Microbiome and antibiotic resistome in household dust from Beijing, China. - Related Documents




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683601.0000Microbiome and antibiotic resistome in household dust from Beijing, China. We spend ever-increasing time indoors along with urbanization; however, the geographical distribution patterns of microbiome and antibiotic resistome, and their driving forces in household environment remains poorly characterized. Here, we surveyed the bacterial and fungal communities, and the resistome in settled dust gathered from 82 homes located across Beijing, China, employing Illumina sequencing and high-throughput quantitative PCR techniques. There was no clear geographical distribution pattern in dust-related bacterial communities although a slight but significant (P < 0.05) distance-decay relationship occurred in its community similarity; by contrast, a relatively distinct geographical clustering and a stronger distance-decay relationship were observed in fungal communities at the local scale. The cross-domain (bacteria versus fungi) relationships in the microbiome of the dust samples were mostly observed as robust co-occurrence correlations. The bacterial communities were dominated by Proteobacteria and Actinobacteria phyla, with human skin, soil and plants being potential major sources. The fungal communities largely comprised potential allergens (a median 61% of the fungal sequences), with Alternaria genus within Ascomycota phylum being the most predominant taxa. The profile of dust-related bacterial communities was mainly affected by housing factors related to occupants and houseplants, while that of fungal communities was determined by georeferenced environmental factors, particularly vascular plant diversity. Additionally, a great diversity (1.96 on average for Shannon index) and normalized abundance (2.22 copies per bacterial cell on average) of antibiotic resistance genes were detected across the dust samples, with the dominance of genes resistant to vancomycin and Macrolide-Lincosamide-Streptogramin B. The resistome profile exhibited no distinct geographical pattern, and was primarily driven by certain bacterial phyla and occupancy-related factors. Overall, we underline the significance of anthropogenic impacts and house location in structuring bacterial and fungal communities inside homes, respectively, and suggest that household dust is an overlooked reservoir for antibiotic resistance.202032248025
321710.9998Distribution and environmental dissemination of antibiotic resistance genes in poultry farms and surrounding ecosystems. Antibiotic resistance poses a significant threat to human and animal health worldwide, with farms serving as crucial reservoirs of Antibiotic Resistance Genes (ARGs) and Antibiotic-resistant bacteria. However, the distribution of ARGs in poultry farms and their transmission patterns in the environment remain poorly understood. This study collected samples of aerosol microorganisms, cloacal matter, soil, and vegetables from poultry farms and surrounding environments at three different distances. We used 16S rRNA gene sequencing and HT-qPCR to analyze the characteristics of aerosol microbial communities and the abundance of ARGs. At the phylum level, Proteobacteria, Firmicutes, and Bacteroidetes were dominant in cloacal samples, aerosol samples, and vegetable samples, while Proteobacteria Actinobacteriota and Acidobacteria dominated soil. Pseudomonas was dominant in cloacal samples at the genus level, whereas Fusobacterium was prevalent in soil. The diversity and richness of bacterial communities were more similar between cloacal samples than those observed between either sample type compared with soil. Our results showed that tetracycline and aminoglycoside ARG relative abundance was high across all sample types but significantly increased within feces/air compared to soils/vegetables. Association analysis revealed five potential host genera for ARG/MGE presence among various microbiota populations studied here. Our findings confirm that farms are important sources for the environmental dissemination of pathogens and ARGs.202539689477
683520.9998Metagenomic profiling of antibiotic resistance genes and their associations with the bacterial community along the Kanda River, an urban river in Japan. Antibiotic resistance genes (ARGs) present in urban rivers have the potential to disseminate antibiotic-resistant bacteria into other environments, posing significant threats to both ecological and public health. Although metagenomic analyses have been widely employed to detect ARGs in rivers, our understanding of their dynamics across different seasons in diverse watersheds remains limited. In this study, we performed a comprehensive genomic analysis of the Kanda River in Japan at 11 sites from upstream to estuary throughout the year to assess the spread of ARGs and their associations with bacterial communities. Analysis of 110 water samples using the 16S rRNA gene revealed variations in bacterial composition corresponding to seasonal changes in environmental parameters along the river. Shotgun metagenomics-based profiling of ARGs in 44 water samples indicated higher ARG abundance downstream, particularly during the summer. Weighted gene co-expression network analysis (WGCNA) linking bacterial lineages and ARGs revealed that 12 ARG subtypes co-occurred with 128 amplicon sequence variants (ASVs). WGCNA suggested potential hosts for ErmB, ErmF, ErmG, tetQ, tet (W/N/W), aadA2, and adeF, including gut-associated bacteria (e.g., Prevotella, Bacteroides, Arcobacter) and indigenous aquatic microbes (e.g., Limnohabitans and C39). In addition, Pseudarcobacter (a later synonym of Arcobater) was identified as a host for adeF, which was also confirmed by single cell genomics. This study shows that ARG distribution in urban rivers is affected by seasonal and geographical factors and demonstrates the importance of monitoring rivers using multiple types of genome sequencing, including 16S rRNA gene sequencing, metagenomics, and single cell genomics.202539488451
685030.9998Fate of high-risk antibiotic resistance genes in large-scale aquaculture sediments: Geographical differentiation and corresponding drivers. Antibiotic resistance genes (ARGs), emerging environmental contaminants, have become challenges of public health security. However, the distribution and drivers of ARGs, especially high-risk ARGs, in large-scale aquaculture sediments remain unknown. Here, we collected sediment samples from 40 crayfish ponds in seven main crayfish culture provinces in China and then investigated the distribution and risk of ARGs based on high-throughput sequencing and quantitative PCR techniques. Our results suggested that aquaculture sediment was potential reservoir of ARGs and the abundance of aadA-02 was the highest. High-risk ARG (floR) was also prevalent in the sediment and was the most abundant in Jiangsu Province, where opportunistic pathogens were also enriched. The abundance of floR was positively correlated with different environmental factors, such as total phosphorus in water and total carbon in sediment. In addition, Mycobacterium sp., opportunistic pathogenic bacteria, might be potential host for floR. Furthermore, the potential propagation pathway of ARGs was from sediment to crayfish gut, and Bacteroidetes and Proteobacteria might be the main bacterial groups responsible for the proliferation of ARGs. Generally, our results illustrate that pond sediment may be an ARG reservoir of aquatic animals. Meanwhile, our study helps develop valuable strategies for accessing risks and managing ARGs.202337714353
321540.9998Prevalence of antibiotic resistance genes its association with microbiota in raw milk of northwest Xinjiang. The issue of antibiotic resistance caused by antibiotic resistance genes (ARGs) has become a significant concern in environmental research in recent years, while raw milk is an important link in the food chain and has become one of the carriers and reservoirs of ARGs, which has not been taken seriously. This research employed high-throughput quantitative PCR and Illumina sequencing techniques targeting the 16S rRNA gene. These methods were used to examine the bacterial community composition and genes associated with antibiotic resistance in raw milk samples collected from the northwestern area of Xinjiang. An aggregate of 31 distinct resistance alleles were identified, with their abundance reaching as high as 3.70 × 10(5) copies per gram in the analyzed raw milk samples. Microorganisms harboring ARGs that confer resistance to beta-lactams, tetracyclines, aminoglycosides, and chloramphenicol derivatives were prevalent in raw milk. Procrustes analysis revealed a certain degree of correlation between the microbial community and the antibiotic resistance gene (ARG) profiles. Furthermore, network analysis demonstrated that Actinobacteria and Firmicutes were the predominant phyla exhibiting co-occurrence relationships with specific ARGs. Combining the findings from Variance Partitioning Analysis (VPA), the distribution of ARGs was mainly driven by three factors: the combined effect of physicochemical properties and mobile genetic elements (MGEs) (33.5%), the interplay between physicochemical parameters and microbial communities (31.8%), and the independent contribution of physicochemical factors (20.7%). The study demonstrates that the overall abundance of ARGs correlates with physicochemical parameters, bacterial community composition, and the presence of MGEs. Furthermore, understanding these associations facilitates the evaluation of antibiotic resistance risks, thereby contributing to enhanced farm management practices and the assurance of food safety.202540718809
321650.9998Effects of different laying periods on airborne bacterial diversity and antibiotic resistance genes in layer hen houses. Poultry farms are a complex environment for close contact between humans and animals. Accumulating evidence has indicated that pathogens and drug resistance genes in chicken houses may pose a serious threat to public health and economic concerns. However, insufficient knowledge of the indoor aerosol microbiome and resistome profiles of layer hen houses hampers the understanding of their health effects. Environmental surveillance of antibiotic resistance may contribute to a better understanding and management of the human exposure risk of bioaerosols under the environmental conditions of chicken houses. In addition, the chicken house has a long operation cycle, and the bacterial diversity and antibiotic resistance genes of aerosols in different periods may be different. In this study, air samples were collected from 18 chicken houses on three farms, including the early laying period (EL), peak laying period (PL), and late laying period (LL). 16S rRNA gene sequencing and metagenomics were used to study the composition of the bacteria and resistome in aerosols of layer hen houses and the results showed that they varied with laying period. The highest alpha diversity of bacteria was observed in PL bioaerosols. The dominant bacterial phyla included Firmicutes, Bacteroidetes and Proteobacteria. Three potential pathogenic bacterial genera (Bacteroides, Corynebacterium and Fusobacterium) were found. The most abundant ARG type was aminoglycosides in all laying periods. In total, 22 possible ARG host genera were detected. ARG subtypes and abundance were both higher in LL. Network analysis also showed higher co-occurrence patterns between the bacteria and resistome in bioaerosols. The laying period plays an important role in the bacterial community and resistome in layer house aerosols.202337119673
680460.9998Seasonal variations of profiles of antibiotic resistance genes and virulence factor genes in household dust from Beijing, China revealed by the metagenomics. Household-related microbiome is closely related with human health. However, the knowledge about profiles of antibiotic resistance genes (ARGs) and virulence factor genes (VFGs) which are carried by microbes inside homes and their temporal dynamics are rather limited. Here we monitored the seasonal changes of bacterial community (especially pathogenic bacteria), ARGs, and VFGs in household dust samples during two years. Based on metagenomic sequencing, the dust-related bacterial pathogenic community, ARGs, and VFGs all harbored the lowest richness in spring among four seasons. Their structure (except that of VFGs) also exhibited remarkable differences among the seasons. The structural variations of ARGs and VFGs were almost explained by mobile genetic elements (MGEs), bacterial pathogens, and particulate matter-related factors, with MGEs explaining the most. Moreover, the total normalized abundance of ARGs or VFGs showed no significant change across the seasons. Results of metagenomic binning and microbial network both showed that several pathogenic taxa (e.g., Ralstonia pickettii) were strongly linked with numerous ARGs (mainly resistant to multidrug) and VFGs (mainly encoding motility) simultaneously. Overall, these findings underline the significance of MGEs in structuring ARGs and VFGs inside homes along with seasonal variations, suggesting that household dust is a neglected reservoir for ARGs and VFGs.202438636860
685270.9998Distribution and co-occurrence patterns of antibiotic resistance genes in black soils in Northeast China. Black soils (Mollisols) are among the most important soil resources for crop production and food security. In China, they are mainly distributed in the northeastern region. To investigate soil antibiotic resistance distribution patterns and monitor soil quality, we randomly chose nine corn fields in Northeast China and analyzed the antibiotic resistance gene (ARG) distribution and co-occurrence patterns on the basis of high-throughput approaches and network analyses. High genetic diversity (136 unique genes) and low ARG abundances (10(-5)-10(-2) copies/16S rRNA gene copy) were detected, with relatively few interactions among ARGs. Type I integron genes were prevalent in the soil and were positively correlated with ARGs, which may increase the risk of ARG transmission. Most ARGs were strongly associated with microorganisms. Moreover, several ARGs were significantly correlated with antibiotics, nutrients, and metal elements. The generation and dissemination of ARGs, which were most likely mediated by mobile genetic elements (MGEs) and bacteria, were affected by environmental conditions. These results provide insights into the widespread co-occurrence patterns in soil resistomes.202235809539
317680.9998Comprehensive profiling and risk assessment of antibiotic resistance genes in a drinking water watershed by integrated analysis of air-water-soil. The prevalence of antibiotic resistance genes (ARGs) in diverse habitats threatens public health. Watersheds represent critical freshwater ecosystems that interact with both the soil and atmosphere. However, a holistic understanding of ARGs distribution across these environmental media is currently inadequate. We profiled ARGs and bacterial communities in air-water-soil in the same watershed area during four seasons using high-throughput qPCR and 16S rRNA gene sequencing. Our findings demonstrated that aminoglycoside resistance genes (58.5%) were dominant in water, and multidrug resistance genes (55.2% and 54.2%) were dominant in soil and air. Five ARGs and nineteen bacterial genera were consistently detected in all samples, were named as shared genes or bacteria. Co-occurrence Network analysis revealed the co-occurrence module of resistance genes, mobile genetic elements (MGEs), and potential bacterial hosts, indicating that shared genes and bacteria may persist and co-spread across different environmental media. The risk assessment framework, based on ARGs' abundance, detection rate, and mobility, identified 33 high-risk ARGs. This is essential to evaluate the health risks of ARGs and to develop strategies to limit the threat of antibiotic resistance. Our study offers new insights into the risks associated with ARGs in the environment and suggests that ARGs may depend on specific bacterial cohabitants that co-exist with MGEs to facilitate their spread across environmental interfaces.202337742410
323590.9998Vertical distribution of antibiotic resistance genes in an urban green facade. The phyllosphere is considered a key site for the transfer of both naturally and anthropogenically selected antimicrobial resistance genes (ARGs) to humans. Consequently, the development of green building systems may pose an, as yet, unexplored pathway for ARGs and pathogens to transfer from the environment to outdoor plants. We collected leaves from plants climbing up buildings at 1, 2, 4 and 15 m above ground level and collected associated dust samples from adjacent windowsills to determine the diversity and relative abundance of microbiota and ARGs. Overall, a total of 143 ARGs from 11 major classes and 18 mobile genetic elements (MGEs) were detected. The relative abundance of ARGs within the phyllosphere decreased with increasing height above ground level. Fast expectation-maximization microbial source tracking (FEAST) suggested that the contribution of soil and aerosols to the phyllosphere microbiome was limited. A culture-dependent method to isolate bacteria from plant tissues identified a total of 91 genera from root, stem, and leaf samples as well as endophytes isolated from leaves. Of those bacteria, 20 isolates representing 9 genera were known human pathogenic members to humans. Shared bacterial from culture-dependent and culture-independent methods suggest microorganisms may move from soil to plant, potentially through an endophytic mechanism and thus, there is a clear potential for movement of ARGs and human pathogens from the outdoor environment.202133721724
6862100.9998Strong variation in sedimental antibiotic resistomes among urban rivers, estuaries and coastal oceans: Evidence from a river-connected coastal water ecosystem in northern China. Sediment is thought to be a vital reservoir to spread antibiotic resistance genes (ARGs) among various natural environments. However, the spatial distribution patterns of the sedimental antibiotic resistomes around the Bohai Bay region, a river-connected coastal water ecosystem, are still poorly understood. The present study conducted a comprehensive investigation of ARGs among urban rivers (UR), estuaries (ES) and Bohai Bay (BHB) by metagenomic sequencing. Overall, a total of 169 unique ARGs conferring resistance to 15 antimicrobial classes were detected across all sediment samples. The Kruskal-Wallis test showed that the diversity and abundance of ARGs in the UR were all significantly higher than those in the ES and BHB (p < 0.05 and p < 0.01), revealing the distance dilution of the sedimental resistomes from the river to the ocean. Multidrug resistance genes contained most of the ARG subtypes, whereas rifamycin resistance genes were the most abundant ARGs in this region. Our study demonstrated that most antimicrobial resistomes were highly accumulated in urban river sediments, whereas beta-lactamase resistance genes (mainly PNGM-1) dramatically increased away from the estuary to the open ocean. The relative abundance of mobile genetic elements (MGEs) also gradually decreased from rivers to the coastal ocean, whereas the difference in pathogenic bacteria was not significant in the three classifications. Among MGEs, plasmids were recognized as the most important carriers to support the horizontal gene transfer of ARGs within and between species. According to co-occurrence networks, pathogenic Proteobacteria, Actinobacteria, and Bacteroidetes were recognized as potential and important hosts of ARGs. Heavy metals, pH and moisture content were all recognized as the vital environmental factors influencing the distribution of ARGs in sediment samples. Overall, the present study may help to understand the distribution patterns of ARGs at a watershed scale, and help to make effective policies to control the emergence, spread and evolution of different ARG subtypes in different habitats.202337263036
7173110.9997Animal farms are hot spots for airborne antimicrobial resistance. Animal farms are known reservoirs for environmental antimicrobial resistance (AMR). However, knowledge of AMR burden in the air around animal farms remains disproportionately limited. In this study, we characterized the airborne AMR based on the quantitative information of 30 antimicrobial resistance genes (ARGs), four mobile genetic elements (MGEs), and four human pathogenic bacteria (HPBs) involving four animal species from 20 farms. By comparing these genes with those in animal feces, the distinguishing features of airborne AMR were revealed, which included high enrichment of ARGs and their potential mobility to host HPBs. We found that depending on the antimicrobial class, the mean concentration of airborne ARGs in the animal farms ranged from 10(2) to 10(4) copies/m(3) and was accompanied by a considerable intensity of MGEs and HPBs (approximately 10(3) copies/m(3)). Although significant correlations were observed between the ARGs and bacterial communities of air and fecal samples, the abundance of target genes was generally high in fine inhalable particles (PM2.5), with an enrichment ratio of up to 10(2) in swine and cattle farms. The potential transferability of airborne ARGs was universally strengthened, embodied by a pronounced co-occurrence of ARGs-MGEs in air compared with that in feces. Exposure analysis showed that animal farmworkers may inhale approximately 10(4) copies of human pathogenic bacteria-associated genera per day potentially carrying highly transferable ARGs, including multidrug resistant Staphylococcus aureus. Moreover, PM2.5 inhalation posed higher human daily intake burdens of some ARGs than those associated with drinking water intake. Overall, our findings highlight the severity of animal-related airborne AMR and the subsequent inhalation exposure, thus improving our understanding of the airborne flow of AMR genes from animals to humans. These findings could help develop strategies to mitigate the human exposure and dissemination of ARGs across different media.202235985594
3228120.9997Differences in Gut Microbiome Composition and Antibiotic Resistance Gene Distribution between Chinese and Pakistani University Students from a Common Peer Group. Gut microbiomes play important functional roles in human health and are also affected by many factors. However, few studies concentrate on gut microbiomes under exercise intervention. Additionally, antibiotic resistance genes (ARGs) carried by gut microbiomes may constantly pose a threat to human health. Here, ARGs and microbiomes of Chinese and Pakistanis participants were investigated using 16S rRNA gene sequencing and high-throughput quantitative PCR techniques. The exercise had no impact on gut microbiomes in the 12 individuals investigated during the observation period, while the different distribution of gut microbiomes was found in distinct nationalities. Overall, the dominant microbial phyla in the participants' gut were Bacteroidota, Firmicutes and Proteobacteria. Some genera such as Prevotella and Dialister were more abundant in Pakistani participants and some other genera such as Bacteroides and Faecalibacterium were more abundant in Chinese participants. The microbial diversity in Chinese was higher than that in Pakistanis. Furthermore, microbial community structures were also different between Chinese and Pakistanis. For ARGs, the distribution of all detected ARGs is not distinct at each time point. Among these ARGs, floR was distributed differently in Chinese and Pakistani participants, and some ARGs such as tetQ and sul2 are positively correlated with several dominant microbiomes, particularly Bacteroidota and Firmicutes bacteria that did not fluctuate over time.202134072124
7372130.9997Variability of faecal microbiota and antibiotic resistance genes in flocks of migratory gulls and comparison with the surrounding environment. Gulls commonly rely on human-generated waste as their primary food source, contributing to the spread of antibiotic-resistant bacteria and their resistance genes, both locally and globally. Our understanding of this process remains incomplete, particularly in relation to its potential interaction with surrounding soil and water. We studied the lesser black-backed gull, Larus fuscus, as a model to examine the spatial variation of faecal bacterial communities, antibiotic resistance genes (ARGs), and mobile genetic elements (MGEs) and its relationship with the surrounding water and soil. We conducted sampling campaigns within a connectivity network of different flocks of gulls moving across functional units (FUs), each of which represents a module of highly interconnected patches of habitats used for roosting and feeding. The FUs vary in habitat use, with some gulls using more polluted sites (notably landfills), while others prefer more natural environments (e.g., wetlands or beaches). Faecal bacterial communities in gulls from flocks that visit and spend more time in landfills exhibited higher richness and diversity. The faecal microbiota showed a high compositional overlap with bacterial communities in soil. The overlap was greater when compared to landfill (11%) than to wetland soils (6%), and much lower when compared to bacterial communities in surrounding water (2% and 1% for landfill and wetland water, respectively). The relative abundance of ARGs and MGEs were similar between FUs, with variations observed only for specific families of ARGs and MGEs. When exploring the faecal carriage of ARGs and MGEs in bird faeces relative to soil and water compartments, gull faeces were enriched in ARGs classified as High-Risk. Our results shed light on the complex dynamics of antibiotic resistance spread in wild bird populations, providing insights into the interactions among gull movement and feeding behavior, habitat characteristics, and the dissemination of antibiotic resistance determinants across environmental reservoirs.202439019307
6867140.9997Comparative analysis of characteristics of antibiotic resistomes between Arctic soils and representative contaminated samples using metagenomic approaches. Antibiotic resistance is one of the most concerned global health issues. However, comprehensive profiles of antibiotic resistance genes (ARGs) in various environmental settings are still needed to address modern antibiotic resistome. Here, Arctic soils and representative contaminated samples from ARG pollution sources were analyzed using metagenomic approaches. The diversity and abundance of ARGs in Arctic soils were significantly lower than those in contaminated samples (p < 0.01). ARG profiles in Arctic soils were featured with the dominance of vanF, ceoB, and bacA related to multidrug and bacitracin, whereas those from ARG pollution sources were characterized by prevalent resistance to anthropogenic antibiotics such as sulfonamides, tetracyclines, and beta-lactams. Mobile genetic elements (MGEs) were found in all samples, and their abundance and relatedness to ARGs were both lower in Arctic soils than in polluted samples. Significant relationships between bacterial communities and ARGs were observed (p < 0.01). Cultural bacteria in Arctic soils had clinically-concerned resistance to erythromycin, vancomycin, ampicillin, etc., but ARGs relevant to those antibiotics were undetectable in their genomes. Our results suggested that Arctic environment could be an important reservoir of novel ARGs, and antibiotic stresses could cause ARG pollution via horizontal gene transfer and enrichment of resistant bacteria.202438452676
6886150.9997Bacterial community and antibiotic resistance genes assembly processes were shaped by different mechanisms in the deep-sea basins of the Western Pacific Ocean. As the intrinsic property of microorganisms, antibiotic resistance genes (ARGs) are fundamentally coupled to microbially-linked biogeochemical processes within ecosystems. However, human activities often obscure the natural distribution of ARGs through deterministic selective pressures. The deep-sea basin of the western Pacific Ocean is one of the least disturbed areas globally by human activities, providing a natural laboratory to investigate the intrinsic mechanisms governing ARGs in natural environments. In this study, we analyzed bacterial community and ARG diversity in 15 surface sediment samples from three deep-sea basins in the western Pacific Ocean. The relative abundance of ARGs in the surface sediments ranged from 3.10 × 10(-3) to 5.37 × 10(-2) copies/16S rRNA copies, with multidrug and β-lactam resistance genes dominated in all samples (49.06%-100%). The bacteria were mainly dominated by the Proteobacteria. The principal coordinate analysis (PCoA) showed significant spatial heterogeneity of ARGs and bacteria among the three basins. Null model, neutral community models (NCM), and normalized stochasticity ratio (NST) indicated that bacterial community was dominated by stochastic assembly, driven by geographic barriers leading to independent evolution. Conversely, the NST revealed that the ARGs profile was mainly shaped by deterministic processes. Environmental factors are more crucial than geographical factors and bacterial community for ARG occurrence among the selected factors. Meanwhile, we found that the spread of ARGs was mainly through vertical gene transfer in the pre-antibiotic era. The disparity between the assembly processes of bacterial community and ARGs may be attributed to the fact that ARG hosts were not the dominant bacteria in the community. This study first reported the distribution and assembly processes of ARGs and bacterial community in surface sediments of the western Pacific.202439481517
3218160.9997Airborne bacterial communities in the poultry farm and their relevance with environmental factors and antibiotic resistance genes. The accelerating occurrence and environmental dissemination of bacteria, gas pollutants and antibiotic resistance genes (ARGs) in aerosols of poultry farms have become emerging environmental issues due to their potential threat to animals, workers, and the communities located near such farms. Here, aerosol samples were gathered from inside and outside of the chicken house in winter with a transportable high-flow bioaerosol sampler. Then, 16S rRNA gene amplicon sequencing was used to categorize the bacteria in air samples, and the abundance of 12 ARG subtypes was researched via the real-time quantitative polymerase chain reaction (qPCR). Results indicated that the bacterial richness and diversity and total absolute abundance of ARGs were similar in the bioaerosols from indoor and downwind site of the poultry farm. The zoonotic pathogens, Staphylococcus and Corynebacterium, were detected both inside and outside of the chicken house, and the four most abundant target genes were bla(TEM), tetQ, ermB and sul1 in aerosols. Moreover, the correlation between the bacterial communities and environmental factors, such as NH(3) and H(2)S concentrations, wind speed, temperature and relative humidity, was analyzed. The result revealed that the indoor bacteria community was positively associated with temperature and concentrations of air pollutants (NH(3) and H(2)S), and could spread from confinement buildings to the ambient atmosphere through wind. In addition, the network analysis result showed that the airborne bacteria might significantly contribute in shaping the ARGs' profiles in bioaerosol from inside and outside of the poultry house. Overall, our results revealed the airborne bacterial communities and their associated influencing factors in the micro-environment (inside of the chicken house and nearby the boundary of the farm), and brought a new perspective for studying the gas pollutants and bioaerosol from poultry farms in winter.202235850323
7371170.9997Plastisphere and the occurrence of antibiotic resistance in a 40-year-old abandoned coastal landfill site in Chile. Plastispheres are microbial communities that inhabit plastic surfaces and have been extensively studied in aquatic environments. However, little is known about their occurrence in landfills. We investigated plastisphere communities in a 40-year-old coastal abandoned landfill in Rocuant-Andalién, Chile, and aimed to characterize landfill plastisphere communities and assess their potential role as reservoirs of antibiotic resistance genes (ARGs). High-density polyethylene was the predominant plastic type (56 %). Microscopy revealed diverse bacterial morphotypes, including bacilli, cocci, and filamentous forms, forming clusters on plastic surfaces. 16S rRNA gene sequencing revealed that Actinobacteria, Firmicutes, and Proteobacteria dominated most samples, with high overall diversity and richness. Beta diversity analysis indicated significant variation in bacterial communities among sites but not among polymer types. Notably, the intI1 gene, associated with the spread of antibiotic resistance, was detected at 67 % of the sampled sites. These findings reveal that landfills act as reservoirs for a wide range of bacteria, some of which may have clinical significance, highlighting their ecological and public health impact. Furthermore, plastics are likely to transport resistance genes originating from human activities, spreading them into nearby ecosystems, such as wetlands and oceans, where they interact with wildlife.202541109620
3205180.9997Determinants for antimicrobial resistance genes in farm dust on 333 poultry and pig farms in nine European countries. Livestock feces with antimicrobial resistant bacteria reaches the farm floor, manure pit, farm land and wider environment by run off and aerosolization. Little research has been done on the role of dust in the spread of antimicrobial resistance (AMR) in farms. Concentrations and potential determinants of antimicrobial resistance genes (ARGs) in farm dust are at present not known. Therefore in this study absolute ARG levels, representing the levels people and animals might be exposed to, and relative abundances of ARGs, representing the levels in the bacterial population, were quantified in airborne farm dust using qPCR. Four ARGs were determined in 947 freshly settled farm dust samples, captured with electrostatic dustfall collectors (EDCs), from 174 poultry (broiler) and 159 pig farms across nine European countries. By using linear mixed modeling, associations with fecal ARG levels, antimicrobial use (AMU) and farm and animal related parameters were determined. Results show similar relative abundances in farm dust as in feces and a significant positive association (ranging between 0.21 and 0.82) between the two reservoirs. AMU in pigs was positively associated with ARG abundances in dust from the same stable. Higher biosecurity standards were associated with lower relative ARG abundances in poultry and higher relative ARG abundances in pigs. Lower absolute ARG levels in dust were driven by, among others, summer season and certain bedding materials for poultry, and lower animal density and summer season for pigs. This study indicates different pathways that contribute to shaping the dust resistome in livestock farms, related to dust generation, or affecting the bacterial microbiome. Farm dust is a large reservoir of ARGs from which transmission to bacteria in other reservoirs can possibly occur. The identified determinants of ARG abundances in farm dust can guide future research and potentially farm management policy.202235033551
7285190.9997Human Activity Determines the Presence of Integron-Associated and Antibiotic Resistance Genes in Southwestern British Columbia. The dissemination of antibiotic resistant bacteria from anthropogenic sources into the environment poses an emerging public health threat. Antibiotic resistance genes (ARGs) and gene-capturing systems such as integron-associated integrase genes (intI) play a key role in alterations of microbial communities and the spread of antibiotic resistant bacteria into the environment. In order to assess the effect of anthropogenic activities on watersheds in southwestern British Columbia, the presence of putative antibiotic resistance and integrase genes was analyzed in the microbiome of agricultural, urban influenced, and protected watersheds. A metagenomics approach and high-throughput quantitative PCR (HT qPCR) were used to screen for elements of resistance including ARGs and intI. Metagenomic sequencing of bacterial genomic DNA was used to characterize the resistome of microbial communities present in watersheds over a 1-year period. There was a low prevalence of ARGs relative to the microbial population (<1%). Analysis of the metagenomic sequences detected a total of 60 elements of resistance including 46 ARGs, intI1, and groEL/intI1 genes and 12 quaternary ammonium compounds (qac) resistance genes across all watershed locations. The relative abundance and richness of ARGs was found to be highest in agriculture impacted watersheds compared to urban and protected watersheds. A downstream transport pattern was observed in the impacted watersheds (urban and agricultural) during dry months. Similar to other reports, this study found a strong association between intI1 and ARGs (e.g., sul1), an association which may be used as a proxy for anthropogenic activities. Chemical analysis of water samples for three major groups of antibiotics was below the detection limit. However, the high richness and gene copy numbers (GCNs) of ARGs in impacted sites suggest that the effects of effluents on microbial communities are occurring even at low concentrations of antimicrobials in the water column. Antibiotic resistance and integrase genes in a year-long metagenomic study showed that ARGs were driven mainly by environmental factors from anthropogenized sites in agriculture and urban watersheds. Environmental factors such as land-use and water quality parameters accounted for 45% of the variability observed in watershed locations.201829765365