Mitigating the risk of antibiotic resistance and pathogenic bacteria in swine waste: The role of ectopic fermentation beds. - Related Documents




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716101.0000Mitigating the risk of antibiotic resistance and pathogenic bacteria in swine waste: The role of ectopic fermentation beds. The ectopic fermentation bed (EFB) is used to recycle animal waste, but the fate and dynamic change of antibiotic resistance genes (ARGs) with biocide or heavy metal resistance genes (B/MRGs) and pathogens remain unclear. We performed metagenomic sequencing on 129 samples to study the resistome and bacteriome in pig feces from 24 farms, comparing these profiles with EFBs from five farms, and one farm's EFB was monitored for 154 days. Results showed pig feces from different cities (Chengdu, Meishan, and Chongqing) shared 284 of 311 ARG subtypes, with over 70 % being high-risk ARGs, and 106 of 114 pathogenic bacteria. Swine farms were heavily contaminated with co-occurrences of risky ARGs, B/MRGs, and pathogenic hosts, particularly Escherichia coli and Streptococcus suis being hosts of multidrug ARGs. The application of EFBs markedly mitigated these risks in feces, showing a 3.09-fold decrease in high-risk ARGs, a 72.22 % reduction in B/MRGs, a 3.95-fold drop in prioritized pathogens, an 89.09 % decline in the relative abundance of pig pathogens, and a simplification of their correlation networks and co-occurrence patterns. A mantel analysis revealed that metal contents (Fe, Mn, and Cu) and time influenced pathogen and ARG profiles. Pathogens, ARGs, and risk ARGs exhibited periodic variations, peaking at days 14, 84, and 154, with 70-day intervals. This study provides a comprehensive assessment of the risks associated with pig feces and EFBs and demonstrates that EFBs reduce ARG risks by inhibiting their associations with B/MRGs and pathogens. These findings can help guide and improve the management of antimicrobial resistance and pathogenic contaminants in EFB applications to reduce environmental pollution.202540220395
686610.9996Deciphering the antibiotic resistome in stratified source water reservoirs in China: Distribution, risk, and ecological drive. The proliferation and dissemination of antibiotic resistance genes (ARGs) in source water reservoirs may pose a threat to human health. This study investigated the antibiotic resistance in stratified reservoirs in China across different seasons and spatial locations. In total, 120 ARG subtypes belonging to 15 ARG types were detected with an abundance ranging from 171.06 to 793.71 × /Gb. Multidrug, tetracycline, aminoglycoside, and bacitracin resistance genes were dominant in the reservoirs. The abundance and transfer potential of ARGs were notably higher, especially during the stratified period, with markedly elevated levels in the bottom layer compared to the surface layer. Metagenomic assembly yielded 1357 ARG-carrying contigs, belonging to 83 resistant bacterial species, of which 13 were identified as human pathogen bacteria (HPB). HPB hosts (Sphingomonas sp., Burkholderiales sp., and Ralstonia sp., etc.) were super carriers of ARGs. Genes including ompR, bacA, golS, and ugd carried on HPB plasmids exhibited higher abundance in the water, warranting attention to the risk of resistance transmission. Environmental pressures have caused a shift in the assembly mechanism of ARGs, transitioning from a random process in surface water to a deterministic process in bottom water. The results of this study will deepen people's understanding of the ARG risk in stratified reservoirs.202539673943
717420.9995Metagenomic analysis deciphers airborne pathogens with enhanced antimicrobial resistance and virulence factors in composting facilities. The composting process has been shown to effectively reduce antimicrobial resistance (AMR) in animal manure, but its influence on surrounding airborne AMR remains unknown, particularly with regard to human-pathogenic antibiotic-resistant bacteria (HPARB). In this study, air and paired compost samples were collected from a full-scale composting facility, and the antibiotic resistome, microbiome, and HPARB were systematically analyzed in both two habitats using metagenomic analysis. Current result uncovered the profiles of HPARB in air, showing that significantly more airborne HPARB were assembled than that in compost samples. Airborne pathogens harboredan increased abundance and diversity of antibiotic resistance genes (ARGs) and virulence factor genes (VFGs) in comparison with compost-borne HPARB. The core antibiotic resistome represents 18.58% of overall ARG subtypes, contributing to 86.31% of ARG abundance. A higher number of enriched core ARGs (2.16- to 13.36-times higher), including mexF, tetW, and vanS, were observed in air samples compared to compost samples. As an important human pathogen, Mycobacterium tuberculosis was prevalent in the air and carried more ARG (6) and VFG (130) subtypes than those in compost. A significantly higher risk score was detected for airborne AMR in the composting facility compared to that in hospital and urban environments. This study revealed the enhanced airborne HPARB through comparative experiments between air and composting habitats. It highlighted the unrecognized AMR risks associated with air in composting site and provided a scientific basis for accurately assessing health outcomes caused by occupational exposure.202540472755
685430.9995Characteristics and driving factors of antibiotic resistance genes in aquaculture products from freshwater ponds in China Yangtze River Delta. Antibiotic resistance genes (ARGs) are widespread in aquaculture and pose a huge threat to aquaculture organisms and human health. In this study, occurrences and relative abundances of ARGs were analysed in the guts of products cultured in freshwater ponds in the Yangtze River Delta region in China. A total of 29 ARGs were found in the gut samples, with detection frequencies ranging from 4.8% to 81%, and the relative abundances (ARGs/16S rRNA) ranging from 10(-7) to 1. In addition, the human dietary intake of ARGs via aquaculture products was assessed, where the daily intake of most ARGs via aquaculture products was higher than those via PM2.5 and drinking water, but lower than that via vegetables. The relative abundances of MGE (IS613, Tp614, tnpA and int1) were significantly correlated with those of multiple ARGs, indicating the horizontal gene transfer (HGT) of ARGs among gut microorganisms. Proteobacteria, Firmicutes and Actinobacteria were the dominated microbial communities found in the guts of aquaculture products. In addition, significant correlations were found between Cyanobacteria and int1, between Nitrospira and tetE, and between sul2 and aadA2, indicating potential same hosts of these genes. In addition, results from co-correlation indicated both HGT (dominated by MGEs) of ARGs and the enrichment of ARGs in bacteria. MGEs, mostly int1, were more effective than bacteria in increasing the ARG abundance. This study could provide a better understanding of the transmission of ARGs in the aquaculture environment and improve the quality of aquaculture products and the ecology.202436756971
717340.9995Animal 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
683950.9995Bioaerosol is an important transmission route of antibiotic resistance genes in pig farms. Although pig farms are hotspots of antibiotic resistance due to intensive use of antibiotics, little is known about the abundance, diversity and transmission of airborne antibiotic resistance genes (ARGs). This study reports that bioaerosol is an important spread route of ARGs in pig farms. ARGs, mobile genetic elements (MGEs), and bacterial communities were investigated in both air and feces samples during winter and summer. The average concentration of airborne ARGs and MGEs during winter is higher than that during summer when using the ventilation system. The tetM is identified as the predominant airborne ARG with abundance of 6.3 ± 1.2 log copies/m(3). Clostridium and Streptococcus are two dominant bacteria and several opportunistic pathogens are detected in air samples. High temperature is favorable for more diverse bacterial communities, but relative humidity has negative effects. The wind speed promotes the spread of airborne ARGs. The network analysis results show the average fecal contribution to airborne bacteria is 19.9% and 59.4% during summer and winter, respectively. Horizontal gene transfer plays an important role in the dissemination of airborne ARGs during winter (77.8% possibility), while a lower possibility of 12.0% in summer.202133864959
685760.9995Metagenomic analysis reveals patterns and hosts of antibiotic resistance in different pig farms. In actual production environments, antibiotic-resistant genes (ARGs) are abundant in pig manure, which can form transmission chains through animals, the environment, and humans, thereby threatening human health. Therefore, based on metagenomic analysis methods, ARGs and mobile genetic elements (MGEs) were annotated in pig manure samples from 6 pig farms in 3 regions of Shanxi Province, and the potential hosts of ARGs were analyzed. The results showed that a total of 14 ARG types were detected, including 182 ARG subtypes, among which tetracycline, phenol, aminoglycoside, and macrolide resistance genes were the main ones. ARG profiles, MGE composition, and microbial communities were significantly different in different regions as well as between different pig farms. In addition, Anaerobutyricum, Butyrivibrio, and Turicibacter were significantly associated with multiple ARGs, and bacteria such as Prevotella, Bacteroides, and the family Oscillospiraceae carried multiple ARGs, suggesting that these bacteria are potential ARG hosts in pig manure. Procrustes analysis showed that bacterial communities and MGEs were significantly correlated with ARG profiles. Variation partitioning analysis results indicated that the combined effect of MGEs and bacterial communities accounted for 64.08% of resistance variation and played an important role in ARG profiles. These findings contribute to our understanding of the dissemination and persistence of ARGs in actual production settings, and offer some guidance for the prevention and control of ARGs contamination.202336826766
716370.9995Prevalence of antibiotic resistance genes and bacterial pathogens in long-term manured greenhouse soils as revealed by metagenomic survey. Antibiotic resistance genes (ARGs), human pathogenic bacteria (HPB), and HPB carrying ARGs pose a high risk to soil ecology and public health. Here, we used a metagenomic approach to investigate their diversity and abundance in chicken manures and greenhouse soils collected from Guli, Pulangke, and Hushu vegetable bases with different greenhouse planting years in Nanjing, Eastern China. There was a positive correlation between the levels of antibiotics, ARGs, HPB, and HPB carrying ARGs in manures and greenhouse soils. In total, 156.2–5001.4 μg/kg of antibiotic residues, 22 classes of ARGs, 32 HPB species, and 46 species of HPB carrying ARGs were found. The highest relative abundance was tetracycline resistance genes (manures) and multidrug resistance genes (greenhouse soils). The dominant HPB and HPB carrying ARGs in the manures were Bacillus anthracis, Bordetella pertussis, and B. anthracis (sulfonamide resistance gene, sul1), respectively. The corresponding findings in greenhouse soils were Mycobacterium tuberculosis and M. ulcerans, M. tuberculosis (macrolide-lincosamide-streptogramin resistance protein, MLSRP), and B. anthracis (sul1), respectively. Our findings confirmed high levels of antibiotics, ARGs, HPB, and HPB carrying ARGs in the manured greenhouse soils compared with those in the field soils, and their relative abundance increased with the extension of greenhouse planting years.201525514174
683880.9995Seasonal variation characteristics of inhalable bacteria in bioaerosols and antibiotic resistance genes in Harbin. Bioaerosols have received extensive attention due to their impact on climate, ecological environment, and human health. This study aimed to reveal the driving factors that structure bacterial community composition and the transmission route of antibiotic resistance genes (ARGs) in PM(2.5). The results showed that the bacterial concentration in spring (8.76 × 10(5) copies/m(3)) was significantly higher than that in summer (1.03 × 10(5) copies/m(3)) and winter (4.74 × 10(4) copies/m(3)). Low temperatures and air pollution in winter negatively affected bacterial concentrations. Keystone taxa were identified by network analysis. Although about 50 % of the keystone taxa had low relative abundances, the strong impact of complex interactions between keystone taxa and other taxa on bacterial community structure deserved attention. The bacterial community assembly was dominated by stochastic processes (79.3 %). Interactions between bacteria and environmental filtering together affected bacterial community composition. Vertical gene transfer played an important role in the transmission of airborne ARGs. Given the potential integration and expression of ARGs in recipients, the human exposure risk due to high concentrations of ARGs and mobile genetic elements cannot be ignored. This study highlights human exposure to inhalable bacterial pathogens and ARGs in urban areas.202336584645
685690.9995Effects of the coexistence of antibiotics and heavy metals on the fate of antibiotic resistance genes in chicken manure and surrounding soils. Both heavy metals and antibiotics exert selection pressure on bacterial resistance, and as they are commonly co-contaminated in the environment, they may play a larger role in bacterial resistance. This study examined how breeding cycles affect antibiotic resistance genes (ARGs) in chicken manure and the surrounding topsoils at 20, 50, 100, 200, and 300 m from twelve typical laying hen farms in the Ningxia Hui Autonomous Region of northwest China. Six antibiotics, seven heavy metals, ten mobile genetic elements (MGEs), and microbial community affected the ARGs profile in chicken dung and soil samples. Tetracycline antibiotic residues were prevalent in chicken manure, as were relatively high content of aureomycin during each culture period. Zinc (Zn) content was highest among the seven heavy metals in chicken feces. Chicken dung also enriched aminoglycosides, MLSB, and tetracycline ARGs, notably during brooding and high production. The farm had a minimal influence on antibiotics in the surrounding soil, but its effect on ARGs and MGEs closer to the farm (50 m) was stronger, and several ARGs and MGEs increased with distance. Manure microbial composition differed dramatically throughout breeding cycles and sampling distances. ARGs were more strongly related with antibiotics and heavy metals in manure than soil, whereas MGEs were the reverse. Antibiotics, heavy metals, MGEs, and bacteria in manure accounted 12.28%, 22.25%, 0.74%, and 0.19% of ARGs composition variance, respectively, according to RDA and VPA. Bacteria (2.89%) and MGEs (2.82%) only affected soil ARGs composition. These findings showed that heavy metals and antibiotics are the main factors affecting faecal ARGs and bacteria and MGEs soil ARGs. This paper includes antibiotic resistance data for large-scale laying hen husbandry in northwest China and a theoretical framework for decreasing antibiotic resistance.202337586197
3206100.9995High pollution and health risk of antibiotic resistance genes in rural domestic sewage in southeastern China: A study combining national-scale distribution and machine learning. Rural domestic sewage has emerged as an important reservoir of antibiotic resistance genes (ARGs) under rapid urbanization, while the national-scale geographical patterns and risks of ARGs remaining unclear. We investigated ARG pollution in rural domestic sewage across 39 sites in 22 Chinese provinces using metagenomic sequencing, identifying 702 ARG subtypes across 21 types. Multidrug resistance genes were predominant in the shared ARGs, accounting for 58.96 % of the total ARG abundance. Host bacteria analysis revealed Klebsiella pneumoniae and Escherichia coli were the main pathogenic-resistant bacteria. Southeastern China exhibited the highest level of ARG pollution in rural domestic sewage, followed by south-central, northern, and western. This ARG pollution was primarily caused by human/animal feces based on ARG indicators. Partial least-squares path model and partial redundancy analysis highlighted antibiotics as the primary driver, explaining 24.16 % of ARG variation, with sulfamethazine, norfloxacin, and ofloxacin identified as priority control targets. Risk assessment by calculating the risk index indicated 24.58 % of detected ARGs posed potential health threats, particularly multidrug resistance. Machine learning models predicted higher ARG risks in rural domestic sewage from southeastern China with intensive human activity. This study underscores the crucial impact of antibiotics in ARG proliferation and risk in rural domestic sewage.202540701495
7152110.9995Aerosolization behavior of antimicrobial resistance in animal farms: a field study from feces to fine particulate matter. Antibiotic resistance genes (ARGs) and antibiotic-resistant bacteria (ARB) in animal feces can be released into the atmosphere via aerosolization, posing a high health risk to farm workers. So far, little attention has been paid to the characterization of the aerosolization process. In this study, fecal and fine particulate matter (PM2.5) samples were collected from 20 animal farms involving swine, cattle, layers, and broilers, and the ARGs, ARB, and human pathogenic bacteria (HPB) were loaded in these two media. The results showed that approximately 70% of ARGs, 60% of ARBs, and 43% of HPBs were found to be preferential aerosolization. The bioaerosolization index (BI) of target 30 ARGs varied from 0.04 to 460.07, and the highest value was detected from tetW. The highest BI values of erythromycin- and tetracycline-resistant bacteria were for Kocuria (13119) and Staphylococcus (24746), respectively, and the distribution of BI in the two types of dominant ARB was similar. Regarding the bioaerosolization behavior of HPB, Clostridium saccharolyticum WM1 was the most easily aerosolized pathogen in swine and broiler farms, and Brucella abortus strain CNM 20040339 had the highest value in cattle and layer farms. Notably, the highest BI values for ARGs, ARB, and HPB were universally detected on chicken farms. Most ARGs, ARB, and HPB positively correlated with animal age, stocking density, and breeding area. Temperature and relative humidity have significant effects on the aerosolization behavior of targets, and the effects of these two parameters on the same target are usually opposite. The results of this study provide a basis for a better understanding of the contribution of animal feces to airborne ARGs and HPBs in farms, as well as for controlling the transport of the fecal microbiome to the environment through the aerosolization pathway.202337152737
7162120.9995Dissemination of antibiotic resistance genes and human pathogenic bacteria from a pig feedlot to the surrounding stream and agricultural soils. The dissemination of antibiotic resistance genes (ARGs), human pathogenic bacteria (HPB), and antibiotic-resistant HPB (ARHPB) from animal feedlot to nearby environment poses a potentially high risk to environmental ecology and public health. Here, a metagenomic analysis was employed to explore the dissemination of ARGs, HPB, and ARHPB from a pig feedlot to surrounding stream and agricultural soils. In total, not detectable (ND)-1,628.4 μg/kg of antibiotic residues, 18 types of ARGs, 48 HPB species, and 216 ARB isolates were detected in all samples. Antibiotic residues from pig feedlot mainly migrated into stream sediments and greenhouse soil. The dominant ARGs and HPB species from pig feedlot spread into stream sediments (tetracycline resistance genes, Clostridium difficile, and Mycobacterium tuberculosis), stream water (multidrug resistance (MDR) genes, Shigella flexneri, and Bordetella pertussis), and greenhouse soil (MDR genes, Bacillus anthracis, and Brucella melitensis). It is concerning that 54.4% of 216 ARB isolates from all samples were potential ARHPB species, and genome sequencing and functional annotation of 4 MDR HPB isolates showed 9 ARG types. Our findings revealed the potential migration and dissemination of antibiotic residues, ARGs, HPB, and ARHPB from pig feedlot to surrounding stream and agricultural soils via pig sewage discharge and manure fertilization.201829860105
6837130.9995Coexistence of antibiotic resistance genes, fecal bacteria, and potential pathogens in anthropogenically impacted water. Microbial indicators are often used to monitor microbial safety of aquatic environments. However, information regarding the correlation between microbial indicators and ecotoxicological factors such as potential pathogens and antibiotic resistance genes (ARGs) in anthropogenically impacted waters remains highly limited. Here, we investigated the bacterial community composition, potential pathogens, ARGs diversity, ARG hosts, and horizontal gene transfer (HGT) potential in urban river and wastewater samples from Chaohu Lake Basin using 16S rRNA and metagenomic sequencing. The composition of the microbial community and potential pathogens differed significantly in wastewater and river water samples, and the total relative abundance of fecal indicator bacteria was positively correlated with the total relative abundance of potential pathogens (p < 0.001 and Pearson's r = 0.758). Network analysis indicated that partial ARG subtypes such as dfrE, sul2, and PmrE were significantly correlated with indicator bacteria (p < 0.05 and Pearson's r > 0.6). Notably, Klebsiella was the indicator bacteria significantly correlated with 4 potential pathogens and 14 ARG subtypes. ARGs coexisting with mobile gene elements were mainly found in Thauera, Pseudomonas, Escherichia, and Acinetobacter. Next-generation sequencing (NGS) can be used to conduct preliminary surveys of environmental samples to access potential health risks, thereby facilitating water resources management.202235175529
6840140.9995High-throughput profiling and analysis of antibiotic resistance genes in East Tiaoxi River, China. The rapid human activities and urbanization exacerbate the human health risks induced by antibiotic resistance genes (ARGs). In this study, the profiling of ARGs was investigated using high-throughput qPCR from water samples of 13 catchment areas in East Tiaoxi River, China. High prevalence of ARGs indicated significant antibiotic resistance pollution in the research area (absolute abundance: 6.1 × 10(8)-2.1 × 10(10) copies/L; relative abundance: 0.033-0.158 copies/cell). Conventional water qualities (COD, TN, TP, NH(3)-N), bacterial communities and mobile gene elements (MGEs) were detected and analyzed as factors of ARGs shift. Nutrient and MGEs showed positive correlation with most ARGs (P < 0.05) and bacteria community was identified as the key contributing factor driving ARGs alteration. With the land-use study and field investigation, country area, especially arable, was expected as a high spot for ARGs shift and pathogen breeding. Comparing to environmental background, promotion of ARGs and marked shift of bacterial community were observed in country and urban city areas, indicating that human activities may lead to the spread of ARGs. Analysis of factors affecting ARGs in this study may shed new light on the mechanism of the maintenance and propagation of ARGs in urban rivers.201728715769
8024150.9995High Concentrations of Tilmicosin Promote the Spread of Multidrug Resistance Gene tolC in the Pig Gut Microbiome Through Mobile Genetic Elements. The impact of antibiotic therapy on the spread of antibiotic resistance genes (ARGs) and its relationship to gut microbiota remains unclear. This study investigated changes in ARGs, mobile genetic elements (MGEs), and gut microbial composition following tilmicosin administration in pigs. Thirty pigs were randomly divided into control (CK), low-concentration (0.2 g/kg; L), and high-concentration (0.4 g/kg; H) groups. Tilmicosin concentration in manure peaked on day 16 of dosing and dropped below detectable levels by day 13 of the withdrawal period. While tilmicosin did not significantly affect the total abundance of macrolide resistance genes (MRGs) (p > 0.05), it significantly increased the abundance of the multidrug resistance gene tolC in the H group compared with the L and CK groups during the withdrawal period (p < 0.05). This increase was associated with a coincidental rise in the abundance of MGEs (e.g., int1 and int2) and the growth of potential tolC-hosting bacteria such as Paenalcaligenes and Proteiniclasticum. Redundancy analysis showed gut microbial composition as the primary driver of MRG abundance, with MGEs, tilmicosin concentration, and manure physicochemical properties playing secondary roles. These findings suggest that high-dose tilmicosin may alter the gut microbiota and promote ARG spread via MGE-mediated transfer.202439795013
6870160.9995Antibiotic resistome in landfill leachate and impact on groundwater. Landfill leachate is a hotspot in antibiotic resistance development. However, little is known about antibiotic resistome and host pathogens in leachate and their effects on surrounding groundwater. Here, metagenomic sequencing was used to explore profiles, host bacteria, environmental risks and influencing factors of antibiotic resistome in raw and treated leachate and surrounding groundwater of three landfills. Results showed detection of a total of 324 antibiotic resistance genes (ARGs). The ARGs conferring resistance to multidrug (8.8 %-25.7 %), aminoglycoside (13.1 %-39.2 %), sulfonamide (10.0 %-20.9 %), tetracycline (5.7 %-34.4 %) and macrolide-lincosamide-streptogramin (MLS, 5.3 %-29.5 %) were dominant in raw leachate, while multidrug resistance genes were the major ARGs in treated leachate (64.1 %-83.0 %) and groundwater (28.7 %-76.6 %). Source tracking analysis suggests non-negligible influence of leachate on the ARGs in groundwater. The pathogens including Acinetobacter pittii, Pseudomonas stutzeri and P. alcaligenes were the major ARG-carrying hosts. Variance partitioning analysis indicates that the microbial community, abiotic variables and their interaction contributed most to the antibiotic resistance development. Our results shed light on the dissemination and driving mechanisms of ARGs from leachate to the groundwater, indicating that a comprehensive risk assessment and efficient treatment approaches are needed to deal with ARGs in landfill leachate and nearby groundwater. ENVIRONMENTAL IMPLICATIONS: Antibiotic resistance genes are found abundant in the landfill sites, and these genes could be disseminated into groundwater via leaching of wastewater and infiltration of leachate. This results in deterioration of groundwater quality and human health risks posed by these ARGs and related pathogens. Thus measures should be taken to minimize potential negative impacts of landfills on the surrounding environment.202438547976
7151170.9995Pollution profiles of antibiotic resistance genes associated with airborne opportunistic pathogens from typical area, Pearl River Estuary and their exposure risk to human. To reveal the selective pressures of near-shore human activities on marine and continental bioaerosols, the pollution profile and potential exposure risk of airborne pathogens and antibiotic-resistance genes (ARGs) in Pearl River Estuaries (113.52 (o)E, 22.69 (o)N), a transitional zone between marine and continental environments, were fully explored. The results showed that the total bacteria among bioaerosols varied largely with average pollution levels of 1.86 × 10(5) and 4.35 × 10(4) cfu m(-3) in spring and summer, respectively, and were high than those of airborne fungi. The predominant aerodynamic diameters of bioaerosols were in respirable size range (<4.7 µm), and the microbes communities' diversity and abundance varied significantly. Besides, many opportunistic pathogenic bacteria (Burkholderia-Paraburkholderia, Staphylococcus and Acinetobacter) and fungi (Alternaria, Penicillium and Cladosporium) were dominant in bioaerosol samples. Of 21 ARGs subtypes detected, the tetracycline resistance gene tetA was the most abundant, followed by aminoglycoside resistance gene and mobile genetic elements. Correlation analysis revealed that the changes of pathogens community contributed significantly to the prevalence of ARGs in bioaerosol. Based on the average daily dose rates of microorganisms and human direct intake of ARGs, health risk of bioaerosols from the Pearl River Estuaries were also evaluated. In summary, the presence of opportunistic pathogens and diversity of ARGs strengthens the call to consider the bioaerosol in air quality monitoring and risk assessment in the future.202032645489
3501180.9995Microbial community and antibiotic resistance gene distribution in food waste, anaerobic digestate, and paddy soil. The study assessed the occurrence and distribution of microbial community and antibiotic resistance genes (ARGs) in food waste, anaerobic digestate, and paddy soil samples, and revealed the potential hosts of ARGs and factors influencing their distribution. A total of 24 bacterial phyla were identified, of which 16 were shared by all samples, with Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria accounting for 65.9-92.3 % of the total bacterial community. Firmicutes was the most abundant bacteria in food waste and digestate samples, accounting for 33-83 % of the total microbial community. However, in paddy soil samples with digestate, Proteobacteria had the highest relative abundance of 38-60 %. Further, 22 ARGs were detected in food waste and digestate samples, with multidrug, macrolide-lincosamide-streptogramin (MLS), bacitracin, aminoglycoside, tetracycline, vancomycin, sulfonamide, and rifamycin resistance genes being the most abundant and shared by all samples. The highest total relative abundance of ARGs in food waste, digestate, and soil without and with digestate was detected in samples from January 2020, May 2020, October 2019, and May 2020, respectively. The MLS, vancomycin, tetracycline, aminoglycoside, and sulfonamide resistance genes had higher relative abundance in food waste and anaerobic digestate samples, whereas multidrug, bacteriocin, quinolone, and rifampin resistance genes were more abundant in paddy soil samples. Redundancy analysis demonstrated that aminoglycoside, tetracycline, sulfonamide, and rifamycin resistance genes were positively correlated with total ammonia nitrogen and pH of food waste and digestate samples. Vancomycin, multidrug, bacitracin, and fosmidomycin resistance genes had positive correlations with potassium, moisture, and organic matter in soil samples. The co-occurrence of ARG subtypes with bacterial genera was investigated using network analysis. Actinobacteria, Proteobacteria, Bacteroidetes, and Acidobacteria were identified as potential hosts of multidrug resistance genes.202337196953
3216190.9995Effects 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