene transfer. Isolate 20,783 exhibited high resistance despite lacking additional carbapenemase genes, suggesting alternative mechanisms such as efflux or porin loss. The predominance of XDR P. aeruginosa,which harbors diverse carbapenemases, including plasmid-mediated determinants, underscores the complexity of antimicrobial resistance in Brazilian hospitals. The coexistence of multiple resistance mechanisms, coupled with clonal heterogeneity, highlights the urgent need for integrated genomic surveillance and targeted infection control strategies to mitigate the spread of multidrug-resistant P. aeruginosa in clinical settings.},
}

*beta-Lactamases/genetics/metabolism
*Pseudomonas aeruginosa/genetics/drug effects/isolation & purification/enzymology/classification
Brazil/epidemiology
*Pseudomonas Infections/microbiology
Humans
*Bacterial Proteins/genetics/metabolism
Anti-Bacterial Agents/pharmacology
Multilocus Sequence Typing
Drug Resistance, Multiple, Bacterial/genetics
Microbial Sensitivity Tests
Plasmids/genetics
Genetic Variation
Phenotype
Carbapenems/pharmacology
Genomics

@article {pmid42308119,
year = {2026},
author = {Holman, DB and Gzyl, KE and Kommadath, A and Määttänen, P},
title = {Multi-omic characterization of the sow colostrum and milk microbiome and proteome.},
journal = {Microbial genomics},
volume = {12},
number = {6},
pages = {},
doi = {10.1099/mgen.0.001726},
pmid = {42308119},
issn = {2057-5858},
mesh = {Animals ; *Colostrum/microbiology ; *Milk/microbiology ; Female ; *Proteome/genetics ; Multiomics ; *Microbiota/genetics ; Swine ; *Bacteria/classification/isolation & purification/genetics ; Metagenomics/methods ; Proteomics ; },
abstract = {Sow colostrum and milk provide essential nutrients, immune protection and one of the earliest microbial exposures for piglets. However, the microbial composition, functional potential and host interactions of these mammary secretions remain poorly characterized. Here, we combined culturomics, metagenomics and proteomics to comprehensively characterize the microbiome and proteome of sow colostrum and milk collected at farrowing and at 7 and 21 days postpartum. We recovered 132 bacterial isolates representing at least 42 species, including 15 putatively novel taxa. These isolates included both potentially pathogenic species, such as Sarcina perfringens and Streptococcus suis, and potentially beneficial bacterial species like Lactobacillus amylovorus and Lactiplantibacillus plantarum. The microbial composition and functional potential shifted significantly as the milk matured, with L. amylovorus, Limosilactobacillus reuteri and Rothia spp. among the most relatively abundant taxa. Several antimicrobial resistance genes, including erm(C), tet(K), tet(M), lnu(A), poxtA and fexB, were identified on contigs encoding plasmid replicons in the isolates, indicating potential for horizontal gene transfer. Functional annotation of isolate genomes indicated broad carbohydrate-active enzyme (CAZyme) repertoires, including β-galactosidase-associated families and other CAZyme families consistent with potential milk oligosaccharide utilization. The colostrum and milk proteome also shifted during lactation, reflecting declining immune-related proteins and increasing metabolic and structural proteins. Correlations between specific microbial taxa and host proteins, including Rothia spp. and immune proteins or glycoproteins, suggested potential host-microbe interactions during lactation. Together, these findings provide a multi-omic perspective on how mammary microbiome dynamics and host responses during lactation may influence neonatal microbial colonization and health.},
}

Animals
*Colostrum/microbiology
*Milk/microbiology
Female
*Proteome/genetics
Multiomics
*Microbiota/genetics
Swine
*Bacteria/classification/isolation & purification/genetics
Metagenomics/methods
Proteomics

@article {pmid42308338,
year = {2026},
author = {Ong, CJN and Nazari, R and Cabuhat, KSP and Ogaya, JB and Ahmed, MM and Shomuyiwa, DO and Musa, SS and Daberechi, OJ and Abdi, YH and Dulay, RMR and Lucero-Prisno, DE},
title = {The mobile resistome in the water-soil-air nexus: horizontal gene transfer and environmental dissemination of antimicrobial resistance genes.},
journal = {FEMS microbiology ecology},
volume = {},
number = {},
pages = {},
doi = {10.1093/femsec/fiag064},
pmid = {42308338},
issn = {1574-6941},
abstract = {The rapid emergence and global dissemination of antimicrobial resistance pose a serious threat to public health, environmental sustainability, and economic development. Central to this crisis is the resistome, defined as the collection of all antimicrobial resistance genes present in pathogenic and non-pathogenic microorganisms across clinical, agricultural, and natural ecosystems. The environmental resistome plays a crucial role in the evolution and transmission of resistance, serving as both a reservoir and a conduit for ARG exchange through horizontal gene transfer. This review provides a comprehensive overview of the structure, diversity, and dynamics of the resistome, with emphasis on the interconnected water-soil-air continuum. Key mechanisms driving resistome dissemination, including mobile genetic elements such as plasmids, integrons, transposons, and bacteriophages, are discussed alongside the major routes of gene transfer, conjugation, transformation, and transduction. The review highlights anthropogenic drivers that intensify resistome expansion, including antibiotic misuse, wastewater discharge, agricultural runoff, and exposure to heavy metals, pesticides, and disinfectants, which promote co-selection. Advances in resistome profiling approaches, such as quantitative PCR, metagenomics, long-read sequencing, and functional metagenomics, are critically evaluated for their capacity to resolve ARG diversity, mobility, and host associations.},
}

@article {pmid42309504,
year = {2026},
author = {Barros, DC and de Freitas, LHK and Gomes, MP},
title = {Microbiome-Informed Pathways Linking Nature-Based Treatment Systems to Antimicrobial Resistance Outcomes.},
journal = {Environmental microbiology},
volume = {28},
number = {6},
pages = {e70358},
doi = {10.1111/1462-2920.70358},
pmid = {42309504},
issn = {1462-2920},
support = {001//Coordenação de Aperfeiçoamento de Pessoal de Nível Superior/ ; 302226/2022-2//Conselho Nacional de Desenvolvimento Científico e Tecnológico/ ; BRD2024011000004//Fundação Araucária/ ; },
mesh = {*Microbiota ; *Drug Resistance, Bacterial ; *Anti-Bacterial Agents/pharmacology ; Wetlands ; *Bacteria/drug effects/genetics ; Rhizosphere ; *Drug Resistance, Microbial ; },
abstract = {Antimicrobial resistance (AMR) is a One Health challenge driven by clinical antibiotic use and environmental processes that shape microbial selection and genetic exchanges. Nature-based solutions (NbS), particularly constructed wetlands, are increasingly used to remove complex contaminant mixtures from aquatic systems. Although these systems often achieve considerable efficiencies, their effects on AMR dynamics remain unclear. This review synthesizes evidence on how aquatic rhizospheres function as microbiome-associated ecological reactors, in which contaminant mixtures, redox gradients and microbial interactions jointly influence resistance. We show that wetlands can function along a continuum between antimicrobial resistance attenuation, persistence, and dissemination, depending on the design, operation, and ecological context. Importantly, the removal of bioactive compounds does not necessarily translate to a reduced resistance risk, as selective pressures may persist within biofilms, sediments, and plant-associated compartments. We propose a microbiome-informed conceptual framework for interpreting AMR in nature-based systems. This perspective identifies potentially modifiable leverage points for understanding, interpreting, and potentially mitigating resistance-related risks and underscores the need for monitoring and risk assessment strategies that extend beyond conventional chemical metrics and incorporate the One Health exposure pathways. Together, these insights reposition wetlands as conditional solutions, whose sustainability depends on explicitly addressing antimicrobial resistance, alongside contaminant removal.},
}

*Microbiota
*Drug Resistance, Bacterial
*Anti-Bacterial Agents/pharmacology
Wetlands
*Bacteria/drug effects/genetics
Rhizosphere
*Drug Resistance, Microbial

@article {pmid42310306,
year = {2026},
author = {Ishimoto, N and He, S and Bogdanov, M and Smith, TK and Frankel, G and Beis, K},
title = {Phospholipid-independent biogenesis and function of the RP4 conjugation pilus.},
journal = {Nature communications},
volume = {},
number = {},
pages = {},
doi = {10.1038/s41467-026-74409-x},
pmid = {42310306},
issn = {2041-1723},
abstract = {Bacterial conjugation, the process of horizontal gene transfer between bacteria, is initiated by mating pair formation (MPF) via a conjugative pilus. Conjugation of the IncP RP4 plasmid is mediated by short mating pili. Here, we report the cryo-EM structure of the RP4 pilus at 2.74 Å resolution. Uniquely, both the structural and quantitative mass spectral analyses revealed that the cyclic TrbC pilin subunit is not lipidated. Consistently, an E. coli pgsA mutant lacking phosphatidylglycerol (PG) can serve as a donor of RP4 but not of F- (pKpQIL), H- (R27) or W- (R388) pili, whose biogenesis and DNA transfer is PG-dependent. RP4 is the first example of a lipid-independent functional mating pilus. This discovery suggests that an amphipathic lipid moiety is not universally essential for the biogenesis of conjugative pili and MPF, providing an alternative model for their assembly and function. These data expand our understanding of the diverse bacterial mechanisms employ to transfer genetic material.},
}

@article {pmid42310404,
year = {2026},
author = {Typas, D},
title = {A horizontal gene-transfer-like mechanism in mammalian cells.},
journal = {Nature structural & molecular biology},
volume = {33},
number = {6},
pages = {896},
doi = {10.1038/s41594-026-01826-3},
pmid = {42310404},
issn = {1545-9985},
}

@article {pmid42311380,
year = {2026},
author = {Liang, L and Shang, Z and Liu, A and Lin, D and Wu, N and Jing, J and Yang, Z and Liu, W},
title = {Genomic characterization of a pathogenic Bacillus licheniformis strain LSDY01: deciphering its genetic diversity and virulence-associated traits.},
journal = {Frontiers in microbiology},
volume = {17},
number = {},
pages = {1815181},
pmid = {42311380},
issn = {1664-302X},
abstract = {BACKGROUND: Bacillus licheniformis is an opportunistic pathogen in clinical settings. However, the emergence of clinical strains carrying horizontally acquired virulence determinants, including chromosomal genomic islands harboring yopX, a putative type IV secretion system (T4SS), and plasmids bearing toxin-antitoxin systems and additional virulence factors, poses a significant challenge to diagnosis and treatment. Moreover, the genetic basis of the pathogenicity of clinical isolates has not been comprehensively studied.

METHODS: A pathogenic B. licheniformis strain (LSDY01) isolated from a skin infection was subjected to whole-genome sequencing and comparative genomic analyses. Phylogenetic reconstruction, pan-genome analysis, and detailed characterization of plasmid and chromosomal virulence determinants were performed. Antimicrobial susceptibility testing was performed according to standardized guidelines. Biofilm formation assays were also conducted. The cytotoxic effect of LSDY01 on HEK293 cells was evaluated using a CCK-8 assay.

RESULTS: Strain LSDY01 belonged to B. licheniformis ST20, differing by only one allele from the prevalent ST3. Its closest relatives were the Daqu-derived strains CP143961.1 and CP143962.1. A unique horizontally acquired genomic island (~157 27 kb, GC 33.03%) and a putative type IV secretion system (T4SS) gene cluster were identified on the chromosome of this strain. A novel plasmid (pLSDY01), which is highly similar to environmental plasmids, harbors yopX, a toxin-antitoxin system, pilT, and a pistol ribozyme. LSDY01 was susceptible to imipenem and vancomycin but resistant to penicillin, erythromycin, and chloramphenicol. The CCK-8 assay revealed a non-significant trend toward reduced HEK293 cell viability after co-culture with LSDY01 (p = 0.0545 at 2 h of CCK-8 incubation).

CONCLUSION: Our findings suggest that horizontal gene transfer, including plasmid acquisition and potential phage integration, may have enabled B. licheniformis to evolve into a pathogen, highlighting the need to reassess the safety of traditionally non-pathogenic microbes.},
}

@article {pmid42313054,
year = {2026},
author = {Hikida, H and Zhang, R and Chen, J and Okazaki, Y and Ogata, H},
title = {Horizontal transfer of a 180-kbp genomic fraction among the largest viral genomes.},
journal = {Applied and environmental microbiology},
volume = {},
number = {},
pages = {e0010526},
doi = {10.1128/aem.00105-26},
pmid = {42313054},
issn = {1098-5336},
abstract = {Viruses are generally considered tiny biological entities with small genomes; however, some dsDNA viruses, known as giant viruses, have large genomes that are comparable to those of small bacteria. These viruses may have evolved from a small ancestor. During their evolution, virus-to-virus horizontal gene transfer has substantially contributed to the expansion of the genomic repertoire of giant viruses. In this study, we identified a horizontal transfer of a large fraction of the genome between viruses in pandoraviruses, a group of giant viruses with the largest genome sizes reaching 2.5 Mbp. We isolated a pandoravirus that belongs to a known viral species. However, its genome size was 200 kbp larger than that of other strains in the same species. Comparative genomics identified a 180-kbp genomic fraction with 168 genes in the newly isolated virus, which may have been horizontally transferred from a distantly related pandoravirus. The gene composition in the 180-kbp region further indicates that this region was already large at the time of the horizontal transfer. Our findings suggest that pandoraviruses can horizontally exchange a large portion of their genomes. This event presumably represents one mechanism for accelerating genomic evolution and gigantism in giant viruses.IMPORTANCEGiant viruses are double-stranded DNA viruses belonging to the phylum Nucleocytoviricota, characterized by large particles and genomes. Previous studies have suggested that these viruses may have evolved from a small ancestor, but the underlying mechanisms are not fully understood. In this study, we isolated one of the largest giant viruses, pandoravirus, which belongs to a known viral species but has a genome 200 kbp larger than that of other strains in the same species. Comparative genomics identified a 180-kbp genomic fragment containing 168 genes in the newly isolated virus that is absent from other strains of the same species. Further comparative analysis indicated that this 180-kbp region has been horizontally transferred from a distantly related pandoravirus. Our findings suggest that giant viruses can exchange a massive number of genes by a horizontal transfer of a large genomic fraction, which may have contributed to their gigantism.},
}

@article {pmid42313083,
year = {2026},
author = {Holtappels, D and Rickus, GEJ and Morgan, T and de Rezende, RR and Koskella, B and Alfenas-Zerbini, P},
title = {Erratum: Comparative genomics reveals high prophage diversity and horizontal gene transfer of effectors and phage defence systems in the Pseudomonas syringae complex.},
journal = {Microbial genomics},
volume = {12},
number = {6},
pages = {},
doi = {10.1099/mgen.0.001761},
pmid = {42313083},
issn = {2057-5858},
}

@article {pmid42313157,
year = {2026},
author = {Cardenas Alegria, OV and Torres, MC and Breyer, GM and Rebelatto, R and Wuaden, CR and Pastore, J and Lazzarotti, M and Ramos, RTJ and Dorn, M and Kich, JD and Siqueira, FM},
title = {Dynamics of Bacterial Communities and Resistomes Across Swine Waste Stabilization Ponds and Fertilized Soils.},
journal = {Current microbiology},
volume = {83},
number = {8},
pages = {},
pmid = {42313157},
issn = {1432-0991},
mesh = {Animals ; Swine ; *Bacteria/genetics/classification/drug effects/isolation & purification ; *Soil Microbiology ; *Manure/microbiology ; *Drug Resistance, Bacterial/genetics ; *Ponds/microbiology ; Interspersed Repetitive Sequences ; Anti-Bacterial Agents/pharmacology ; Fertilizers/analysis ; Soil/chemistry ; Metagenomics ; Genes, Bacterial ; *Microbiota ; },
abstract = {The environmental dissemination of antimicrobial resistance (AMR) through livestock waste represents a growing concern for human, environmental, and animal health. This study investigated how swine waste stabilization ponds (WSPs), and subsequent manure application to agricultural soils, influence bacterial community structure, antimicrobial resistance genes (ARGs), and mobile genetic elements (MGEs). Using shotgun metagenomics, we analyzed 80 samples from 20 swine farms, including waste collected before and after WSP treatment and soils with and without a history of manure application. Distinct microbial profiles were observed between waste and soil environments. Waste samples were dominated by Bacillota, Bacteroidota, and Pseudomonadota, whereas soils were enriched in Actinomycetota, particularly Streptomyces. WSP significantly reduced microbial diversity and caused shifts toward stress-tolerant taxa, indicating selective pressures during the process. Manure-fertilized soils exhibited altered community composition and enrichment of clinically relevant ARGs, including the fluoroquinolone resistance gene adeF. Waste management practices influenced resistome composition, with treated waste showing increased relative abundance of macrolide resistance genes (ermB and mefA). In soils, ARG profiles were associated with distinct MGE patterns, suggesting environment-specific mechanisms of gene mobility. Phage-associated elements were more prevalent in waste samples, whereas transposons were more prominent in soils, where ARG-MGE co-occurrence patterns indicated potential for horizontal gene transfer. Overall, our findings demonstrate that WSP management and soil application of swine manure shape both microbial communities and resistome configurations. These results underscore the importance of integrating waste treatment strategies into AMR surveillance frameworks and support a One Health approach to mitigate its dissemination in agroecosystems.},
}

Animals
Swine
*Bacteria/genetics/classification/drug effects/isolation & purification
*Soil Microbiology
*Manure/microbiology
*Drug Resistance, Bacterial/genetics
*Ponds/microbiology
Interspersed Repetitive Sequences
Anti-Bacterial Agents/pharmacology
Fertilizers/analysis
Soil/chemistry
Metagenomics
Genes, Bacterial
*Microbiota

@article {pmid42313295,
year = {2026},
author = {Asgharzadeh, S and Pourhajibagher, M and Bahador, A},
title = {Bacterial extracellular vesicles: emerging players in antimicrobial resistance and clinical translation.},
journal = {Molecular biology reports},
volume = {53},
number = {1},
pages = {},
pmid = {42313295},
issn = {1573-4978},
mesh = {*Extracellular Vesicles/metabolism/genetics ; Humans ; *Bacteria/metabolism/drug effects/genetics/pathogenicity ; *Drug Resistance, Bacterial/genetics ; Anti-Bacterial Agents/pharmacology ; Gene Transfer, Horizontal ; Animals ; Bacterial Infections/drug therapy/microbiology ; Drug Resistance, Multiple, Bacterial ; },
abstract = {Antimicrobial resistance (AMR) represents a critical and escalating global health challenge that extends beyond classical genetic mechanisms of resistance acquisition. Increasing evidence highlights extracellular vesicles (EVs) as key mediators of bacterial adaptation, intercellular communication, and resistance dissemination. Among these, bacterial extracellular vesicles (BEVs) play a central role by transporting diverse cargo, including antibiotic resistance genes, mobile genetic elements, antibiotic inactivating enzymes, and immunomodulatory factors. By facilitating horizontal gene transfer (HGT) and non-genetic resistance mechanisms such as antibiotic sequestration, extracellular neutralization, and biofilm reinforcement, BEVs contribute to the emergence and persistence of multidrug-resistant (MDR) infections. This review critically examines the biogenesis, cargo composition, and functional roles of BEVs in bacterial pathogenesis and AMR, while also discussing the complementary influence of host-derived EVs on infection dynamics and antimicrobial responses. We assess emerging evidence supporting EVs as non-invasive biomarkers for resistance surveillance and as adaptable platforms for vaccine development and targeted antimicrobial delivery. Finally, we highlight key unresolved challenges, including vesicle heterogeneity, limited understanding of cargo selection mechanisms, and the lack of standardized isolation and characterization protocols, which must be addressed to enable the clinical and translational integration of EV-based strategies in combating AMR.},
}

*Extracellular Vesicles/metabolism/genetics
Humans
*Bacteria/metabolism/drug effects/genetics/pathogenicity
*Drug Resistance, Bacterial/genetics
Anti-Bacterial Agents/pharmacology
Gene Transfer, Horizontal
Animals
Bacterial Infections/drug therapy/microbiology
Drug Resistance, Multiple, Bacterial

@article {pmid42299635,
year = {2026},
author = {Cunha da Silva, G and Rossi, CC},
title = {Global One Health genomics identify conserved virulence and mobile resistance in the opportunistic pathogen Staphylococcus saprophyticus.},
journal = {Future microbiology},
volume = {},
number = {},
pages = {1-10},
doi = {10.1080/17460913.2026.2688716},
pmid = {42299635},
issn = {1746-0921},
abstract = {AIMS: To define the global genomic landscape of Staphylococcus saprophyticus and evaluate the contribution of human, animal, food, and environmental strains to the dissemination of antimicrobial resistance and virulence traits within a One Health framework.

MATERIALS AND METHODS: A total of 975 publicly available genomes were analyzed using comparative genomics to characterize the resistome, virulome, and mobilome. Associations between antimicrobial resistance genes and mobile genetic elements were assessed. Ribosomal multilocus sequence typing (rMLST) was used to investigate population structure and lineage distribution across sources and geographic regions.

RESULTS: S. saprophyticus showed a global distribution across diverse hosts. A subset of rMLSTs (48500, 48501, 48492, and 48498) accounted for ~52% genomes and were widely distributed across countries and sources. Multidrug resistance was detected in all regions and frequently associated with plasmids, prophages, and integrative and conjugative elements, which together carried nearly half of resistance genes. In contrast, virulence determinants were largely chromosomal and conserved, supporting a stable pathogenic repertoire across ecological contexts.

CONCLUSIONS: These findings highlight the circulation of dominant lineages across multiple reservoirs and identify non-clinical environments as important contributors to the spread of clinically relevant resistance and virulence traits.},
}

@article {pmid42300741,
year = {2026},
author = {Mei, Z and Rodríguez, EA and Balcázar, JL},
title = {Plastic pollution and antimicrobial resistance: an emerging link with major implications.},
journal = {Applied and environmental microbiology},
volume = {},
number = {},
pages = {e0097326},
doi = {10.1128/aem.00973-26},
pmid = {42300741},
issn = {1098-5336},
abstract = {Plastic pollution and antimicrobial resistance are increasingly interconnected global threats. Micro- and nanoplastics create ecological hotspots that enhance microbial interactions and horizontal gene transfer, facilitating antimicrobial resistance dissemination. Here, we argue that the plastisphere acts as an evolutionary interface that reshapes microbial adaptation and resistome dynamics across ecosystems. Current antimicrobial resistance surveillance frameworks largely overlook the contribution of plastic pollution, highlighting the need to integrate plastisphere-mediated processes into One Health and environmental risk assessment strategies.},
}

@article {pmid42302690,
year = {2026},
author = {Li, X and Wen, S and Yu, C and Zhang, J and Xu, W and Yue, Z and Zhang, J},
title = {Dynamic evolution of the antibiotic resistome and mobilome on the microplastics of hospital wastewater.},
journal = {Journal of environmental management},
volume = {412},
number = {},
pages = {130243},
doi = {10.1016/j.jenvman.2026.130243},
pmid = {42302690},
issn = {1095-8630},
abstract = {Antimicrobial resistance is a major global health threat. Hospital wastewater serves as a significant reservoir for both microplastics (MPs) and antibiotic resistance genes (ARGs). MPs have recently been recognized not only as persistent pollutants but also as novel ecological niches for microbial colonization. However, the underlying mechanisms and key biological carriers driving MPs - mediated antimicrobial resistance transmission in hospital wastewater remain unclear. Here, we quantified the occurrence and characteristics of MPs in hospital wastewater and combined an incubation experiment with metagenomic sequencing to resolve the temporal dynamics of ARGs, mobile genetic elements (MGEs), and virulence factors (VFs) on MPs surfaces. MPs reached an abundance of 9.5 particles/L, with polyethylene (PE) dominating. Across the 28-day colonization period, with samples collected at 7, 14, 21, and 28 days, 68 ARGs, 443 MGEs and 414 VFs were detected, along with 129 prophage, highlighting the potential for enhanced horizontal gene transfer (HGT) in the plastisphere. We further reconstructed 360 metagenome-assembled genome (MAGs) spanning 16 phyla, and identified Pseudomonadota and Bacteroidota as core hosts of ARGs on MPs. Variance partitioning analysis revealed that MGEs were the major drivers of ARGs variation, independently explaining 44.4% of the dynamics. Our findings provide new insights into the ecological processes of antibiotic resistome of the MPs in the hospital wastewater.},
}

@article {pmid42303717,
year = {2026},
author = {Kamil, V and Yazdanmanesh, M and Tadayon, K and Khoshnood, S and Kalani, BS and Kazemian, H},
title = {Molecular characterization and antimicrobial resistance profiles of Shigella flexneri isolates from pediatric clinical cases in Ahvaz, Iran.},
journal = {Scientific reports},
volume = {},
number = {},
pages = {},
doi = {10.1038/s41598-026-57416-2},
pmid = {42303717},
issn = {2045-2322},
abstract = {Shigella is a highly invasive pathogen that causes dysentery and is associated with significant morbidity and mortality in children under five years of age. This agent is a major public health problem in developing countries. Multiple-locus variable-number tandem repeat (VNTR) analysis (MLVA) is a reliable, cost-effective typing method with high discriminatory power and reproducible results. The rise of drug resistance in Shigella strains is a growing global health threat. Despite the significance of Shigella in Iran, there is limited knowledge about genetic diversity and drug resistance profiles of local strains. Therefore, the purpose of this study was to characterize the genetic diversity and drug resistance profiles of Shigella strains isolated in Ahvaz, Iran. A total of 49 Shigella flexneri isolates were recovered from 500 stool samples of pediatric patients. Routine biochemical tests were used to identify all isolates. Antimicrobial susceptibility testing was performed, and resistance genes were detected by polymerase chain reaction (PCR). Extended-spectrum β-lactamases (ESBL), carbapenemase, and Metallo-β-lactamase (MBL) production were detected phenotypically using combination disk assays and confirmed by the CLSI-recommended modified Carbapenem inactivation method (mCIM) and EDTA-modified carbapenem inactivation method (eCIM). MLVA based on seven VNTR loci was performed to characterize the genetic diversity of the isolates. All 49 isolates were resistant to ceftazidime, trimethoprim/sulfamethoxazole, ampicillin, and ceftriaxone (100% each). High resistance rates were also observed for imipenem 36/49 (73.5%), meropenem 36/49 (73.5%), azithromycin 21/49 (42.9%), and ciprofloxacin 16/49 (32.7%). Furthermore, phenotypic testing revealed ESBL production in 46/49 (93.9%) isolates and carbapenemase activity in 36/49 (73.5%), of which 22/49 (44.9%) were MBL. PCR analysis identified blaCTX-M 38/49 (77.6%) and blaSHV 35/49 (71.4%) as the most prevalent ESBL genes, whereas blaNDM 14/49 (28.6%), and blaOXA-48 14/49 (28.6%) were the most common carbapenemase genes. MLVA typing divided the isolates into 22 different MLVA types, including 10 clusters and 12 singletons, and locus ms21 showed the highest discriminatory power. The isolates exhibited high genetic diversity with a non-clonal distribution of resistance, which indicates dissemination through horizontal gene transfer. Our results demonstrated that mCIM/eCIM and MLVA are viable methods for investigating Shigella species as they are cost-effective, provide quick results, and allow for easy sharing of numerical data between laboratories.},
}

@article {pmid42304007,
year = {2026},
author = {Alam, SA and Karmakar, D and Khan, B and Mandal, R and Bhattacharya, S and Ahmed, I and Maruyama, F and Saha, P},
title = {Polyphasic taxonomic characterization of Brachybacterium netajii sp. nov., a metabolically versatile bacterium isolated from the river Ganges, India.},
journal = {Scientific reports},
volume = {},
number = {},
pages = {},
doi = {10.1038/s41598-026-56775-0},
pmid = {42304007},
issn = {2045-2322},
abstract = {A comprehensive polyphasic taxonomic strategy was applied to the systematic characterization of strain DNPG3[T], which was isolated from the river Ganges, Hooghly, West Bengal, India. The Gram-positive, halotolerant, heavy-metal-tolerant strain exhibited the ability to degrade p-nitrophenol (PNP). Cellular fatty acid analysis revealed that the predominant components were anteiso-C15:0 (24.61%), C11:0 (21.06%), iso-C16:0 (11.89%), C16:0 (11.58%), and anteiso-C17:0 (11.24%). Notably, the presence of C11:0, C10:0 2-OH as major fatty acids differentiate strain DNPG3[T] from its closely related members of the genus Brachybacterium. The predominant respiratory quinone was identified as menaquinone-7 (MK-7). Analysis of 16S rRNA gene sequence indicated that B. zhongshanense strain JB[T] was the closest relative of DNPG3[T], sharing 97.08% sequence similarity. Genome-based ANI value calculated using the EzBioCloud server revealed that B. zhongshanense JCM 15471[T] was the closest genomic relative (85.49%). These values were further substantiated by digital DNA-DNA hybridization (dDDH) estimates calculated using the GGDC server. Taxonomic assignment using the GTDB database further indicated that strain DNPG3[T] constitutes a previously unrecognized species within the genus Brachybacterium. Genome analysis of strain DNPG3[T] identified eleven genomic islands, along with a rich repertoire of 194 carbohydrate-active enzyme (CAZyme) families, comprising 95 glycoside hydrolases and 53 glycosyltransferases. In addition, five biosynthetic gene clusters were detected. Collectively, these genomic features indicate the involvement of horizontal gene transfer events and highlighted the pronounced metabolic versatility of the strain, underscoring its potential for industrial enzyme production and secondary metabolite biosynthesis. Pan-genome analysis further indicates that the Brachybacterium pan-genome is open, reflecting substantial genetic diversity and ongoing gene acquisition within the genus. Comprehensive biochemical, physiological, chemotaxonomic, and phylogenetic analyses supported the assignment of strain DNPG3[T] to the genus Brachybacterium while clearly distinguishing it from all currently described species within the genus. Accordingly, strain DNPG3[T] was proposed to represent a novel species, for which the name Brachybacterium netajii sp. nov. is suggested. The type strain was DNPG3[T] (= MTCC13125[T]).},
}

@article {pmid42304249,
year = {2026},
author = {Whitehead-Tillery, CE and Waite, SE and Durand-Piña, GAE and Green, EK and Bell, JA and Zhang, L and Mansfield, LS},
title = {Genomic analysis reveals close genetic similarity between ESBL and other β-lactamase-producing E. coli isolates from humans and dogs, suggesting potential for inter-species transmission.},
journal = {BMC genomics},
volume = {},
number = {},
pages = {},
doi = {10.1186/s12864-026-13015-z},
pmid = {42304249},
issn = {1471-2164},
abstract = {BACKGROUND: Extended-spectrum β-lactamase-(ESBL)-producing Enterobacteriaceae are emerging in hospital and community settings as important causes of urinary tract infections. These plasmid-mediated enzymes have been identified in human and dog hosts, with blaCTX-M variants being the most prevalent ESBLs worldwide. Our objective was to identify horizontal gene transfer (HGT) events amongst human and dog-derived ESBL-producing bacteria by examining genetic relatedness of plasmid and bacterial whole genome sequences (WGS) associated with ESBLs and other β-lactamase genes. By understanding genetic relatedness, we aimed to provide insight into transmission dynamics of ESBLs and antibiotic resistance among humans and dogs in community-acquired settings.

RESULTS: Of 149 plasmids collected from humans (n = 125) and dogs (n = 24), 111 (74.5%) carried class A ESBL genes with blaCTX-M-14 (31.6%) predominating in human-derived plasmids and blaCTX-M-1 in dog-derived plasmids (29.6%). In addition, ESBLs and other β-lactamase genes, including blaTEM-1,were also identified in both populations. pMLST showed that IncF, IncI1, and IncN plasmids were the main groups contributing to the dissemination of ESBLs amongst human and dog populations. Neighbor-joining analysis revealed clustering of human and dog-derived plasmids carrying similar ESBL genes as well as other antibiotic-resistant genes. The maximum-likelihood tree revealed a high predominance of ST131 carried by E. coli serotypes O25:H4 in humans but not dogs. Virulence gene analysis revealed that ESBL-producing bacteria were not limited to UPEC.

CONCLUSIONS: The presence of conserved ESBLs, other β-lactamase genes and E. coli clones in both humans and dogs highlights widespread circulation of shared resistance elements. These findings support the need for broader One Health surveillance, particularly involving companion animals, to better track and mitigate ARG spread in community settings.},
}

@article {pmid42306866,
year = {2026},
author = {Roulet, ME and Ceriotti, LF and Gatica Soria, LM and Tulle, WD and Sanchez-Puerta, MV},
title = {A structural solution to functional HGT: gene chimaerism bypasses mitochondrial expression barriers in parasitic plants.},
journal = {Proceedings. Biological sciences},
volume = {293},
number = {2073},
pages = {},
doi = {10.1098/rspb.2025.2955},
pmid = {42306866},
issn = {1471-2954},
support = {//Fondo para la Investigación Científica y Tecnológica/ ; //Secretaría de Investigación, Internacionales y Posgrado, Universidad Nacional de Cuyo/ ; },
mesh = {*Gene Transfer, Horizontal ; *Genome, Mitochondrial ; *Genes, Mitochondrial ; Mitochondria/genetics ; },
abstract = {Horizontal gene transfer (HGT) in plant mitochondria is frequent, yet acquired genes are rarely functional due to expression barriers. The holoparasitic plant Lophophytum mirabile (Balanophoraceae) is an exceptional case, having functionally replaced numerous native mitochondrial genes with host-derived xenologues. This system provides a unique opportunity to investigate the mechanisms of functional HGT assimilation. Here, we assembled mitochondrial genomes of the sister species L. pyramidale and their mimosoid hosts and analysed expression data from both holoparasites. We show that this extensive functional integration occurred without the co-transfer of nuclear regulatory factors; Lophophytum relies entirely on its pre-existing native machinery. Our results demonstrate that the primary mechanism enabling Lophophytum to overcome the transcription barrier is structural: most functional xenologues are chimaeric and retain native 5' regions that probably place foreign coding sequences under the control of a recognizable native promoter. This structural solution is complemented by post-transcriptional flexibility, as the RNA editing machinery efficiently processes novel host-specific sites. However, functional replacement appears biased towards genes with inherently low editing requirements and no introns, highlighting a strong selective filter. Taken together, our results show that functional integration is driven by a combination of structural integration and the flexibility of the native regulatory system.},
}

*Gene Transfer, Horizontal
*Genome, Mitochondrial
*Genes, Mitochondrial
Mitochondria/genetics

@article {pmid42307236,
year = {2026},
author = {Liu, Y and Liu, Y},
title = {Gain and loss of plasmid-borne antibiotic resistance genes are associated with chromosomal resistance presence in Enterobacteriaceae.},
journal = {mSystems},
volume = {},
number = {},
pages = {e0041226},
doi = {10.1128/msystems.00412-26},
pmid = {42307236},
issn = {2379-5077},
abstract = {Plasmids are central vehicles for the dissemination of antibiotic resistance genes (ARGs). They are among the most mobile and evolvable genetic elements, with broad host ranges and high rates of gene turnover, making them especially effective in spreading antibiotic resistance across bacterial lineages. Using the phylogeny-aware gene gain and loss model applied to 6,895 Enterobacteriaceae genomes, we quantified four evolutionary processes-gene gain, loss, expansion, and reduction-for plasmid-borne genes. We found that, overall, plasmid-borne ARGs (pARGs) exhibit similar gain rates compared with other plasmid genes, but significantly higher expansion and reduction rates. All four processes were strongly species-dependent, with only a minor influence of antibiotic class. Furthermore, bacterial clades harboring chromosomal ARGs (cARGs) showed significantly higher acquisition and lower loss of plasmid-borne resistance than did their sister clades lacking corresponding cARGs. Moreover, we found that the IncQ2 backbone was associated with qnrS2 and exclusively identified in Leclercia adecarboxylata, while Col(VCM04) plasmids carrying mprF were predominantly (71.4%) distributed within the Citrobacter genus. In summary, plasmid-mediated resistance is primarily species-dependent, and cARGs effectively mark lineages with a high capacity for plasmid-borne resistance acquisition.IMPORTANCEPlasmids play a central role in the spread of antibiotic resistance genes (ARGs), and the long-term evolutionary behavior of plasmid-borne ARGs (pARGs) could provide insights into the emergence of novel multidrug resistance. We studied nearly 7,000 Enterobacteriaceae genomes and show that pARGs evolve through the same gain processes as other plasmid genes but exhibit markedly higher and species-dependent copy number changes. Crucially, the strong association between chromosomal and plasmid ARGs reflect a lineage-level pattern of resistance retention, likely shaped by historical selective pressures or specific genomic backgrounds. Identifying such evolutionary lineages may provide a basis for predicting and monitoring the emergence of multidrug resistance.},
}

@article {pmid42296092,
year = {2026},
author = {Westley, J and Bedekar, P and Pursey, E and Szczelkun, MD and Recker, M and van Houte, S and Westra, ER},
title = {Eco-evolutionary feedbacks drive the co-occurrence of restriction-modification systems and antimicrobial resistance genes in bacteria.},
journal = {PLoS biology},
volume = {24},
number = {6},
pages = {e3003842},
doi = {10.1371/journal.pbio.3003842},
pmid = {42296092},
issn = {1545-7885},
abstract = {Bacterial pathogens commonly become drug resistant via horizontal acquisition of antimicrobial resistance genes (ARGs), which are often encoded on mobile genetic elements (MGEs). Although bacterial defence systems are typically considered barriers to horizontal gene transfer (HGT), previous studies revealed that bacteria with more restriction-modification (RM) systems (the most abundant bacterial defences) frequently carry more MGEs. It was suggested that this counterintuitive relationship might result from stronger selection for RM systems when exposure to costly MGEs increases. Here, we test this hypothesis using a combination of modeling and bioinformatics analysis of >40,000 bacterial genomes to better understand how eco-evolutionary feedbacks between selection for RM and acquisition of MGEs shape bacterial genome evolution. Our model predicts negative associations between HGT and RM, but only if RM diversity is high. By contrast, at low RM diversity, eco-evolutionary feedbacks drive the emergence of positive associations between HGT and RM. Consistent with these predictions, we identified negative relationships between acquired ARG counts and RM counts across species but positive relationships within individual species. Collectively, our work helps to understand how RM systems shape patterns of HGT of ARGs, which may offer opportunities for targeted surveillance of strains at higher risk of horizontally acquiring novel drug resistance alleles.},
}

@article {pmid42296180,
year = {2026},
author = {Hamelin, RC and Stewart, JE and Hadziabdic, D},
title = {Tree Killer, Qu'est-ce Que C'est? Insights From Forest Pathogen Genomes.},
journal = {Annual review of phytopathology},
volume = {},
number = {},
pages = {},
doi = {10.1146/annurev-phyto-021621-114843},
pmid = {42296180},
issn = {1545-2107},
abstract = {Forests are central to planetary health but are increasingly challenged by emerging diseases driven by climate change, global trade, and anthropogenic disturbance. Despite the apparent resilience of long-lived, genetically diverse tree hosts, forest ecosystems have repeatedly experienced landscape-level pathogen-driven transformations. Advances in genomics, transcriptomics, and functional biology have transformed our understanding of how fungal and oomycete pathogens interact with their hosts across a continuum of lifestyles, from saprotrophy and necrotrophy to biotrophy. Here, we synthesize insights from comparative and population genomics and functional studies across diverse forest pathosystems to examine the traits that characterize successful tree pathogens. We highlight how lifestyle plasticity, adaptations to woody tissues, vector-mediated transmission, and biotrophic stealth enable pathogens to colonize perennial hosts and persist over long temporal scales. We further examine how genome plasticity, hybridization, and horizontal gene transfer generate adaptive potential that often outpaces host evolutionary responses under current environmental change. Finally, we discuss emerging genomic tools, including biosurveillance, machine learning-based classification, and genome editing, that are beginning to link genotype to phenotype and inform assessments of disease risk. By integrating genomic, ecological, and evolutionary perspectives, this review outlines general principles governing forest pathogen success and identifies priorities for future research aimed at improving understanding, early detection, and management of forest diseases in a changing world.},
}

@article {pmid42296358,
year = {2026},
author = {Ewart, KM and Adams, MWD and Zhang, Z and Baker, L and Fujiwara, K and Hayashi, Y and Featherstone, LA and Lu, OL and Helbling, JES and Moral, M and Maekawa, K and Rose, H and Jex, A and Ho, SYW and Lo, N},
title = {Uncovering thousands of endosymbiont DNA transfer events within single cockroach genomes.},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {123},
number = {25},
pages = {e2604240123},
doi = {10.1073/pnas.2604240123},
pmid = {42296358},
issn = {1091-6490},
support = {FT160100463//Australian Research Council/ ; DP220103265//Australian Research Council/ ; },
mesh = {Animals ; *Gene Transfer, Horizontal ; *Cockroaches/genetics/microbiology ; *Symbiosis/genetics ; Phylogeny ; *Genome, Insect ; Evolution, Molecular ; },
abstract = {Horizontal gene transfer (HGT) between organisms can be a valuable source of genetic variation and innovation. Research on HGT in eukaryotes has hitherto focused on transfers of coding sequences; insertions of noncoding DNA remain poorly understood. Here, we investigated HGT in cockroaches, which have a long-standing evolutionary relationship with the transovarially transmitted endosymbiont Blattabacterium cuenoti, making them a valuable system for assessing the potential scale of HGT. We aligned 150-bp genomic fragments of B. cuenoti to 23 cockroach and termite genomes, including 8 genomes newly sequenced, and revealed pervasive endosymbiont DNA transfer events. Australian panesthiine and geoscapheine cockroaches were consistently found to harbor >3000 HGT inserts, more than an order of magnitude higher than the previous maximum estimate in other eukaryotes, excluding rotifers. Some inserts appear to have persisted for ≥28.7 million years in this group, which may reflect functional roles. We identified numerous chimeric inserts comprising up to nine short segments from different locations in the B. cuenoti genome. Our findings indicate pervasive HGT in eukaryote genomes, with potentially far-reaching implications for adaptation and speciation.},
}

Animals
*Gene Transfer, Horizontal
*Cockroaches/genetics/microbiology
*Symbiosis/genetics
Phylogeny
*Genome, Insect
Evolution, Molecular

@article {pmid42296904,
year = {2026},
author = {Ababii, M and Bohuon, V and Chane, A and Poc, CD},
title = {Atmospheric pollutants and airborne bacteria: adaptation mechanisms, virulence modulation, and public health implications.},
journal = {The Science of the total environment},
volume = {1044},
number = {},
pages = {181950},
doi = {10.1016/j.scitotenv.2026.181950},
pmid = {42296904},
issn = {1879-1026},
abstract = {Outdoor air pollution is a major public health issue. Many studies correlate ambient air pollution with acute and chronic pulmonary disease. However, its interactions with airborne bacteria remain insufficiently characterized. In particular, the mechanisms linking pollutants to microbial adaptation and pathogenicity are not clearly established. An increasing body of evidence shows that airborne bacteria respond actively to atmospheric pollutants. These responses affect their survival, behavior, and functional traits. However, a comprehensive synthesis of pollutant-driven microbial adaptation and its implications for virulence and public health, is still lacking. This review synthesizes current knowledge on the interactions between atmospheric pollutants and airborne bacteria within an integrative mechanistic and One Health framework. The nature and sources of major atmospheric pollutants are first outlined. The mechanisms by which these pollutants induce oxidative and nitrosative stress in bacteria are then analyzed, with a focus on the generation of reactive oxygen and nitrogen species and their cellular impacts. Bacterial adaptive responses to these stresses are subsequently discussed. These include antioxidant defenses, membrane remodeling, biofilm formation, and horizontal gene transfer. The potential contribution of these processes to bacterial persistence, virulence-associated traits, and antibiotic resistance is discussed. The implications for human and environmental health are then addressed. Particular attention is given to respiratory infections, the enrichment of airborne resistomes, and the emergence of opportunistic taxa in polluted environments. Finally, future research directions including key knowledge gaps are summarized.},
}

@article {pmid42297254,
year = {2026},
author = {Ma, R and Li, X and Tang, R and Liu, Y and Wang, J and Li, G and Li, S and Tian, S and Jiang, T and Chang, J and Yuan, J},
title = {Two-phase removal kinetics of antimicrobial resistance in collaborative composting: Thermophilic enhancement and rebound suppression.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {135174},
doi = {10.1016/j.biortech.2026.135174},
pmid = {42297254},
issn = {1873-2976},
abstract = {Temperature significantly affects antimicrobial resistance (AMR) during composting, but its role in multi-material co-composting remains unclear. This study explored temperature effects on pathogen inactivation, antibiotic resistance gene (ARG) removal, and host dynamics. Three composting regimes were established based on temperature: thermophilic (TC, <65 °C), superthermophilic (SC, 65-75 °C), and hyperthermophilic (HC, >75 °C). Fecal coliforms were inactivated within 2 days at > 65 °C, compared to 3 days at 40-50 °C. Temperatures exceeding 65 °C accelerated pathogen elimination, achieving over 98% reduction by day 28. During the thermophilic phase, elevated temperatures (>65 °C) suppressed vertical gene transfer and removed 95%-97% of ARGs by day 28. In the maturation phase, maintaining moisture content (MC) below 40% mitigated ARG rebound by restricting horizontal gene transfer, bacterial activity, and mobile genetic elements (MGEs). Six high-risk ARGs (tetW, aadE, ermX, ermB, sul1, tetM) and their pathogenic hosts (Enterococcus, Escherichia, Streptococcus, Clostridium, Corynebacterium) were identified. By day 28, treatments exceeding 65 °C eliminated 96%-99% of pathogens, high-risk ARGs, and their hosts, with no ARG rebound detected in the final compost. Overall, maintaining composting temperatures above 65 °C for at least five consecutive days and controlling final MC below 40% constitutes an effective strategy for mitigating AMR risks in multi-material co-composting. This study provides both theoretical and technical foundations for managing antibiotic resistance risks during composting.},
}

@article {pmid42299085,
year = {2026},
author = {Ghafoor, M and Saqib, M and Ashfaq, K and Rehman, SU},
title = {Novel capsular diversity and antimicrobial resistance determinants of Staphylococcus aureus associated with bovine and bubaline mastitis.},
journal = {Polish journal of veterinary sciences},
volume = {29},
number = {2},
pages = {313-326},
doi = {10.24425/pjvs.2026.1277},
pmid = {42299085},
issn = {2300-2557},
mesh = {Animals ; *Staphylococcus aureus/drug effects/genetics ; Cattle ; *Mastitis, Bovine/microbiology/epidemiology ; Female ; *Staphylococcal Infections/veterinary/microbiology/epidemiology ; *Drug Resistance, Bacterial ; *Anti-Bacterial Agents/pharmacology ; *Buffaloes ; *Bacterial Capsules/genetics ; Gene Expression Regulation, Bacterial/physiology ; },
abstract = {In Pakistan, bovine mastitis has been identified as one of the biggest limitations to dairy production, and Staphylococcus aureus has been identified as one of the most enduring and economically relevant mastitogens. The current study was conducted to examine the capsular genotype and antimicrobial resistance (AMR) of S. aureus isolated from cases of clinical and subclinical mastitis in cows and buffaloes of the Punjab and Sindh provinces. One hundred and fifty S. aureus isolates (109 from cows and 41 from buffaloes) were isolated out of 87 dairy herds and verified using nuc gene-based PCR. Genotyping of capsular polysaccharide (CP) demonstrated that there were only cap5 (56%) and cap8 (44%) loci, but no cap1 and cap2. The cap5 was the most common among clinical (20.66%) and subclinical (35.33%) isolates, whereas cap8 had a frequency of 12.66% and 31.33% in clinical and subclinical isolates, respectively, suggesting that CP5 and CP8 are the common circulating types of capsular pathogens in the study areas. The antimicrobial susceptibility testing involving 13 routine antimicrobial agents revealed that 92% of isolates were resistant to one or more antimicrobials, and 63.3% of the isolates were multidrug-resistant (MDR). The greatest resistance was found with penicillin (72.66%), then amoxicillin (53.33%), and amoxicillin-clavulanic acid (37.33%). Those resistant to methicillin (3.33%) were mecA-positive MRSA, but no isolate was positive for mecC. Molecular screening showed that the prevalence of the blaZ gene (95.33%) was high and in line with the prevalence of resistance mediated by β-lactamase. The tetM (92.10%) and tetK (84.21%) were most common among the tetracycline-resistant isolates. The determinants of macrolide resistance were msrC (87.5%), ermB and ermC, and the aac-aphD aminoglycoside resistance gene was also present in 17.64% of resistant isolates. Resistance to critically important antimicrobials like vancomycin and linezolid was low, and optrA was not identified. Strong genotype-phenotype concordance was shown by correlation analysis to occur in 22 cases where 2 beta-lactam, tetracycline, and macrolide resistance determinants were genotyped and phenotyped, indicating the occurrence of co-selection and possible horizontal gene transfer. This study provides the first comprehensive molecular epidemiological insight in bovine and bubaline S. aureus capsular diversity, as well as AMR determinants of S. aureus, in Punjab and Sindh. The prevalence of CP5/CP8 is in favor of their inclusion in vaccine development, whereas high rate of MDR burden evidences the urgency of antimicrobial stewardship and long term molecular surveillance within one health paradigm.},
}

Animals
*Staphylococcus aureus/drug effects/genetics
Cattle
*Mastitis, Bovine/microbiology/epidemiology
Female
*Staphylococcal Infections/veterinary/microbiology/epidemiology
*Drug Resistance, Bacterial
*Anti-Bacterial Agents/pharmacology
*Buffaloes
*Bacterial Capsules/genetics
Gene Expression Regulation, Bacterial/physiology

@article {pmid40643607,
year = {2025},
author = {Soonsanga, S and Rungrod, A and Utamatho, M and Trakulnaleamsai, C and Paenpong, P and Pootakham, W and Phaonakrop, N and Roytrakul, S and Promdonkoy, B},
title = {Integrated genomic and proteomic analysis of local Bacillus thuringiensis isolates for targeted insect pest control and functional insight.},
journal = {Archives of microbiology},
volume = {207},
number = {9},
pages = {193},
pmid = {40643607},
issn = {1432-072X},
support = {P2351509//National Science and Technology Development Agency, Thailand/ ; P2351509//National Science and Technology Development Agency, Thailand/ ; P2351509//National Science and Technology Development Agency, Thailand/ ; P2351509//National Science and Technology Development Agency, Thailand/ ; P2351509//National Science and Technology Development Agency, Thailand/ ; P2351509//National Science and Technology Development Agency, Thailand/ ; P2351509//National Science and Technology Development Agency, Thailand/ ; P2351509//National Science and Technology Development Agency, Thailand/ ; P2351509//National Science and Technology Development Agency, Thailand/ ; },
abstract = {Bacillus thuringiensis (Bt) produces insecticidal crystal proteins and is widely used in pest control. Efficient strain selection for specific targets can be enhanced by integrating genomic and proteomic data. In this study, we sequenced 72 local Bt isolates and selected 12 for detailed proteomic and bioassay analyses. Expressed toxins were identified, and larval assays confirmed high toxicity in selected strains. Bt117 showed 16-fold higher toxicity against Spodoptera frugiperda compared to commercial strain B. thuringiensis serovar kurstaki, while Bt117 and Bt506 were similarly effective against Helicoverpa armigera. Comparative genomics revealed that vip3A expression is regulated by VipR, a finding confirmed experimentally. Phylogenetic analysis indicated that Bt117 and Bt202 are genomically divergent and more closely related to Bacillus cereus, suggesting horizontal gene transfer of pesticidal genes. Additionally, genes linked to plant growth-promoting traits (e.g., asbA, ipdC, and accd) were identified. This omics-guided strategy supports efficient Bt strain selection and broader application in sustainable agriculture.},
}

@article {pmid40856861,
year = {2025},
author = {Saif, M and Ahmed, V and Ahmed, S and Rizvi, SA and Yadav, RN and Haq, QMR},
title = {High prevalence of co-trimoxazole and carbapenem resistance among uropathogenic bacteria from a community hospital in New Delhi, India.},
journal = {Molecular biology reports},
volume = {52},
number = {1},
pages = {849},
pmid = {40856861},
issn = {1573-4978},
abstract = {BACKGROUND: Urinary tract infections (UTI) caused by multidrug-resistant bacteria are a serious concern worldwide. The problem is exacerbated by the rapid rise of resistance to antibiotics, including co-trimoxazole and carbapenem. This study investigates the prevalence of co-trimoxazole and carbapenem resistance among bacteria causing UTI from a community hospital in New Delhi. METHODS: Antibiotic susceptibility tests were carried out by Kirby-Bauer disc diffusion and broth microdilution method. Molecular detection of antibiotic-resistant genes was done by PCR. Plasmid-mediated horizontal gene transfer and biofilm studies were performed by conjugation assay and crystal violet assay, respectively. FINDINGS: Phenotypic screening of 141 non-duplicate bacterial isolates obtained from urine samples showed co-trimoxazole resistance in 72% isolates (n = 101). Among 101 co-trimoxazole resistant isolates, 63 were phenotypically positive for carbapenem resistance. The isolates were identified as Escherichia coli (n = 69), Klebsiella pneumoniae (n = 15), Streptococcus dysgalactiae (n = 5), Citrobacter spp. (n = 3), Pseudomonas aeruginosa (n = 3), Staphylococcus aureus (n = 3), Klebsiella oxytoca (n = 1), Serratia fonticola (n = 1) and Proteus mirabilis (n = 1). Co-trimoxazole resistant genes sul1, sul2, dfrA1, dfrA5, dfrA7, dfrA12, and dfrA17 were detected in 75, 28, 29, 23, 60, 63, and 8 isolates, respectively. Carbapenem resistance genes blaNDM, blaOXA-48, blaKPC, and blaIMP were amplified in 36, 77, 8, and 27 isolates, respectively using plasmid DNA as the template. CONCLUSION: This study provides useful data on an alarming rise in co-trimoxazole and carbapenem resistance among bacteria causing UTI. Conjugation assay confirmed horizontal transfer of plasmid-borne resistance genes. Furthermore, some of these isolates were resistant to nitrofurantoin and fosfomycin, the last resort antibiotics for treating UTI.},
}

@article {pmid41222715,
year = {2025},
author = {Almutawif, YA and Khan, NU},
title = {Gut microbiome dysbiosis and antimicrobial resistance in the Middle East: a converging public health crisis in conflict and fragile settings.},
journal = {Archives of microbiology},
volume = {208},
number = {1},
pages = {15},
pmid = {41222715},
issn = {1432-072X},
abstract = {The Middle East is confronting a converging public health crisis as gut microbiome dysbiosis and antimicrobial resistance (AMR) amplify in conflict and fragile settings, driven by war, displacement, and systemic healthcare collapse. This review examines the bidirectional relationship between disrupted gut microbiota and escalating AMR, particularly among vulnerable refugee populations and war-affected communities. Key findings reveal alarming resistance rates in ESKAPE pathogens (e.g., Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp), exacerbated by unregulated antibiotic use, malnutrition, and poor sanitation. Dysbiosis fosters AMR through loss of colonization resistance and horizontal gene transfer, while conflict-related healthcare breakdowns—such as empiric antibiotic overuse and absent diagnostics—accelerate resistance spread. Refugee camps, with overcrowding and contaminated water, emerge as critical AMR hotspots. Urgent interventions are needed, including microbiome restoration therapies (e.g., probiotics and faecal microbiota transplantation (FMT), rapid diagnostic tools, and integrated One Health surveillance. Moreover, the increasing trend of AMR is further amplified by the COVID-19 pandemic, which led to widespread antibiotic use and disrupted healthcare services. Review emphasises the importance of regional policy coordination, targeted humanitarian aid focused on microbiome health, and global advocacy to mitigate this crisis, which poses a threat to both local and international health security. Without action, the intersection of dysbiosis and AMR will deepen health inequities in conflict zones, with far-reaching consequences.},
}

@article {pmid41718947,
year = {2026},
author = {AlJerf, A and Maad, AH and Ukaogo, PO and Aljerf, L and Ajong, AB and Alajlani, M},
title = {Antimicrobial Armageddon: The Professional Guide to Conquering Antibiotic Resistance.},
journal = {Probiotics and antimicrobial proteins},
volume = {},
number = {},
pages = {},
pmid = {41718947},
issn = {1867-1314},
abstract = {Antibiotic resistance has accelerated into a critical global health emergency, undermining the effectiveness of modern medicine and increasing the burden of severe, persistent, and difficult-to-treat infections. This review synthesizes current evidence on the biological, clinical, and public health dimensions of resistance and highlights the major drivers behind its rapid expansion. Recent epidemiological data reveal substantial increases in mortality associated with resistant bloodstream, respiratory, and intra-abdominal infections, emphasizing the urgency of coordinated intervention. Mechanistic analyses demonstrate how horizontal gene transfer (HGT), mutational adaptation, biofilm formation, efflux systems, and enzymatic drug modification collectively strengthen bacterial survival. In parallel, persistent and tolerant cell populations further complicate therapeutic outcomes by enabling recurrent and chronic infections. Despite these challenges, several promising countermeasures have emerged. Advances in antimicrobial stewardship, drug repurposing, bacteriophage-based strategies, immunotherapies, and nanotechnology offer new avenues to restore or enhance antimicrobial efficacy. Innovative approaches—such as targeting novel metabolic pathways, disrupting virulence networks, and employing engineered phage systems—represent a growing frontier in drug development. Collectively, these insights highlight the importance of integrating molecular innovation, optimized clinical practices, and global surveillance as complementary strategies to mitigate the progression of antimicrobial resistance. Finally, this review acknowledges limitations related to the focus on bacterial pathogens, while recognizing that antifungal and antiviral resistance present parallel, distinct challenges in global health.},
}

@article {pmid41805848,
year = {2026},
author = {Nada, MAL and Asejo, AB and Joloro, MJG and Chin, RAD and Reterta, MCC and Collado, ARG and Casidsid, JYO and Tejada, AJP and Ancla, JB and Gestuveo, RJ},
title = {Genome characterization and receptor-binding protein identification of Klebsiella phage vB_VIPKPNMC05, a member of a novel viral family Pituviridae.},
journal = {Archives of virology},
volume = {171},
number = {4},
pages = {},
pmid = {41805848},
issn = {1432-8798},
support = {LFP-EBD-2021-02//Department of Science and Technology Grants-In-Aid (GIA) Program/ ; },
abstract = {Klebsiella pneumoniae is an opportunistic pathogen and a leading cause of antimicrobial-resistant infections in the Philippines. Here, we report the genome sequence of Klebsiella phage vB_VIPKPNMC05, which targets a multidrug-resistant (MDR) K. pneumoniae strain with capsule type K8. VIPKPNMC05, isolated from environmental water, has a siphovirus morphology and exhibits a broad lytic activity against several strains of K. pneumoniae, K. quasipneumoniae, Pseudomonas aeruginosa, and Escherichia coli. The linear double-stranded DNA genome (34,476 bp; 51.0% G + C content) encodes 58 protein-coding sequences (CDS), 37 of which are involved in phage morphogenesis, DNA replication, transcription regulation, and host lysis. Notably, a receptor-binding protein (RBP) with a putative depolymerase (Dpo) was identified. Structural prediction using AlphaFold 3 showed that the tailspike protein (TSP19) forms a homotrimer structure with a conserved C-terminal pectin lyase domain. The TSP module is conserved among Enterobacteriaceae-infecting phages and may have been acquired through horizontal gene transfer. Whole-genome comparisons revealed 52–54% similarity to known phages, suggesting that VIPKPNMC05 represents a distinct lineage. Based on taxonomic analysis, we propose that VIPKPNMC05 belongs to a novel phage family, Pituviridae. The absence of virulence, toxin, and antimicrobial resistance genes, along with its broad host range and lytic lifestyle, suggests possible therapeutic and biotechnological potential of VIPKPNMC05. To our knowledge, this is the first report of a newly discovered phage family from the Philippines, underscoring the importance of local phage bioprospecting for therapeutic applications.},
}

@article {pmid41998453,
year = {2026},
author = {Harini, AC and Sundaresan, AK and Ramakrishnan, J},
title = {Klebsiella pneumoniae in the global AMR: resistance mechanisms and genomic adaptation.},
journal = {World journal of microbiology & biotechnology},
volume = {42},
number = {5},
pages = {},
pmid = {41998453},
issn = {1573-0972},
abstract = {Antimicrobial Resistance (AMR) represents a defining crisis of modern healthcare, severely limiting therapeutic options and driving a global increase in clinical mortality. Central to this crisis is Klebsiella pneumoniae, a ubiquitous gut commensal that has evolved into a formidable opportunistic pathogen through its remarkable ability to transition from a harmless organism to a hypervirulent, Multidrug-Resistant (MDR) threat. This review examines that pathogenic transition, emphasizing the dangerous convergence of virulence and resistance traits particularly within carbapenem-resistant lineages. The bacterium leverages an expansive “open” pangenome and immense genetic plasticity to act as a primary trafficker of AMR genes. We detail the molecular mechanisms underlying resistance across nearly all antibiotic classes including β-lactams, aminoglycosides, and last-resort polymyxins driven by enzymatic degradation, target modification, and sophisticated efflux systems. Beyond clinical antibiotic pressure, the review explores how non-antibiotic drivers, such as environmental stressors, biocide exposure, and heavy metals, accelerate AMR evolution through cross-resistance and novel epigenetic adaptations. The rapid dissemination of these resistance determinants is facilitated by a robust toolkit of Horizontal Gene Transfer (HGT), including transposons, integrons, plasmid replicons, and bacteriophage-mediated transduction. Finally, this review evaluates the current therapeutic landscape, addressing the challenges of the drug development pipeline while highlighting emerging interventions such as novel β-lactam/β-lactamase inhibitor combinations, phage therapy, and anti-virulence strategies. Understanding this interplay between genomic evolution and ecological drivers is critical for designing a unified stewardship framework and effective interventions to curb the global AMR crisis.},
}

@article {pmid42281424,
year = {2026},
author = {Garland, S and Orr, VT and Hall, JPJ and Harrison, E},
title = {Invasive plasmids as ecosystem engineers-from mechanism to application.},
journal = {Essays in biochemistry},
volume = {},
number = {},
pages = {},
doi = {10.1042/EBC20250040},
pmid = {42281424},
issn = {1744-1358},
support = {APP37189//UKRI | Biotechnology and Biological Sciences Research Council (AFRC)/ ; NE/X009971/1//UKRI | Natural Environment Research Council (NERC)/ ; MR/W02666X/1//UKRI | Medical Research Council (MRC)/ ; },
abstract = {Horizontal gene transfer, mediated by mobile genetic elements such as conjugative plasmids, is recognised as a major driver of bacterial innovation. While predominantly explored in the context of change within individual strains and species, the broad host ranges of many plasmids mean that they can invade not just lineages but communities. This has far-reaching implications for both the fate of the plasmid and our understanding of bacterial adaptation, as well as applications for the functional engineering of microbial communities. In comparison to single-strain systems, in which plasmid invasion is largely determined by a now well-defined set of parameters-conjugation rate, fitness cost of carriage, and segregation loss-the spread of plasmids into communities is vastly more complex: governed by the wide range of dynamics within strains, but also by community dynamics, spatial heterogeneity, and the interactions between strain- and community-level selection. Here, we review the processes by which plasmids can invade communities and discuss how community complexity both constrains and facilitates plasmid spread. We further explore how this mechanistic understanding can be harnessed to enhance microbial community function.},
}

@article {pmid42283811,
year = {2026},
author = {Costanzo, M and Di Gregorio, L and Tabacchioni, S and Bevivino, A and Visca, A},
title = {Mobile Genetic Elements as Key Drivers of Bacterial Evolution and Adaptation in Agroecosystems.},
journal = {Microbial ecology},
volume = {},
number = {},
pages = {},
doi = {10.1007/s00248-026-02803-5},
pmid = {42283811},
issn = {1432-184X},
abstract = {Mobile genetic elements (MGEs), including plasmids, transposons, integrative and conjugative elements, and phage-derived sequences, are central drivers of bacterial evolution in agroecosystems. By enabling horizontal gene transfer, MGEs allow soil- and plant-associated bacteria to rapidly acquire complex functional traits, facilitating adaptation to fluctuating environmental conditions and different agricultural management practices. In agricultural soils, MGEs underpin key microbial functions such as nutrient acquisition and cycling, stress tolerance, rhizosphere competence, and interactions with plant hosts, thereby influencing soil fertility and crop performance. Selective pressures in agroecosystems extend beyond antimicrobial exposure and include fertilizers, pesticides, plant defense compounds, recurrent biotic and abiotic stress, as well as high-yielding crop varieties. These pressures generate co-selection dynamics that shape mobilome composition and activity, linking traits such as resistance, pathogenicity, and biocontrol to broader ecological functions relevant to plant health. Rather than acting as exceptional genetic entities, MGEs form a dynamic and environmentally responsive genetic network that enables rapid ecological tuning while preserving core genome stability. Comparative genomics has revealed that major lifestyle transitions in agroecosystem-associated bacteria, from free-living to commensal, mutualistic, or pathogenic states, are frequently mediated by the gain and loss of genomic islands and other MGEs. This review synthesizes the latest research on the ecological functions and evolutionary dynamics of MGEs in agroecosystems and explores how mobilome-informed approaches can support microbial-based strategies for sustainable agriculture.},
}

@article {pmid42284196,
year = {2026},
author = {Benigno, V and Carraro, N and Gardet, M and Budny, H and van der Meer, JR},
title = {Horizontal transfer of ICEclc-like elements in Pseudomonas aeruginosa clinical isolates.},
journal = {Journal of bacteriology},
volume = {},
number = {},
pages = {e0000926},
doi = {10.1128/jb.00009-26},
pmid = {42284196},
issn = {1098-5530},
abstract = {Integrative and conjugative elements (ICEs) are widespread autonomous mobile DNA within bacterial chromosomes. ICEs contain the genes necessary for excision from the chromosome, conjugative transfer to a new recipient cell, and chromosomal reintegration. They can also carry accessory genes that, while not essential for transfer, confer adaptive phenotypes to the host, contributing to host survival under stressful or changing conditions. Genome studies have indicated that Pseudomonas aeruginosa clinical isolates carry a wide range of related ICEs with adaptive genes enriched for heavy metal resistance and efflux systems; however, their mobility has remained understudied. Here, we studied the activation and transfer mechanisms of a representative subset of ICEclc-type elements. We found that ICE excision could be induced in P. aeruginosa by ectopic expression of BisDC, the known master regulator of ICEclc activation, pointing to a similar regulatory cascade. A number of elements could be transferred to P. putida, where they conferred increased tolerance to specific heavy metals. We also assessed ICE excision rates in response to different classes of stressors using qPCR-based quantification. Sub-lethal copper exposure significantly increased ICE excision rates in several P. aeruginosa strains, although this response was strongly strain-dependent and absent in isolates with enhanced copper tolerance, highlighting the importance of host background. Despite elevated excision, copper did not stimulate ICE transfer or induce conjugation gene expression, indicating that ICE excision and conjugation can be uncoupled processes. Transcriptomic analyses revealed strain-specific regulatory responses to copper stress, including differential activation of metal-responsive regulators, oxidative stress pathways, and virulence-associated systems.IMPORTANCEIntegrative and conjugative elements (ICEs) play a major role in bacterial adaptation by mediating horizontal gene transfer; however, the environmental cues governing their activation remain poorly understood. Here, we demonstrate that ICEclc-type elements in Pseudomonas aeruginosa are transferable at low frequencies and that their excision rates can be selectively increased by specific stress conditions, notably copper exposure and hypoosmotic stress. Our findings reveal that ICE excision and conjugative transfer can be uncoupled and are strongly influenced by host genetic background, underscoring the complexity of ICE regulation. This work aimed to explore whether clinical conditions or antimicrobial treatment could inadvertently promote ICE-mediated gene transfer, with implications for understanding the evolution of antibiotic resistance and virulence.},
}

@article {pmid42286276,
year = {2026},
author = {Wójcicki, M and Cieślik, M and Górski, A and Jończyk-Matysiak, E},
title = {Giving Antibiotics a Second Chance: Evolutionary Trade-Offs and Phage-Driven Restoration of Antibiotic Susceptibility.},
journal = {BioDrugs : clinical immunotherapeutics, biopharmaceuticals and gene therapy},
volume = {},
number = {},
pages = {},
pmid = {42286276},
issn = {1179-190X},
abstract = {Antimicrobial resistance poses a critical and escalating threat to global public health, driven by the widespread and often unjustified use of antibiotics and the rapid dissemination of resistance determinants. With the antibiotic discovery pipeline largely depleted, alternative and complementary strategies are urgently needed to preserve the effectiveness of existing antimicrobials. Bacteriophages-viruses that specifically infect bacteria-have re-emerged as promising tools not only for direct bacterial eradication but also for reshaping bacterial evolutionary trajectories. This review examines the concept of phage-driven restoration of antibiotic susceptibility, focusing on evolutionary trade-offs that arise when bacteria adapt to phage pressure. Resistance to bacteriophages frequently involves modifications of surface structures, capsules, or efflux systems, changes that often incur fitness costs manifested as reduced virulence, impaired biofilm formation, or increased antibiotic sensitivity. Experimental studies and clinical case reports demonstrate that phage-antibiotic synergy can suppress bacterial growth more effectively than monotherapy, limit resistance emergence, and resensitize multidrug-resistant pathogens to previously ineffective antibiotics. Particular attention is given to mechanisms involving efflux pump targeting, capsule loss, biofilm disruption, and temperate phage-antibiotic interactions. In addition, emerging strategies that combine bacteriophages with CRISPR-Cas systems enable precise targeting and removal of resistance genes, offering a highly selective means to restore antibiotic efficacy and curb horizontal gene transfer. Together, these findings highlight bacteriophages as powerful evolutionary and therapeutic tools capable of giving antibiotics a "second chance". Integrating phage-based approaches into antibiotic stewardship frameworks may represent a sustainable path forward in combating multidrug-resistant bacterial infections.},
}

@article {pmid42287895,
year = {2026},
author = {Yao, Z and Lin, G and Liu, Y and Zhang, J},
title = {Mechanisms for the phytohormone-elevated performance of a continuous-flow baffled cyanobacterial photo-bioreactor for antibiotic removal and lipid production.},
journal = {Water research},
volume = {303},
number = {},
pages = {126283},
doi = {10.1016/j.watres.2026.126283},
pmid = {42287895},
issn = {1879-2448},
abstract = {A mixture of Synechococcus sp., Chroococcus sp., and Synechocystis sp. was immobilized in indole-3-acetic acid (IAA)-supplemented calcium alginate beads and then placed into a four-compartment baffled photo-bioreactor. A 30-day continuous-flow treatment of secondary effluent wastewater using this system achieved removal rates of 74.08-85.12% for COD, 87.52-96.89% for TN, 95.36-99.26% for TP, 84.02-88.36% for cefalexin, 67.15-75.57% for erythromycin, 91.17-96.05% for oxytetracycline, and 74.76-78.87% for norfloxacin. Chroococcus sp. contributed the most to pollutant removal, with its abundance negatively correlated with the concentrations of all pollutants. Bacterial colonization within cyanobacterial beads, upregulated genes involved in signal transduction, quorum sensing, and biofilm formation, as well as correlations between cyanobacteria and seven bacterial genera (Acidovorax, Chitinophaga, Massilia, Algoriphagus, Chryseobacterium, Comamonas, and Candidatus) together confirmed the formation of a cyanobacteria-bacteria consortium. Efficient pollutant removal was attributed to the high cyanobacterial biomass stimulated by IAA and the activation of genes related to stress response, the TCA cycle, oxidative phosphorylation, and pollutant metabolism in bead microorganisms. Reduced abundances of antibiotic resistance genes in the effluent may result from activated mismatch repair pathway and suppressed horizontal gene transfer. Antibiotics, the symbiotic bacterium Azospirillum, and IAA jointly stimulated cyanobacterial growth and lipid accumulation, contributing to a high cyanobacterial lipid productivity of 47.59-51.82 mg/(L·d), mainly through the upregulation of genes involved in the Calvin cycle, pentose phosphate pathway, and fatty acid biosynthesis. Overall, this study provides a sustainable strategy integrating pollutant removal, resistance control, and resource recovery.},
}

@article {pmid42287910,
year = {2026},
author = {Li, H and Li, Y and Zhang, Z and Li, X and Zhao, K and Fan, Z and Liu, K},
title = {The ablation cycle drives glacier microbiome dynamics and downstream dissemination risk of the resistome.},
journal = {Journal of hazardous materials},
volume = {514},
number = {},
pages = {142686},
doi = {10.1016/j.jhazmat.2026.142686},
pmid = {42287910},
issn = {1873-3336},
abstract = {Glacial ecosystems on the Tibetan Plateau undergo pronounced hydrological shifts across the glacial ablation cycle, driven by the onset and retreat of the Indian summer monsoon. To elucidate how transitions between four distinct hydrological ablation stages (pre-ablation, early ablation, late ablation, and frozen) shape microbial community structures and antibiotic resistance gene (ARG) profiles, we analyzed 112 samples collected across four stages from multiple glacier catchments on the southeastern Tibetan Plateau using metagenomic sequencing. Our results indicated that warmer stages favored thermotolerant Proteobacteria and reduced overall community diversity and evenness. ARG abundances exhibited ablation-dependent fluctuations, with Betaproteobacteria identified as predominant potential hosts. Furthermore, ARGs and virulence factors associated with mobile genetic elements were enriched during early and late ablation stages relative to the frozen stage, suggesting elevated potential for horizontal gene transfer coinciding with peak meltwater discharge. Notably, while upstream meltwaters generally exhibited higher ARG abundances, the upstream-downstream disparity tended to diminish from the pre-ablation to the late ablation stage, likely reflecting enhanced microbial mixing driven by glacier melt. Together, these findings reveal that glacier meltwater microbiomes are primarily shaped by ablation dynamics rather than spatial heterogeneity. More importantly, dynamics across the glacial ablation cycle drive shifts in meltwater hydrology that facilitate the downstream environmental mobility of glacial resistomes, posing growing antimicrobial resistance risks within the One Health framework.},
}

@article {pmid42291119,
year = {2026},
author = {Park, J and Jang, KB and Kang, MG and Kyung, J and Yoon, J and Ryu, S and Kim, Y},
title = {Comparative pangenome analysis of methanogenic archaea from diverse ecosystems reveals potential targets for methane mitigation in rumen microbiome.},
journal = {Journal of animal science and technology},
volume = {68},
number = {3},
pages = {935-953},
pmid = {42291119},
issn = {2055-0391},
abstract = {Rumen methanogenesis is a major biological contributor to methane emissions in ruminants, yet the extent to which functional markers align with taxonomic relationships and how genome content varies across habitats, remains poorly resolved. In this study, we integrated broad phylogenetic frameworks with pangenome-resolved analysis to characterize methanogenic archaea from diverse ecosystems, including seawater, freshwater, sewage, rumen, human gut, soil, and cockroach sources. By combining these insights with pangenome reconstruction and KEGG-based pathway mapping of methanogenesis, we reveal key evolutionary and functional patterns. Notably, phylogenies based on 16S rRNA and mcrA genes showed limited concordance: only two clades exhibited overlap between trees, with most clustering patterns lacking environmental specificity. This discrepancy reflects the deep conservation of 16S rRNA compared with the evolutionary plasticity of mcr genes, shaped by lateral gene transfer, gene loss, and pathway modularity. The pangenome comprised of 8,695 orthogroups across 71 genomes, with core and soft-core genes enriched in translation, amino acid metabolism, and coenzyme biosynthesis, while the shell contained many poorly annotated orthogroups, highlighting annotation gaps in archaeal genomes. KEGG analysis revealed habitat-specific signatures: rumen methanogens were notably depleted in genes of the acetyl-CoA pathway, whereas human gut methanogens lacked key cofactor biosynthesis modules, including those for coenzymes M, B, F420, and methanofuran. From rumen-derived shotgun metagenomes, we identified 53 methane-producing, 4 canonical methanogenic, 10 potential competitor, and 1 methanotrophic metagenome-assembled genomes based on functional gene content. Competitor candidates included nitrate-reducing and Wood-Ljungdahl pathway-utilizing acetogens, suggesting hydrogen redirection under high-hydrogen or inhibitor conditions. These findings support a functional marker strategy that integrates 16S rRNA with pathway-specific genes and a pangenome framework to enhance ecological interpretations of methanogens and to prioritize potential targets for methane mitigation in ruminants.},
}

@article {pmid42292220,
year = {2026},
author = {Ge, J},
title = {Functional redundancy as a stabilizing principle in bacterial communities under antibiotic perturbation: mechanisms, trade-offs, and emerging frameworks.},
journal = {Frontiers in medicine},
volume = {13},
number = {},
pages = {1834295},
pmid = {42292220},
issn = {2296-858X},
abstract = {The widespread use of antibiotics has severely disrupted the structure of microbial communities, but the responses of these communities vary in different environments. Interestingly, even when the species composition changes, some microbial communities can still maintain crucial functions, a phenomenon known as "decoupling of structure and function." Among them, functional redundancy (FR) - the characteristic that multiple microorganisms perform the same ecological function - is the key mechanism for maintaining this stability. This review focuses on how functional redundancy may enhance microbial community resilience under antibiotic perturbation. We first start from the insurance hypothesis and the YAS (yield - acquisition - stress) framework to explain the ecological principles behind functional redundancy, and explain how microorganisms allocate resources and make trade-offs in different environments. We systematically analyze the multi-level defense strategies of microorganisms at five levels, including: ecological niche differentiation at the species level, horizontal transfer of resistance genes at the genetic level, cross-feeding reconstruction of metabolic networks, dormancy strategies at the temporal dimension (seed bank), and population regulation mediated by bacteriophages. Methodologically, we review metatranscriptomic approaches for distinguishing active signals from residual DNA, structural entropy algorithms for inferring FR, and AI-based tools for identifying latent resistance genes. Evidence from ecosystems such as the gut, respiratory tract, soil, and wastewater suggests the broad relevance of functional redundancy, although its stabilizing effect depends on antibiotic type, exposure duration, initial community composition, and ecological context. Finally, we explore the application prospects of this principle in the construction of synthetic communities and the optimization of fecal microbiota transplantation, and point out the evolutionary costs that may accompany maintaining functional redundancy, which is an important challenge that future research needs to address.},
}

@article {pmid42292747,
year = {2026},
author = {Fan, F and Shi, Q and Chen, G and Zhan, H and Deng, S and Peng, Y and Wei, L},
title = {Meropenem stress drives lipid remodeling and resistance gene dissemination via outer membrane vesicles in carbapenem-resistant Klebsiella pneumoniae.},
journal = {Current research in microbial sciences},
volume = {11},
number = {},
pages = {100616},
pmid = {42292747},
issn = {2666-5174},
abstract = {Carbapenem-resistant Klebsiella pneumoniae (CRKP) has emerged as a critical global health threat, fueled by escalating antibiotic resistance rates among clinical isolates. This study investigates the adaptive responses of CRKP to meropenem, a last-line β-lactam antibiotic, with a focus on the role of outer membrane vesicles (OMVs) in resistance evolution. Under meropenem stress, CRKP exhibited significant upregulation of total lipid content within OMVs (CRKP-OMVs), particularly enriched in glycerophospholipids and sphingolipids to enhance bacterial membrane integrity. Notably, CRKP-OMVs function as critical vehicles for the carbapenemase gene bla KPC-2 . Furthermore, meropenem exposure significantly augments their horizontal gene transfer (HGT) efficiency. Compared to control OMVs, these drug-induced vesicles facilitated a 3.52-fold and 12.08-fold increase in bla KPC-2 dissemination into carbapenem-susceptible K. pneumoniae and Escherichia coli recipients, respectively. Proteomic profiling revealed meropenem-driven upregulation of efflux machinery (e.g., PET family inner membrane protein YccS, multidrug resistance outer membrane channel MdtQ) and lipid transporters (LptB, LplT, phospholipid-lipopolysaccharide ABC transporter). These findings demonstrate that meropenem exposure modulates OMVs' proteolipid composition and enhances biofilm formation, while simultaneously promoting OMV-mediated dissemination of resistance genes through their function as mobile genetic vectors under therapeutic pressure, suggesting a potential defensive mechanism against antibiotic penetration.},
}

@article {pmid42294647,
year = {2026},
author = {Guzel, M and May, F and Buchan, A},
title = {Mobile genetic elements shape the evolution and adaptation of the marine Sulfitobacter genus.},
journal = {mSystems},
volume = {},
number = {},
pages = {e0047926},
doi = {10.1128/msystems.00479-26},
pmid = {42294647},
issn = {2379-5077},
abstract = {UNLABELLED: Mobile genetic elements (MGEs) are essential for facilitating horizontal gene transfer and play crucial roles in the evolution and adaptive capabilities of bacterial species. Here, we analyzed closed genomes from the marine Sulfitobacter genus to assess plasmid contributions to ecological adaptability and evolutionary diversification. Our analysis of 153 Sulfitobacter plasmids from 36 strains representing 8 species shows extensive plasmid conservation within species (e.g., >95% nucleotide identity for flagellar plasmids) alongside significant mosaicism across 60% of plasmids. Insertion sequences (IS) elements are nearly ninefold more concentrated on plasmids relative to chromosomes, suggestive of active genetic exchange in this replicon class. Network analysis identified 14 primary plasmid clusters, with species-specific conservation patterns and evidence of inter-species gene transfer. In Sulfitobacter pontiacus strain CB2047, we discovered chromosomal integration of a 280 kb plasmid encoding a toxin-antitoxin system, rrn operon, as well as a chromosomal partitioning system. These findings demonstrate that plasmids function as key drivers of evolution and adaptation in Sulfitobacter, serving as both repositories of conserved adaptive traits and platforms for ongoing genetic innovation.

IMPORTANCE: Plasmids are increasingly recognized as crucial drivers of bacterial evolution and adaptation, yet their roles in shaping marine microbial communities are poorly understood. Here, we provide a comprehensive analysis of plasmid diversity and evolution within Sulfitobacter, a broadly distributed and metabolically versatile marine bacterial genus, in which ~15% of genome content is plasmid-encoded. We propose that Sulfitobacter plasmids serve dual evolutionary roles: maintaining highly conserved species-specific traits essential for survival (such as flagellar motility and biofilm formation), while simultaneously functioning as platforms for genetic innovation through extensive horizontal gene transfer. The discovery of a large plasmid integrated into the chromosome of one strain highlights that episomal elements can transition to stable chromosomal inheritance in this genus. These findings advance our understanding of how marine bacteria balance genomic stability with adaptive flexibility, providing insights applicable to microbial evolution in dynamic ocean environments.},
}

@article {pmid42294719,
year = {2026},
author = {Regan, MR and McDevitt, CJ and Robinson, LR and Issifou, S and Wadsworth, CB},
title = {Put your money where your mouth is: surveillance of antibiotic resistance within the commensal Neisseria.},
journal = {Microbiology spectrum},
volume = {},
number = {},
pages = {e0072526},
doi = {10.1128/spectrum.00725-26},
pmid = {42294719},
issn = {2165-0497},
abstract = {Commensal Neisseria species are major reservoirs of adaptive genetic variation, including antimicrobial resistance, for their pathogenic relatives, yet they remain poorly characterized. This gap limits our ability to anticipate resistance mechanisms that may ultimately emerge in Neisseria gonorrhoeae and Neisseria meningitidis. Here, we analyzed 166 novel commensal Neisseria isolates collected from 31 study participants and measured minimum inhibitory concentrations (MICs) for seven antimicrobials: azithromycin, cefixime, ceftriaxone, ciprofloxacin, doxycycline, penicillin, and gentamicin. Resistance, defined using the Clinical and Laboratory Standards Institute guidelines, was highly prevalent for azithromycin (76%) and doxycycline (52%), while no resistance to gentamicin was observed. High-level doxycycline resistance was always associated with the inheritance of tetM. Reduced susceptibility to azithromycin was linked to an MtrD K823E substitution, and reduced susceptibility to ciprofloxacin was associated with GyrA T91I (Neisseria subflava) or S91V (Neisseria mucosa). Across all antimicrobials, MICs varied widely, indicating the presence of additional modulating mutations. Finally, the genetic determinants underlying low-level doxycycline resistance and reduced penicillin susceptibility remain unresolved. Overall, here, we continue to build on the foundation of surveillance efforts in the commensal Neisseria and continue to flesh out what is known and unknown about this early warning system-or canary in the coal mine-for emerging resistance and clinically consequential evolution in pathogenic Neisseria.IMPORTANCECommensal Neisseria species constitute a vast and dynamic reservoir of genetic diversity that can be exchanged with pathogenic relatives, Neisseria gonorrhoeae and Neisseria meningitidis. However, these commensals remain substantially undercharacterized, limiting our ability to anticipate the evolutionary trajectories of antimicrobial resistance in clinically important species. By systematically analyzing commensal isolates and defining phenotypic resistance patterns alongside their genetic determinants, this study, and others like it, function as an early warning system for the emergence and spread of antimicrobial resistance. The high prevalence of azithromycin and doxycycline resistance, identification of specific mutations associated with reduced susceptibility, and evidence of additional unexplained contributors to minimum inhibitory concentration variation highlight both known and cryptic pathways of adaptation. These findings underscore the necessity of integrating commensal surveillance into resistance monitoring frameworks, improving our capacity to forecast clinically consequential evolution and to inform stewardship, diagnostics, and therapeutic development before resistance becomes entrenched in pathogenic Neisseria.},
}

@article {pmid42294728,
year = {2026},
author = {Mao, Z and Jiang, M and Zhao, Z and Xu, S and Wang, H and Chen, K and Duan, J and Chen, Z and He, D and Xing, P and Wu, QL},
title = {Biofilm-forming traits enrich the plasmid diversity and functional potential in particle-attached bacteria in coastal ecosystems.},
journal = {Microbiology spectrum},
volume = {},
number = {},
pages = {e0046026},
doi = {10.1128/spectrum.00460-26},
pmid = {42294728},
issn = {2165-0497},
abstract = {UNLABELLED: Planktonic microorganisms play a central role in aquatic biogeochemical processes and are commonly divided into particle-attached (PA) and free-living (FL) fractions. Although these two lifestyles differ in ecological strategy, the contribution of plasmids to their niche differentiation remains poorly resolved. Here, we conducted a plasmid-centric metagenomic analysis of two anthropogenically impacted coastal ecosystems in South China, the Pearl River Estuary (PRE), and Daya Bay (DYB), to determine the environmental and biological drivers of plasmid diversity, and their functional potenitial. We found that plasmid diversity was jointly shaped by different fractions and environmental stressors. The PA fraction contained significantly higher plasmid abundance and richness than the FL fraction, and was enriched in multifunctional and conjugative plasmids. These plasmids were associated with genes adapting to the PA lifestyle or microenvironments, suggesting linkage between particle attachment and plasmid maintenance. Structural equation modeling indicated that different fractions shaped plasmid diversity primarily through biofilm-forming genes. Along an anthropogenic gradient from DYB to PRE, increasing pollution levels were accompanied by higher plasmid diversity and greater abundances of antibiotic and metal resistance genes. Plasmid diversity was strongly correlated with resistance gene abundance. The enrichment of transferable plasmids in the PA fraction, where cell densities are high and intercellular distances are close, suggested that particle-associated habitats favor genetic exchange and the persistence of resistance traits. Together, these results demonstrate that particle-associated microbial communities represent key reservoirs of plasmid diversity and resistance potential in coastal ecosystems and highlight the combined influence of lifestyles and anthropogenic stress on plasmid-mediated microbial adaptation.

IMPORTANCE: Plasmids play an important role in microbial adaptation by mediating horizontal gene transfer, yet the ecological contexts that favor their persistence and diversification in natural environments remain poorly understood. This study showed that particle-attached microbial communities in coastal waters harbored substantially higher plasmid diversity and resistance potential than free-living communities, and that this enrichment is strongly linked to biofilm-associated traits. By demonstrating how particulate habitats and pollution gradients jointly shape plasmid diversity and resistance gene abundance, our findings identify particle-associated microenvironments as critical reservoirs for plasmid-mediated functions in coastal ecosystems. These results advance understanding of how microbial lifestyle and human activities influence microbial evolution and the environmental dissemination of resistance traits.},
}

@article {pmid42294936,
year = {2026},
author = {Lombardino, JM and Falbel, TG and Dewey, CN and Burton, BM},
title = {High-resolution genomic analysis reveals abundant mosaic outcomes of bacterial natural transformation independent of MutS-mediated mismatch repair.},
journal = {mBio},
volume = {},
number = {},
pages = {e0044426},
doi = {10.1128/mbio.00444-26},
pmid = {42294936},
issn = {2150-7511},
abstract = {The nature and breadth of horizontal gene transfer outcomes specific to natural transformation remain elusive. We present a genome-scale analysis of location-specific information associated with single-round transformation events in Bacillus subtilis. Using distributed selectable markers to remove location bias, we found transformant genomes often contained multiple discontinuous segments of donor sequence in close proximity. These highly mosaic sites span multiple length scales, with an abundance of shorter segments. We found that the small segments scale with the length of the nearest stretch of perfect homology, and these segments defy minimal, efficient homologous recombination rules. Sites of transformation and their associated intervening recipient sequences were not distinguished by overall percent identity, GC content, or median gene expression. Mismatch repair activity by MutS also failed to explain the breadth and frequency of mosaic patches. High-resolution mapping of donor and recipient alleles across sites of transfer demonstrates that natural transformation can contribute a breadth of allelic diversity, especially within short, clustered patches of genetic exchange. These observations point to a need to further investigate the complex mechanisms that drive distinct outcomes of natural transformation.IMPORTANCESeveral works have suggested the potential for discontinuity for donor DNA in transforming DNA. This work developed robust bioinformatic and genomic approaches to assess the full breadth of exchange between divergent genomes during natural transformation. The results demonstrate that simplistic sequence and expression-based associations are not sufficient to explain highly variable transformation outcomes. Similarly, transformant genomes are frequently incongruent with previously defined rules for homology-mediated recombination. MutS-mediated mismatch repair, a frequently proposed contributor to mosaic recombination, is also insufficient to explain discontinuity. Therefore, widespread molecular mechanisms intrinsic to recombination have the potential to generate significant genetic diversity during transformation, ranging from the scale of individual alleles to full operons. These results further reinforce the role of natural transformation in shaping genetic diversity within bacterial populations.},
}

@article {pmid42295605,
year = {2026},
author = {Olymon, K and Bhattacharjee, I and Roy, N and Rs, S and Dey, U and Teronpi, V and Kumar, A},
title = {Genome-wide analysis of biosynthetic gene clusters reveals hidden metabolic diversity in bacterial fish pathogens.},
journal = {World journal of microbiology & biotechnology},
volume = {42},
number = {7},
pages = {},
pmid = {42295605},
issn = {1573-0972},
mesh = {*Multigene Family ; Animals ; *Fishes/microbiology ; *Genome, Bacterial ; *Bacteria/genetics/metabolism/classification ; Phylogeny ; *Biosynthetic Pathways/genetics ; Secondary Metabolism/genetics ; Siderophores/genetics ; *Fish Diseases/microbiology ; Gene Transfer, Horizontal ; Peptide Synthases/genetics ; },
abstract = {Fish-pathogenic bacteria threaten global aquaculture, yet their biosynthetic capacity for secondary metabolites remains unexplored at the genomic scale. We present the first cross-genus atlas of biosynthetic gene clusters (BGCs) in prokaryotic fish pathogens, analyzing 1,855 genomes across 12 families and 14 genera. Using antiSMASH and BiG-SCAPE, we identified 13,626 BGCs encoding NRPS, PKS, RiPPs, terpenes, and siderophores, organized into 2,842 gene cluster families. Strikingly, 1,724 families (61%) lack close MIBiG reference homologs (designated here as MIBiG-distant clusters), representing potentially underexplored enzymatic diversity. Genus-level analyses revealed pronounced specialization: Pseudomonas, Mycobacterium, and Nocardia harbor NRPS/PKS-rich repertoires (> 5 BGCs/genome), while Streptococcus and Enterococcus exhibit streamlined RiPP-dominated profiles. Network analysis identified cross-taxon BGC sharing patterns consistent with horizontal gene transfer among aquatic lineages and massive within-genus expansions, with Flavobacterium RiPP families averaging 69 members. Genome-wide correlations linked GC content to BGC density (r = 0.41, p < 0.001), with genus-specific relationships ranging from r = 0.77 (Chryseobacterium) to r = -0.84 (Lactococcus), revealing compositional constraints on metabolic evolution. BGC distribution patterns reflected ecological lifestyle and suggested potential roles in iron acquisition, interspecies competition, and host colonization. This molecular inventory establishes fish-pathogenic bacteria as a strategic frontier for natural product discovery, providing a phylogenetically resolved roadmap for isolating antimicrobials, siderophores, and biofilm modulators with applications in sustainable aquaculture disease management.},
}

*Multigene Family
Animals
*Fishes/microbiology
*Genome, Bacterial
*Bacteria/genetics/metabolism/classification
Phylogeny
*Biosynthetic Pathways/genetics
Secondary Metabolism/genetics
Siderophores/genetics
*Fish Diseases/microbiology
Gene Transfer, Horizontal
Peptide Synthases/genetics

@article {pmid42026459,
year = {2026},
author = {Holman, DE and Klein, A and Keyster, M},
title = {Whole-genome characterization and analysis of Pantoea agglomerans R6: a genomic insight into its pathogenicity and resistance as a potential opportunistic plant pathogen.},
journal = {BMC genomics},
volume = {27},
number = {1},
pages = {},
pmid = {42026459},
issn = {1471-2164},
abstract = {UNLABELLED: Pantoea agglomerans is a Gram-negative bacterium increasingly recognised as an opportunistic pathogen, yet the molecular basis underpinning its host-interaction capacity remains poorly understood. Here, we report the whole-genome sequencing and integrative characterisation of P. agglomerans strain R6, isolated from Lactuca serriola. The 4.7 Mb draft genome (GC content 55.6%) encodes 4,349 genes, including secretion system components, siderophore clusters, adhesins, and multidrug efflux pumps. Comparative genomic analysis against previously characterised Pantoea strains revealed an open pan-genome shaped by horizontal gene transfer, with multiple genomic islands harbouring putative virulence- and resistance-associated loci. Notably, homologues of type VI secretion system components, iron acquisition systems, and stress response pathways suggest adaptive potential during host colonisation. Complementary phenotypic assays supported these genomic predictions, demonstrating swarming motility, biofilm formation, extracellular polysaccharide production, and enzymatic activities associated with host interaction in related strains. While R6 displayed susceptibility to β-lactams, its genomic repertoire indicates potential for adaptive resilience under selective pressure. This integrative genomic and phenotypic characterisation identifies candidate molecular features associated with opportunistic behaviour and highlights the genomic potential of R6, rather than experimentally validated causal determinants of pathogenicity.

SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12864-026-12875-9.},
}

@article {pmid42262838,
year = {2026},
author = {Deventer, AT and Sutherland, A and Biernacka, D and Johnston, PR and Stevens, CE and Kaczorowska, AK and Boraston, AB and Hobbs, JK},
title = {Clinical Rel mutations that increase basal (p)ppGpp promote conjugal transfer of staphylococcal resistance plasmids.},
journal = {Microbiology (Reading, England)},
volume = {172},
number = {6},
pages = {},
pmid = {42262838},
issn = {1465-2080},
mesh = {*Staphylococcus aureus/genetics/drug effects/metabolism ; *Plasmids/genetics/metabolism ; *Conjugation, Genetic ; Mutation ; *Guanosine Tetraphosphate/metabolism ; *Guanosine Pentaphosphate/metabolism ; *Drug Resistance, Bacterial/genetics ; *Bacterial Proteins/genetics/metabolism ; Anti-Bacterial Agents/pharmacology ; Staphylococcal Infections/microbiology ; Gene Expression Regulation, Bacterial ; Humans ; Gene Transfer, Horizontal ; },
abstract = {Conjugative transfer of plasmids represents a major route through which antibiotic resistance genes are spread. In the case of the prevalent and deadly pathogen Staphylococcus aureus, more than 90% of clinical isolates carry at least one plasmid. While plasmid-encoded mechanisms [e.g. plasmid copy number (PCN)] can influence conjugation frequency, host factors and environmental stimuli can also affect transmission. In particular, stress responses like the stringent response have been associated with increased movement of mobile genetic elements. We have previously shown that clinical mutations in the stringent response controller, Rel, lead to elevated levels of the alarmones guanosine tetra- and pentaphosphate [(p)ppGpp] and antibiotic tolerance in S. aureus. Here, we report that elevated (p)ppGpp in these strains promotes the conjugal transfer of diverse staphylococcal resistance plasmids. We observed that clinical Rel mutations promote donation, but not receipt, of plasmids from the three families of staphylococcal plasmid and a mobilizable plasmid. This increased conjugation frequency could also be induced by chemical induction of the stringent response by mupirocin. Intriguingly, detailed experimental analysis revealed that the effect of elevated (p)ppGpp on plasmid donation was not due to CodY derepression, SOS response induction or increased PCN. Furthermore, comparative transcriptomics of wild-type and mutant donor did not highlight any putative plasmid- or host-derived mechanisms to explain this observation. Further investigations are required to explore the mechanistic link between (p)ppGpp and conjugation, given the pervasive transcriptional and post-translational effects of (p)ppGpp. Overall, the association between Rel mutation and increased plasmid donation is alarming, especially as Rel mutations are being increasingly identified among clinical isolates.},
}

*Staphylococcus aureus/genetics/drug effects/metabolism
*Plasmids/genetics/metabolism
*Conjugation, Genetic
Mutation
*Guanosine Tetraphosphate/metabolism
*Guanosine Pentaphosphate/metabolism
*Drug Resistance, Bacterial/genetics
*Bacterial Proteins/genetics/metabolism
Anti-Bacterial Agents/pharmacology
Staphylococcal Infections/microbiology
Gene Expression Regulation, Bacterial
Humans
Gene Transfer, Horizontal

@article {pmid42275600,
year = {2026},
author = {Matrougui, I and Oukkal, S and Musset, K and Orieux, E and Drezen, JM and Charlat, S and Gilbert, C},
title = {Horizontal transfers of polydnavirus segments extend the known range of parasitoid attacks to stick insects and orthopterans.},
journal = {Molecular biology and evolution},
volume = {},
number = {},
pages = {},
doi = {10.1093/molbev/msag145},
pmid = {42275600},
issn = {1537-1719},
abstract = {Horizontal gene transfer occurs beyond anecdotal frequencies in metazoans. Among insects, some parasitoid wasps even carry gene delivery agents called polydnaviruses (PDVs). These domesticated viral elements mediate the integration of wasp genes into the genome of parasitized hosts, thereby protecting developing larvae from immune defenses. The frequency of PDV-mediated transfers is sufficiently high that it could be exploited to better characterize the range of organisms attacked by parasitoid wasps. Here, we apply this rationale by screening for the specific molecular footprints of these transfers in 6,814 protostome genomes. We found a total of 6,556 PDV-mediated integrations, all of which were in insects. The distribution of these integrations is highly consistent with the known host range of PDV-encoding parasitoid wasps. Most were found in lepidopterans (6,260 integrations in 303 species) - the main hosts of PDV-encoding wasps - and a few were retrieved in sawflies (139 integrations in 14 species) and leaf beetles (4 integrations in 2 species), also known to be parasitized by some of these wasps. Remarkably, we found a total of 232 integrations in 3 species of stick insects and one integration in an orthopteran, two insect lineages that have never been reported to be attacked by PDV-encoding wasps. We show that these integrations are mostly recent and that stick insects and sawflies were attacked recurrently, by multiple wasp lineages. Overall, our study warrants accounting for stick insects and orthopterans as possible new targets of parasitoid attacks, both in community ecology and in assessments of biological control strategies.},
}

@article {pmid42275669,
year = {2026},
author = {Sun, EG and Ventura, A},
title = {Seeing is Believing: Intercellular Transfer of DNA between human cells.},
journal = {Cancer research},
volume = {},
number = {},
pages = {},
doi = {10.1158/0008-5472.CAN-26-2540},
pmid = {42275669},
issn = {1538-7445},
abstract = {Genomic insults in the form of DNA damage and mitotic errors can result in mis-localization of nuclear DNA into the cytoplasm in the form of micronuclei or as fragmented chromosomal elements. Recent work from the Ly lab has demonstrated that cytoplasmic DNAs can undergo intercellular transfer via nanotube-like connections. Using a variety of cell lines, the authors demonstrate the transfer of DNA through nanotubes and that various sources of genome instability can promote this phenomenon. Crucially, the transferred DNA can be incorporated into the nucleus of recipient cells and intermix with host chromosomes. Additionally, the transferred DNA molecules are functional and can provide a fitness advantage to recipient cells. These findings uncover a novel horizontal gene transfer mechanism in human cells, which could have profound implications in human disease and biology.},
}

@article {pmid42276346,
year = {2026},
author = {Harith-Fadzilah, N and Iskandar Sahran, MS and Bin Khairil, MF and Ahmad, HF},
title = {In Silico Identification and characterisation of putative biphenyl degradation mechanism in gut-Derived Pediococcus pentosaceus.},
journal = {Environmental research},
volume = {},
number = {},
pages = {125000},
doi = {10.1016/j.envres.2026.125000},
pmid = {42276346},
issn = {1096-0953},
abstract = {Polychlorinated biphenyls (PCBs) persist in the environment and bioaccumulate through the food chain. Probiotic microorganisms offer a potential strategy to reduce PCB uptake in livestock guts. This study aimed to identify and characterise potential biphenyl degradation capabilities in Pediococcus pentosaceus QS-GN03_1, isolated from the gut of the cockroach, Periplaneta americana for application as a PCB-detoxifying probiotic feed additive. Whole-genome sequencing yielded an approximately 1.86 Mbp assembly with 98.3 % BUSCO completeness. Genomic annotation revealed the presence of a putative biphenyl-2,3-diol 1,2-dioxygenase (BphC; PPBPHCIII) homologue. Compositional analysis surrounding this gene identified atypical genomic singatures and nearby IS481/ISNCY insertion sequence which suggests this gene locus was acquired through horizontal gene transfer independent of other bph genes. Promoter analysis affirmed PPBPHCIII possesses promoter elements and adopts a structure highly similar to functional BphC enzymes from the Protein Data Bank (RMSD 1.357 Å against Pseudomonas BphC PDB ID: 1EIR benchmark). Molecular docking and 100 ns averaged molecular dynamics (MD) simulations indicated stable binding of 2,3-dichlorobiphenyl ligand within a conserved active site coordinated by Fe (II), primarily via electrostatic and hydrophobic interactions. However, the free ligand binding energy calculations predicted a weaker binding affinity for PPBPHCIII compared to the functionally verified 1EIR complex which the difference was primarily due to fewer hydrogen bonds formations. While QS-GN03_1 lacks independent PCB mineralisation capabilities, the isolated presence of a highly ameliorated bphC gene suggests and ancient horizontal acquisition of a larger Bph operon, followed by reductive evolution due to lack of selective pressure. The discovery of native IS30-family insertion sequences within its genome offers synthetic biology opportunity for chromosomal integration of a complete Bph operon, allowing the generation of QS-GN03_1 with complete PCB degradation capability.},
}

@article {pmid42276819,
year = {2026},
author = {Zhang, Q and Lin, R and Zhao, Y and Zhan, P and Zhao, X and Zou, W},
title = {Biofilm-mediated antibiotic tolerance in bacterial pathogens: Integrated molecular networks and novel therapeutic avenues.},
journal = {Virulence},
volume = {},
number = {},
pages = {2687214},
doi = {10.1080/21505594.2026.2687214},
pmid = {42276819},
issn = {2150-5608},
abstract = {The stable structure of biofilms and the characteristics of the bacteria within them make biofilms an important barrier for bacteria to resist external stress, and a key factor contributing to the difficulty of eradicating clinical infections. This article reviews the multi-stage formation process of biofilms, the various mechanisms of antibiotic tolerance and resistance (such as physical barriers, metabolic adaptations, horizontal gene transfer, etc.), as well as the integrated regulatory roles of molecular networks like quorum sensing (QS) and cyclic diguanosine monophosphate (c-di-GMP). These multiple protective mechanisms in biofilms compose a closed "structure-function" loop system. In the past few years, the emergence of new anti-biofilm intervention approaches (matrix-degrading enzymes, phage therapy, nanomaterials, gene editing, etc.) revealed the possibility to break the limitations of conventional antibiotics by compromising structural integrity or interfering with signaling pathways, providing new ideas for drug-resistance infection control.},
}

@article {pmid42277643,
year = {2026},
author = {Rahimian, M and Aghazadeh-Soltan-Ahmadi, M},
title = {Evolutionary interplay: virulence, endolysin-like hydrolases, and defense correlations in the Erwinia amylovora pangenome.},
journal = {BMC microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1186/s12866-026-05295-y},
pmid = {42277643},
issn = {1471-2180},
abstract = {Erwinia amylovora, the causative agent of fire blight, poses a significant threat to global pome fruit production. This study presents a comprehensive genomic analysis of 317 E. amylovora strains and 227 Erwinia phages to elucidate virulence evolution, phage-host dynamics, and the genomic signatures of the co-evolutionary arms race. Our analysis suggests that a substantial portion of E. amylovora's virulence factors (VFs) share evolutionary origins with diverse plant, human, and animal pathogens, underscoring widespread horizontal gene transfer. We identified bacterial phage hydrolases‑like proteins that share phylogenetic and domain-level similarities with phage endolysins. These observations are consistent with the possibility that some bacterial hydrolases originated from phage-derived ancestors, although functional repurposing remains to be experimentally validated. Crucially, our analysis identifies systematic, non-random associations between bacterial defense systems (e.g., RM, CRISPR-Cas, TA) and mobile anti-defense genes. Statistical correlations show strong patterns of co-occurrence and mutual exclusivity, which are consistent with an ongoing phage-bacteria arms race. These patterns provide a genomic basis for generating hypotheses about co-evolutionary dynamics. These findings may advance our understanding of E. amylovora pathogenicity and phage interactions, offering foundational insights for developing targeted phage-based biocontrol strategies against this devastating plant pathogen. Experimental validation of the predicted virulence factors and defense correlations is warranted to confirm their biological roles.},
}

@article {pmid42278533,
year = {2026},
author = {Ramadan, YN and Bukhari, SQ and Alatawi, Z and Oriquat, G and Ellah, NHA and Mohamedosman, EHA and Ahmed, R and Hetta, HF},
title = {Evolutionary Genomics of Human Gut Bacteria: Ecological Plasticity Across the Mutualism-Pathogenicity Spectrum.},
journal = {International journal of molecular sciences},
volume = {27},
number = {11},
pages = {},
doi = {10.3390/ijms27115009},
pmid = {42278533},
issn = {1422-0067},
abstract = {The human gut microbiome comprises a diverse community of bacteria whose interactions with the host range from beneficial mutualism to opportunistic pathogenicity. These interactions are shaped by genomic plasticity and ecological pressures that influence whether microbes support host health, remain conditionally harmless, or contribute to disease. Understanding the mechanisms underlying these shifts is essential for clarifying the balance between cooperation and pathogenicity within the gut ecosystem. This review explores the genomic and evolutionary mechanisms that shape microbial adaptation across the mutualism-pathogenicity spectrum in the human gut. Key processes, including horizontal gene transfer (HGT), host-mediated selection, and niche specialization, enable microbes to acquire, regulate, or retain traits that influence colonization, metabolic function, and virulence. These adaptive mechanisms allow gut bacteria to respond dynamically to ecological pressures such as inflammation, antibiotic exposure, and dietary change, resulting in context-dependent microbial behaviors. The review also considers how concepts from insect endosymbiosis may provide insight into gut microbial adaptation. While both systems exhibit host specialization, major differences in transmission mode, ecological flexibility, and genome evolution limit direct comparisons. Rather than following a fixed progression toward parasitism, gut microbes exhibit flexible adaptive strategies shaped by host and environmental conditions. By integrating ecological and evolutionary perspectives, this review presents a balanced framework for understanding how genomic adaptation influences microbial behavior in the gut. This perspective improves our understanding of dysbiosis and microbial pathogenesis and may support the development of microbiome-informed therapeutic strategies for maintaining host health.},
}

@article {pmid41991117,
year = {2026},
author = {Kreins-Irle, M and Berger, M and Solti-Hodován, Á and Mukherjee, K and Singh, R and Greune, L and Bányai, K and López, RF and Dersch, P and Schneider, G and Dobrindt, U},
title = {Investigating the role of novel alphatectiviruses in reducing carriage and transfer of antimicrobial resistance plasmids.},
journal = {International journal of antimicrobial agents},
volume = {67},
number = {7},
pages = {107806},
doi = {10.1016/j.ijantimicag.2026.107806},
pmid = {41991117},
issn = {1872-7913},
mesh = {*Plasmids/genetics ; Animals ; *Escherichia coli/virology/genetics ; *Drug Resistance, Bacterial/genetics ; Host Specificity ; *Gene Transfer, Horizontal ; Conjugation, Genetic ; *Bacteriophages/physiology ; Anti-Bacterial Agents/pharmacology ; },
abstract = {OBJECTIVE: To identify suitable phage isolates and the characterization of factors that define their host range and interactions with bacteria, which are of major importance for optimizing their use in reducing antimicrobial resistance (AMR).

METHODS: We characterized two novel conjugation apparatus-specific alphatectiviruses that target plasmids of the incompatibility groups IncW, N, and P. We show that ɸ4187/61 and ɸ4187/77 specifically target plasmid-harbouring bacteria in mixed bacterial populations, thereby reducing overall plasmid carriage and transfer.

RESULTS: Occurring phage resistance was associated with plasmid loss or greatly reduced plasmid transfer efficiency, further supporting the desired reducing effect of phage treatment on AMR plasmid dissemination. The host range of the two alphatectiviruses was not only determined by the type of the plasmid-encoded conjugation apparatus but also by other properties related to the conjugative plasmid, bacterial host, or phage. Treatment of Galleria mellonella larvae force-fed with Escherichia coli MG1655 carrying plasmid RP4 with ɸ4187/77 significantly reduced the RP4 transfer frequency and total number of RP4-harbouring bacteria in the G. mellonella gut.

CONCLUSIONS: Alphatectiviruses such as ɸ4187/61 and ɸ4187/77 are promising candidates for approaches to combat AMR by phage-dependent reduction of plasmid carriage and transfer.},
}

*Plasmids/genetics
Animals
*Escherichia coli/virology/genetics
*Drug Resistance, Bacterial/genetics
Host Specificity
*Gene Transfer, Horizontal
Conjugation, Genetic
*Bacteriophages/physiology
Anti-Bacterial Agents/pharmacology

@article {pmid42263430,
year = {2026},
author = {Fatima, H and Viejo-Borbolla, A and Krey, T},
title = {Architecture and evolution of viral complement evasion.},
journal = {Current opinion in virology},
volume = {76},
number = {},
pages = {101563},
doi = {10.1016/j.coviro.2026.101563},
pmid = {42263430},
issn = {1879-6265},
abstract = {The complement system constitutes a powerful antiviral defense, centered on C3b-mediated amplification that drives opsonization, inflammation, and membrane attack complex formation. To persist in the eukaryotic host, viruses must neutralize this amplification step, and strikingly diverse evolutionary lineages have converged on inhibiting C3b-mediated amplification. In this review, we compare host and viral regulators of complement activation (RCAs) to reveal the structural and mechanistic principles underlying C3b control. Human RCAs achieve complement regulation through modular assemblies of complement control protein domains whose multivalency, linker-encoded geometry, and domain-specific dynamics enable efficient decay acceleration and factor I cofactor activity. Viruses have independently replicated these principles through distinct evolutionary routes. Poxviruses and gammaherpesviruses acquired host-derived RCA genes via horizontal gene transfer, followed by lineage-specific refinement on extensively different time scales. In contrast, alphaherpesviruses evolved structurally unrelated complement inhibitors, exemplified by glycoprotein C, which suppresses C3b via a binding interface distinct from that used by RCAs. Despite profound structural divergence, most viral strategies converge on inhibition of the C3b amplification loop. This convergence highlights C3b suppression as an evolutionary bottleneck imposed by complement and reveals a fundamental asymmetry between structural innovation and functional constraint. Understanding how viruses repeatedly solve this invariant problem identifies complement regulation as a durable vulnerability and suggests therapeutic strategies resilient to viral diversity and mutation-driven escape.},
}