Co-occurrence and co-expression of antibiotic, biocide, and metal resistance genes with mobile genetic elements in microbial communities subjected to long-term antibiotic pressure: Novel insights from metagenomics and metatranscriptomics. - Related Documents




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688001.0000Co-occurrence and co-expression of antibiotic, biocide, and metal resistance genes with mobile genetic elements in microbial communities subjected to long-term antibiotic pressure: Novel insights from metagenomics and metatranscriptomics. The burgeoning of antibiotic resistance has emerged as a pressing global challenge. To gain a deeper understanding of the interactions between antibiotic resistance genes (ARGs), biocide and metal resistance genes (BRGs&MRGs), and mobile genetic elements (MGEs), this study utilized metagenomics and metatranscriptomics to investigate their co-occurrence and co-expression in two consortia subjected to long-term exposure to chloramphenicol and lincomycin. Long-term exposure to these antibiotics resulted in significant disparities in resistance profiles: Consortium(CAP) harbored 130 ARGs and 150 BRGs&MRGs, while Consortium(LIN) contained 57 ARGs and 32 BRGs&MRGs. Horizontal gene transfer (HGT) events were predicted at 125 and 300 instances in Consortium(CAP) and Consortium(LIN), respectively, facilitating the emergence of multidrug-resistant bacteria, such as Caballeronia (10 ARGs, 2 BRGs&MRGs), Cupriavidus (2 ARGs, 10 BRGs&MRGs), and Bacillus (14 ARGs, 21 BRGs&MRGs). Chloramphenicol exposure significantly enriched genes linked to phenicol resistance (floR, capO) and co-expressed ARGs and BRGs&MRGs, while lincomycin exerted narrower effects on resistance genes. Additionally, both antibiotics modulated the expression of degradation genes and virulence factors, highlighting their role in altering bacterial substrate utilization and pathogenic traits. This study provides quantitative insights into the impact of antibiotics on microbial resistance profiles and functions at both DNA and RNA levels, highlighting the importance of reducing antibiotic pollution and limiting the spread of resistance genes in the environment.202539965334
688210.9999Deciphering the mobility and bacterial hosts of antibiotic resistance genes under antibiotic selection pressure by metagenomic assembly and binning approaches. The presence of antibiotics can exert significant selection pressure on the emergence and spread of antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB). However, co-selection effects for ARGs, the mobility of ARGs and the identification of ARG hosts under high antibiotic selection pressures are poorly understood. Here, metagenomic assembly and binning approaches were used to comprehensively decipher the prevalence of ARGs and their potential mobility and hosts in activated sludge reactors treating antibiotic production wastewater. We found the abundance of different ARG types in antibiotic treatments varied greatly and certain antibiotic pressure promoted the co-selection for the non-corresponding types of ARGs. Antibiotic selection pressures significantly increased the abundance and proportions of ARGs mediated by plasmids (57.9%), which were more prevalent than those encoded in chromosomes (19.2%). The results indicated that plasmids and chromosomes had a tendency to carry different types of ARGs. Moreover, higher co-occurrence frequency of ARGs and MGEs revealed that antibiotics enhanced the mobility potential of ARGs mediated by both plasmids and integrative and conjugative elements. Among the 689 metagenome-assembled genomes (MAGs) with high estimated quality, 119 MAGs assigning to nine bacterial phyla were identified as the ARG hosts and 33 MAGs exhibited possible multi-resistance to antibiotics. Some ARG types tended to be carried by certain bacteria (e.g. bacitracin resistance genes carried by the family Burkholderiaceae) and thus showed a pronounced host-specific pattern. This study enhances the understanding of the mobility and hosts of ARGs and provides important insights into the risk assessment and management of antibiotic resistance.202032871290
689120.9998Feedstock-dependent antibiotic resistance gene patterns and expression profiles in industrial scale biogas plants revealed by meta-omics technology. This study investigated antimicrobial resistance in the anaerobic digesters of two industrial-scale biogas plants processing agricultural biomass and municipal wastewater sludge. A combination of deep sequencing and genome-centric workflow was implemented for metagenomic and metatranscriptomics data analysis to comprehensively examine potential antimicrobial resistance in microbial communities. Anaerobic microbes were found to harbour numerous antibiotic resistance genes (ARGs), with 58.85% of the metagenome-assembled genomes (MAGs) harbouring antibiotic resistance. A moderately positive correlation was observed between the abundance and expression of ARGs. ARGs were located primarily on bacterial chromosomes. A higher expression of resistance genes was observed on plasmids than on chromosomes. Risk index assessment suggests that most ARGs identified posed a significant risk to human health. However, potentially pathogenic bacteria showed lower ARG expression than non-pathogenic ones, indicating that anaerobic treatment is effective against pathogenic microbes. Resistomes at the gene category level were associated with various antibiotic resistance categories, including multidrug resistance, beta-lactams, glycopeptides, peptides, and macrolide-lincosamide-streptogramin (MLS). Differential expression analysis revealed specific genes associated with potential pathogenicity, emphasizing the importance of active gene expression in assessing the risks associated with ARGs.202539461216
688130.9998Spatiotemporal profiles and underlying mechanisms of the antibiotic resistome in two water-diversion lakes. Human-induced interventions have altered the local characteristics of the lake ecosystems through changes in hydraulic exchange, which in turn impacts the ecological processes of antibiotic resistance genes (ARGs) in the lakes. However, the current understanding of the spatiotemporal patterns and driving factors of ARGs in water-diversion lakes is still seriously insufficient. In the present study, we investigated antibiotic resistome in the main regulation and storage hubs, namely Nansi Lake and Dongping Lake, of the eastern part of the South-to-North Water Diversion project in Shandong Province (China) using a metagenomic-based approach. A total of 653 ARG subtypes belonging to 25 ARG types were detected with a total abundance of 0.125-0.390 copies/cell, with the dominance of bacitracin, multidrug, and macrolide-lincosamide streptogramin resistance genes. The ARG compositions were sensitive to seasonal variation and also interfered by artificial regulation structures along the way. Human pathogenic bacteria such as Acinetobacter calcoaceticus, Acinetobacter lwoffii, Klebsiella pneumoniae, along with the multidrug resistance genes they carried, were the focus of risk control in the two studied lakes, especially in summer. Plasmids were the key mobile genetic elements (MGEs) driving the horizontal gene transfer of ARGs, especially multidrug and sulfonamide resistance genes. The null model revealed that stochastic process was the main driver of ecological drift for ARGs in the lakes. The partial least squares structural equation model further determined that seasonal changes of pH and temperature drove a shift in the bacterial community, which in turn shaped the profile of ARGs by altering the composition of MGEs, antibacterial biocide- and metal-resistance genes (BMGs), and virulence factor genes (VFGs). Our results highlighted the importance of seasonal factors in determining the water transfer period. These findings can aid in a deeper understanding of the spatiotemporal variations of ARGs in lakes and their driving factors, offering a scientific basis for antibiotic resistance management.202439322056
689540.9998Effects of heavy metals pollution on the co-selection of metal and antibiotic resistance in urban rivers in UK and India. Heavy metal pollution and the potential for co-selection of resistance to antibiotics in the environment is growing concern. However, clear associations between heavy metals and antibiotic resistance in river systems have not been developed. Here we investigated relationships between total and bioavailable heavy metals concentrations; metal resistance gene (MRG) and antibiotic resistance gene (ARG) abundances; mobile genetic elements; and the composition of local bacterial communities in low and high metal polluted rivers in UK and India. The results indicated that MRGs conferring resistance to cobalt (Co) and nickel (Ni) (rcnA), and Co, zinc (Zn), and cadmium (Cd) (czcA), and ARGs conferring resistance to carbapenem and erythromycin were the dominating resistant genes across the samples. The relative MRGs, ARGs, and integrons abundances tended to increase at high metal polluted environments, suggesting high metals concentrations have a strong potential to promote metal and antibiotic resistance by horizontal gene transmission and affecting bacterial communities, leading to the development of multi-metal and multi-antibiotic resistance. Network analysis demonstrated the positive and significant relationships between MRGs and ARGs as well as the potential for integrons playing a role in the co-transmission of MRGs and ARGs (r > 0.80, p < 0.05). Additionally, the major host bacteria of various MRGs and ARGs that could be accountable for greater MRGs and ARGs levels at high metal polluted environments were also identified by network analysis. Spearman's rank-order correlations and RDA analysis further confirm relationships between total and bioavailable heavy metals concentrations and the relative MRG, ARG, and integron abundances, as well as the composition of related bacterial communities (r > 0.80 (or < -0.80), p < 0.05). These findings are critical for assessing the possible human health concerns associated with metal-driven antibiotic resistance and highlight the need of considering metal pollution for developing appropriate measures to control ARG transmission.202235491000
682950.9998Metagenomic insights into the characteristics and co-migration of antibiotic resistome and metal(loid) resistance genes in urban landfill soil and groundwater. The heavy metals and antibiotic resistance genes (ARGs) in landfills showed a significant correlation; however, the relationship between metal(loid) resistance genes (MRGs) and ARGs in contaminated environments, as well as whether they co-migrate with human pathogenic bacteria (HPB), remains unclear. This study is the first to report the characteristics and co-migration of ARGs and MRGs in the soil and groundwater of aged urban landfill sites. Our findings indicated that quinolone, efflux, and macrolide-lincosamide-streptogramin represented the most abundant ARGs identified. Notably, ARG abundance was higher in groundwater compared to soil, with subtype diversity reflecting a similar trend; however, microbial diversity in soil was greater. Metagenome-assembled genomes data indicated a higher risk of antibiotic-resistant HPB in groundwater. It is imperative to focus on HPB that co-carry ARGs and MRGs alongside mobile genetic elements (MGEs), such as Ralstonia pickettii and Pseudomonas stutzeri. Genes conferring resistance to copper and mercury, as well as MGEs such as qacEdelta and intI1, played a critical role in promoting horizontal gene transfer of antibiotic resistance. MRG may promote ARG migration by affecting the permeability of the cell membrane. Procrustes analysis revealed a strong similarity (87 %) between heavy metals and MRG structures. Variance partitioning analyses demonstrated that both heavy metals and biological factors jointly governed landfill ARGs (96.2 %), exerting a more substantial influence in groundwater than in soil. This study serves as a reference for managing landfill, while emphasizing the importance of addressing the co-migration of MRGs and ARGs in pathogens when controlling the spread of risks.202540614847
687960.9998Airborne antibiotic and metal resistance genes - A neglected potential risk at e-waste recycling facilities. Heavy metal-rich environments can promote the selection of metal-resistance genes (MRGs) in bacteria, often leading to the simultaneous selection of antibiotic-resistance genes (ARGs) through a process known as co-selection. To comprehensively evaluate the biological pollutants at electronic-waste (e-waste) recycling facilities, air, soil, and river samples were collected at four distinct Swiss e-waste recycling facilities and analyzed for ARGs, MRGs, mobile genetic elements (MGEs), endotoxins, and bacterial species, with correlations drawn to heavy metal occurrence. To our knowledge, the present work marks the first attempt to quantify these bio-pollutants in the air of e-waste recycling facilities, that might pose a significant health risk to workers. Although ARG and MRG's profiles varied among the different sample types, intl1 consistently exhibited high relative abundance rates, identifying it as the predominant MGE across all sample types and facilities. These findings underscore its pivol role in driving diverse bacterial adaptations to extreme heavy metal exposure by selection and dissemination of ARGs and MRGs. All air samples exhibited consistent profiles of ARGs and MRGs, with blaTEM emerging as the predominant ARG, alongside pbrT and nccA as the most prevalent MRGs. However, one facility, engaged in batteries recycling and characterized by exceptionally high concentrations of heavy metals, showcased a more diverse resistance gene profile, suggesting that bacteria in this environment required more complex resistance mechanisms to cope with extreme metal exposure. Furthermore, this study unveiled a strong association between gram-negative bacteria and ARGs and less with MRGs. Overall, this research emphasizes the critical importance of studying biological pollutants in the air of e-waste recycling facilities to inform robust safety measures and mitigate the risk of resistance gene dissemination among workers. These findings establish a solid foundation for further investigations into the complex interplay among heavy metal exposure, bacterial adaptation, and resistance patterns in such distinctive ecosystems.202438365028
703170.9998Free-living lifestyle preferences drive the antibiotic resistance promotion during drinking water chlorination. The risk associated with antibiotic resistance genes (ARGs) in size-fractionated bacterial community during drinking water chlorination remains unclear, and is of paramount importance for risk mitigation through process selection and optimization. This study employed metagenomic approaches to reveal the alterations of ARGs, their potential functions and hosts within the free-living and particle-associated fractions. The total relative abundance of ARGs, mobile genetic elements (MGEs), and virulence factor genes (VFGs) significantly increased in the free-living fraction after chlorination. The contribution of the free-living fraction to the ARG relative abundance rose from 16.40 ± 1.31 % to 93.62 ± 0.47 % after chlorination. Multidrug resistance genes (e.g. mexF and mexW) were major contributors, and their co-occurrence with MGEs in the free-living fraction was enhanced after chlorination. Considering multiple perspectives, including presence, mobility, and pathogenicity, chlorination led to a significant risk of the antibiotic resistome in the free-living fraction. Moreover, potential functions of ARGs, such as cell wall/membrane/envelope biogenesis, defense mechanisms, and transcription in the free-living fraction, were intensified following chlorination. Potential pathogens, including Pseudomonas aeruginosa, Pseudomonas alcaligenes, and Acinetobacter junii, were identified as the predominant hosts of multidrug resistance genes, with their increased abundances primarily contributing to the rise of the corresponding ARGs. Overall, alterations of hosts as well as enhancing mobility and biological functions could collectively aid the proliferation and spread of ARGs in the free-living fraction after chlorination. This study provides novel insights into antibiotic resistance evolution in size-fractionated bacteria community and offers a management strategy for microbiological safety in drinking water.202438043346
746880.9998Enrofloxacin-induced transfer of multiple-antibiotic resistance genes and emergence of novel resistant bacteria in red swamp crayfish guts and pond sediments. Antibiotic resistance genes (ARGs) can be transferred from environmental microbes to human pathogens, thus leading to bacterial infection treatment failures. The aquaculture polluted by over-used antibiotics is considered as a notorious reservoir of ARGs. However, the origin, diachronic changes, and mobility of ARGs under antibiotic exposure in aquaculture systems remain elusive. Our findings showed that enrofloxacin application also increased the relative abundance of various ARGs in addition to quinolone-resistance genes and induced ARG dissemination in crayfish gut and sediment bacteria. Further investigation indicated that the transposase-mediated recombination was the major driver of horizontal gene transfer (HGT) of ARGs under antibiotic stress. Notably, enrofloxacin application also induced the generation of some metagenome-assembled genomes (MAGs) carrying multiple ARGs, which were identified as novel species. Additionally, Enterobacteriaceae constituted a mobile ARG pool in aquaculture. Therefore, aquaculture provides potential wide environmental pathways for generation and spread of antibiotic resistance. Our findings of ARG temporal variations and dissemination pattern in aquaculture with artificial use of antibiotics are critical to the management of antibiotic resistance, which is of great ecosystem and health implications.202336356515
688390.9998Metagenomic insights into the profile of antibiotic resistomes in sediments of aquaculture wastewater treatment system. To meet the rapidly growing global demand for aquaculture products, large amounts of antibiotics were used in aquaculture, which might accelerate the evolution of antibiotic-resistant bacteria (ARB) and the propagation of antibiotic genes (ARGs). In our research, we revealed the ARGs profiles, their co-occurrence with mobile genetic elements (MGEs), and potential hosts in sediments of a crab pond wastewater purification system based on metagenomic analysis. The residual antibiotic seems to increase the propagation of ARGs in the crab pond, but there was no clear relationship between a given antibiotic type and the corresponding resistance genes. The effect of aquaculture on sediment was not as profound as that of other anthropogentic activities, but increased the relative abundance of sulfonamide resistance gene. A higher abundance of MGEs, especially plasmid, increased the potential ARGs dissemination risk in crab and purification ponds. Multidrug and sulfonamide resistance genes had greater potential to transfer because they were more frequently carried by MGEs. The horizontal gene transfer was likely to occur among a variety of microorganisms, and various ARGs hosts including Pseudomonas, Acinetobacter, Escherichia, and Klebsiella were identified. Bacterial community influenced the composition of ARG hosts, and Proteobacteria was the predominant hosts. Overall, our study provides novel insights into the environmental risk of ARGs in sediments of aquaculture wastewater treatment system.202234963542
6894100.9998Profiles of antibiotic- and heavy metal-related resistance genes in animal manure revealed using a metagenomic analysis. Farmed animals produce excrement containing excessive amounts of toxic heavy metals as a result of consuming compound feed as well as receiving medical treatments, and the presence of these heavy metals may aggravate the risk of spreading drug-resistance genes through co-selection during manure treatment and application processes. However, research on the association between heavy metals and antimicrobial resistance is still lacking. In this study, metagenomic sequencing was used to explore the effects of the co-selection of environmentally toxic heavy metals on the resistome in manure. A relevance network analysis showed that metal-resistance genes (MRGs), especially for copper (Cu) and zinc (Zn), were positively correlated with multiple types of antibiotic-resistance genes (ARGs) and formed a complex network. Most bacteria that co-occurred with both MRGs and ARGs simultaneously are members of Proteobacteria and accounted for 54.7% of the total microbial species in the relevance network. The remaining bacteria belonged to Firmicutes, Bacteroidetes and Actinobacteria. Among the four phyla, Cu- and Zn-resistance genes had more complex correlations with ARGs than other MRG types, reflecting the occurrence of ARG co-selection under the selective pressure of high Cu and Zn levels. In addition, approximately 64.8%, 59.1% and 68.4% of MRGs that correlated with the presence of plasmids, viruses and prophages, respectively, are Cu- or Zn-resistant, and they co-occurred with various ARGs, indicating that mobile genetic elements participate in mediating ARG co-selection in response to Cu and Zn pressure. The results indicated that the use of heavy-metal additives in feed induces the increases of drug resistance genes in manure through co-selection, aggravating the risk of antimicrobial resistance diffusion from animal farm to manure land applications.202235617901
6892110.9998Metagenomic deciphers the mobility and bacterial hosts of antibiotic resistance genes under antibiotics and heavy metals co-selection pressures in constructed wetlands. Both antibiotics and heavy metals exert significant selection pressures on antibiotic-resistance genes (ARGs). This study aimed to investigate the co-selection effects of doxycycline (DC) and cadmium (Cd) on ARGs in constructed wetlands (CWs). The results demonstrated that under antibiotic and heavy metal co-selection pressures, single high concentration DC/Cd or double high, relative abundances of metagenomics assembled genomes all reached 55.1%; meanwhile, the average ratio of ARG-containing contigs located on chromosomes was 61.8% (ranging from 50.4% to 70.6%) suggesting a more stable inheritance of ARGs. Antibiotic and heavy metal co-selection in single high concentration DC/Cd or double high groups stimulate the enrichment of ARG host bacteria, which exhibited complex multiple-resistant patterns accompanied by a host-specific pattern. Additionally, the potential transfer abilities of ARGs mediated by plasmids and integrative and conjugative elements (ICEs) were enhanced under single high-concentration DC/Cd or double high stresses. Together, antibiotic and heavy metal co-selection pressures increased occurrence frequencies of ARGs, MGEs, and their combinations and altered structural communities of ARG host bacteria, increasing the risk of the spread of ARGs. This study was helpful in understanding the dissemination of ARGs and simultaneously preventing the spread of heavy metal-resistant bacteria and ARGs under antibiotic and heavy metal co-selection in small- and micro-wetlands.202539848523
7467120.9998Co-occurrence of antibiotic and metal resistance genes revealed in complete genome collection. The high frequency of antibiotic resistance is a global public health concern. More seriously, widespread metal pressure in the environment may facilitate the proliferation of antibiotic resistance via coselection of antibiotic resistance genes (ARGs) and metal resistance genes (MRGs). Given the lack of comprehensive understanding of the ARG and MRG coselection, in this study both abundance relationship and genetic linkage between ARGs and MRGs were rigorously investigated by performing a genomic analysis of a large complete genome collection. Many more ARGs were enriched in human-associated bacteria compared with those subjected to less anthropogenic interference. The signatures of ARG and MRG co-occurrence were much more frequent and the distance linkages between ARGs and MRGs were much more intimate in human pathogens than those less human-associated bacteria. Moreover, the co-occurrence structures in the habitat divisions were significantly different, which could be attributed to their distinct gene transfer potentials. More exogenous ARGs and MRGs on the genomes of human pathogens indicated the importance of recent resistance acquisition in resistome development of human commensal flora. Overall, the study emphasizes the potential risk associated with ARG and MRG coselection of both environmental and medical relevance.201727959344
3177130.9998Metagenomic investigation of antibiotic resistance genes and resistant bacteria contamination in pharmaceutical plant sites in China. Pharmaceutical plant sites play a significant role in the dissemination of antibiotic resistance genes (ARGs) into the environment. It is imperative to comprehensively monitor of ARGs across various environmental media at these sites. This study focused on three pharmaceutical plants, two located in North China and one in South China. Through metagenomic approaches, we examined the composition, mobility potential, and bacterial hosts of ARGs in diverse media such as process water, groundwater, topsoil, soil cores, and pharmaceutical fermentation residues across diverse environmental matrices, including topsoil, soil cores, process water, groundwater, and pharmaceutical fermentation residues. We identified a wide array of ARGs, comprising 21 types and 740 subtypes, with process water exhibiting the highest abundance and diversity. Treatment processes varied in their efficacy in eliminating ARGs, and the clinically relevant ARGs should also be considered when evaluating wastewater treatment plant efficiency. Geographical distinctions in groundwater ARG distribution between northern and southern regions were observed. Soil samples from the three sites showed minimal impact from pharmaceutical activity, with vancomycin-resistance genes being the most prevalent. High levels of ARGs in pharmaceutical fermentation residues underscore the necessity for improved waste management practices. Metagenomic assembly revealed that plasmid-mediated ARGs were more abundant than chromosome-mediated ARGs. Metagenome-assembled genomes (MAGs) analysis identified 166 MAGs, with 62 harboring multiple ARGs. Certain bacteria tended to carry specific types of ARGs, revealing distinct host-resistance associations. This study enhances our understanding of ARG dissemination across different environmental media within pharmaceutical plants and underscores the importance of implementing strict regulations for effluent and residue discharge to control ARG spread.202438960118
3174140.9998Spatio-temporal variation of the microbiome and resistome repertoire along an anthropogenically dynamic segment of the Ganges River, India. Aquatic ecosystems are regarded as a hub of antibiotic and metal resistance genes. River Ganges is a unique riverine system in India with socio-cultural and economic significance. However, it remains underexplored for its microbiome and associated resistomes along its anthropogenically impacted course. The present study utilized a nanopore sequencing approach to depict the microbial community structure in the sediments of the river Ganges harboring antibiotic and metal resistance genes (A/MRGs) in lower stretches known for anthropogenic impact. Comprehensive microbiome analyses revealed resistance genes against 23 different types of metals and 28 classes of antibiotics. The most dominant ARG category was multidrug resistance, while the most prevalent MRGs conferred resistance against copper and zinc. Seasonal differences dismally affected the microbiota of the Ganges. However, resistance genes for fosmidomycin and tetracycline varied with season ANOVA, p < 0.05. Interestingly, 333 and 334 ARG subtypes were observed at all the locations in pre-monsoon and post-monsoon, respectively. The taxa associated with the dominant ARGs and MRGs were Pseudomonas and Burkholderia, which are important nosocomial pathogens. A substantial phage diversity for pathogenic and putrefying bacteria at all locations attracts attention for its use to tackle the dissemination of antibiotic and metal-resistant bacteria. This study suggests the accumulation of antibiotics and metals as the driving force for the emergence of resistance genes and the affiliated bacteria trafficking them. The present metagenomic assessment highlights the need for comprehensive, long-term biological and physicochemical monitoring and mitigation strategies toward the contaminants associated with ARGs and MRGs in this nationally important river.202336773904
6432150.9998Antibiotic resistance genes in the coastal atmosphere under varied weather conditions: Distribution, influencing factors, and transmission mechanisms. Antibiotic resistance genes (ARGs) have escalated to levels of concern worldwide as emerging environmental pollutants. Increasing evidence suggests that non-antibiotic antimicrobial substances expedite the spread of ARGs. However, the drivers and mechanisms involved in the generation and spread of ARGs in the atmosphere remain inadequately elucidated. Co-occurrence networks, mantel test analysis, and partial least squares path modeling were used to analyze the symbiotic relationships of ARGs with meteorological conditions, atmospheric pollutants, water-soluble inorganic ions, bacteria, mobile genetic elements (MGEs), antibacterial biocide and metal resistance genes, and to identify the direct drivers of ARGs. The types and abundance of ARGs exhibited different seasonal distribution. Specifically, the types exhibited a strong alignment with the diversity of air masses terrestrial sources, while the abundance displayed a significant positive correlation with both biocide resistance genes (BRGs) and metal resistance genes (MRGs). The contribution of bacterial communities and MGEs to the generation and spread of ARGs was constrained by the low levels of antibiotics in the atmosphere and the existence of "viral intermediates". Conversely, antibacterial biocides and metals influenced mutation rates, cellular SOS responses, and oxidative stress of bacteria, consequently facilitating the generation and spread of ARGs. Moreover, the co-selection among their derivatives, resistance genes, ensured a stable presence of ARGs. The research highlighted the significant impact of residual antimicrobial substances on both the generation and spread of ARGs. Elucidating the sources of aerosols and the co-selection mechanism linking with ARGs, BRGs, and MRGs were crucial for preserving the stability of ARGs in the atmosphere.202539824332
6885160.9998Abundant bacteria shaped by deterministic processes have a high abundance of potential antibiotic resistance genes in a plateau river sediment. Recent research on abundant and rare bacteria has expanded our understanding of bacterial community assembly. However, the relationships of abundant and rare bacteria with antibiotic resistance genes (ARGs) remain largely unclear. Here, we investigated the biogeographical patterns and assembly processes of the abundant and rare bacteria from river sediment at high altitudes (Lhasa River, China) and their potential association with the ARGs. The results showed that the abundant bacteria were dominated by Proteobacteria (55.4%) and Cyanobacteria (13.9%), while the Proteobacteria (33.6%) and Bacteroidetes (18.8%) were the main components of rare bacteria. Rare bacteria with a large taxonomic pool can provide function insurance in bacterial communities. Spatial distribution of persistent abundant and rare bacteria also exhibited striking differences. Strong selection of environmental heterogeneity may lead to deterministic processes, which were the main assembly processes of abundant bacteria. In contrast, the assembly processes of rare bacteria affected by latitude were dominated by stochastic processes. Abundant bacteria had the highest abundance of metabolic pathways of potential drug resistance in all predicted functional genes and a high abundance of potential ARGs. There was a strong potential connection between these ARGs and mobile genetic elements, which could increase the ecological risk of abundant taxa and human disease. These results provide insights into sedimental bacterial communities and ARGs in river ecosystems.202236406442
6876170.9998Resistome and microbiome shifts in catfish rearing water: the influence of temperature and antibiotic treatments. The increasing reliance on aquaculture for sustainable protein production highlights the need for responsible antibiotic use to manage bacterial infections, particularly in intensive farming systems. This study investigated the effects of three FDA-approved antibiotics (Aquaflor®, Romet®, Terramycin®) at common fish bacterial disease outbreak temperatures (20 °C, 25 °C, and 30 °C) on the microbiome and resistome of aquaculture water using a catfish model system. Metagenomic analyses evaluated the abundance, diversity, and mobility of antimicrobial resistance genes (ARGs) and antibiotic-resistant bacteria (ARB). The impact of temperature on Aquaflor- and Romet-induced changes in ARG abundance, richness, and resistome composition followed a U-shaped trend, with the least effect observed at 25 °C. Of the three antibiotics tested, Terramycin exerted the most significant influence on the water microbiome and resistome, enriching tetracycline resistance genes and co-selecting for floR, sul, and dfrA genes. Temperature also induced notable shifts in the ARB population, with Mantel tests revealing strong correlations between ARG profiles and changes in the overall bacterial community and ARB populations. While certain ARG classes consistently remained associated with specific host phyla, others shifted, highlighting the potential for horizontal gene transfer (HGT) as a critical mechanism for disseminating resistance genes like tet(C), particularly after antibiotic treatment. This is further supported by the observed reduction in plasmid numbers following treatment, which coincided with increased HGT events. Our findings highlight the pivotal role of temperature in influencing resistome dynamics, emphasizing the importance of accounting for environmental factors when applying antibiotics to effectively mitigate antimicrobial resistance in aquaculture systems.202540578104
3252180.9998Exploring phylogenetic diversity of antibiotic resistance genes in activated sludge: A host and genomic location perspective. Antibiotic resistance has emerged as a significant global public health issue. The environmental behaviors of antibiotic resistance genes (ARGs), such as their persistence and horizontal transfer, have been extensively investigated. However, the genetic diversity characteristics of ARGs remain underexplored, which limits a comprehensive analysis of their roles in the environment. In this study, we examined the genetic diversity of ARGs in activated sludge from 44 wastewater treatment plants in five countries. Most ARGs detected in activated sludge possessed multiple variants, with a median of 48. The number of variants of gd-ARGs varied among different resistance mechanisms and ARG types. The number of potential variants of ARGs was strongly correlated with host diversity. Pseudomonas spp. and Klebsiella pneumoniae, identified as pathogenic bacteria, harbored multiple ARGs and had the most variants. Most ARG subtypes on plasmids and chromosomes showed divergent evolution. Molecular docking of AdeH proteins revealed that genomic location affects tetracycline binding energy. The findings underscore the intricate interplay between genetic variation and environmental adaptation in ARGs, offering a novel perspective on the spread of antibiotic resistance.202540216056
6816190.9998The impact of microplastics on antibiotic resistance genes, metal resistance genes, and bacterial community in aquaculture environment. Microplastics are emerging contaminants. However, their effects on antibiotic resistance genes (ARGs), metal resistance genes (MRGs), and the structure and abundance of bacterial communities, particularly pathogens, in aquaculture environments remains poorly understood. Therefore, this study investigated the effect of microplastics of different sizes on the abundance and distribution of ARGs, MRGs, and bacterial communities in aquaculture environments. The results revealed that, compared with pond water, large microplastics harbored significantly higher ARG abundances, particularly for multidrug-resistant genes; notably, level-I- and -II-risk ARGs were more prevalent on microplastics, highlighting the potential for horizontal gene transfer. Microplastics also exhibited a propensity to aggregate pathogenic bacteria such as Brucella and Pseudomonas, which could pose direct risks to aquatic product safety and public health. Network and differential network analyses revealed significant correlations between bacterial genera and ARG/MRG abundance, particularly on microplastics. Therefore, our findings suggest that microplastics act as vectors for the spread of ARGs, MRGs, and pathogens in aquaculture, potentially leading to the formation of complexes of these materials that threaten ecosystem health and human well-being. This study provides critical insights into the need for targeted management strategies to mitigate microplastic pollution in aquaculture settings.202539987738