Hospital Wastewater as a Reservoir for Antibiotic Resistance Genes: A Meta-Analysis. - Related Documents




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318901.0000Hospital Wastewater as a Reservoir for Antibiotic Resistance Genes: A Meta-Analysis. Background: The emergence and dissemination of antibiotic resistance genes (ARGs) in the environment poses a huge global health hazard. Hospital wastewater (HWW), in which a high density of antibiotic residues and antibiotic-resistant bacteria are present, may be a reservoir of ARGs dissemination into the environment. Our meta-analysis comprehensively analyzes the prevalence of ARGs in HWW, as well as the influencing factors in ARGs distribution. Methods: Online databases were used to search for literature using the subject terms: "Drug Resistance" AND "Genes" AND "Hospitals" AND "Wastewater." Two reviewers independently applied predefined criteria to assess the literature and extract data including "relative abundance of ARGs," "title," "authors," "country," "location," "sampling year," and "sampling seasons." The median values and 95% confidence intervals of ARGs abundance were calculated by Wilcox.test function in R. Temporal trends, spatial differences, seasonal variations and removal efficiency of ARGs were analyzed by Pearson correlation analysis and Kruskal-Wallis H test. Results: Resistance genes to carbapenems, sulfonamides, tetracyclines and mobile genetic elements were found at high relative abundance (>10(-4) gene copies/16S rRNA gene copies) in HWW. The abundance of resistance genes to extended-spectrum β-lactams, carbapenems, sulfonamides and glycopeptide significantly decreased, while tetracycline resistance genes abundance increased from 2014 to 2018. The abundance of ARGs was significantly different by country but not by season. ARGs could not be completely removed by on-site HWW treatments and the removal efficiency varies for different ARGs. Conclusions: HWW presents more types of ARGs, and their abundance is higher than those in most wastewater systems. HWW may be a reservoir of ARGs and play an important role in the dissemination of ARGs.202033194975
318810.9999Impact of COVID-19 pandemic on profiles of antibiotic-resistant genes and bacteria in hospital wastewater. The COVID-19 pandemic has severely affected healthcare worldwide and has led to the excessive use of disinfectants and antimicrobial agents. However, the impact of excessive disinfection measures and specific medication prescriptions on the development and dissemination of bacterial drug resistance during the pandemic remains unclear. This study investigated the influence of the pandemic on the composition of antibiotics, antibiotic resistance genes (ARGs), and pathogenic communities in hospital wastewater using ultra-performance liquid chromatography-tandem mass spectrometry and metagenome sequencing. The overall level of antibiotics decreased after the COVID-19 outbreak, whereas the abundance of various ARGs increased in hospital wastewater. After COVID-19 outbreak, bla(OXA), sul2, tetX, and qnrS had higher concentrations in winter than in summer. Seasonal factors and the COVID-19 pandemic have affected the microbial structure in wastewater, especially of Klebsiella, Escherichia, Aeromonas, and Acinetobacter. Further analysis revealed the co-existence of qnrS, bla(NDM), and bla(KPC) during the pandemic. Various ARGs significantly correlated with mobile genetic elements, implying their potential mobility. A network analysis revealed that many pathogenic bacteria (Klebsiella, Escherichia, and Vibrio) were correlated with ARGs, indicating the existence of multi-drug resistant pathogens. Although the calculated resistome risk score did not change significantly, our results suggest that the COVID-19 pandemic shifted the composition of residual antibiotics and ARGs in hospital wastewater and contributed to the dissemination of bacterial drug resistance.202337399936
318720.9999Metagenomic Analysis of Antibiotic Resistance Genes in Untreated Wastewater From Three Different Hospitals. Controlling antibiotic resistance genes (ARGs) is a worldwide intervention to ensure global health. Hospital wastewater is the main pollution source of antibiotic-resistant bacteria and ARGs in the environment. Expanding our knowledge on the bacterial composition of hospital wastewater could help us to control infections in hospitals and decrease pathogen release into the environment. In this study, a high-throughput sequencing-based metagenomic approach was applied to investigate the community composition of bacteria and ARGs in untreated wastewater from three different types of hospitals [the general hospital, traditional Chinese medicine (TCM) hospital, and stomatology hospital]. In total, 130 phyla and 2,554 genera were identified from the microbiota of the wastewaters, with significantly different bacterial community compositions among the three hospitals. Total ARG analysis using the Antibiotic Resistance Genes Database (ARDB) and Comprehensive Antibiotic Resistance Database (CARD) revealed that the microbiota in the wastewaters from the three hospitals harbored different types and percentage of ARGs, and their composition was specific to the hospital type based on the correlation analysis between species and ARG abundance, some ARGs contributed to different bacterial genera with various relationships in different hospitals. In summary, our findings demonstrated a widespread occurrence of ARGs and ARG-harboring microbiota in untreated wastewaters of different hospitals, suggesting that protection measures should be applied to prevent human infections. Concurrently, hospital wastewater should be treated more specifically for the removal of pathogens before its discharge into the urban sewage system.202134504480
534930.9999Spread and persistence of antimicrobial resistance genes in wastewater from human and animal sources in São Paulo, Brazil. The spread of antimicrobial resistance (AMR) through multiple reservoirs is a global concern. Wastewater is a critical AMR dissemination source, so this study aimed to assess the persistence of resistance genetic markers in wastewater using a culture-independent approach. Raw and treated wastewater samples (n = 121) from a wastewater treatment plant (WWTP), a human hospital, a veterinary hospital, and a pig farm were monthly collected and concentrated by filtration. DNA was extracted directly from filter membranes, and PCR was used in the qualitative search of 32 antimicrobial resistance genes (ARGs). Selected genes (bla(CTX-M), bla(KPC), qnrB, and mcr-1) were enumerated by quantitative real-time PCR (qPCR). Twenty-six ARGs were detected in the qualitative ARGs search, while quantitative data showed a low variation of the ARG's relative abundance (RA) throughout the months, especially at the human hospital and the WWTP. At the WWTP, despite significantly reducing the absolute number of gene copies/L after each treatment stage (p < 0.05), slight increases (p > 0.05) in the RAs of genes bla(CTX-M), qnrB, and mcr-1 were observed in reused water (tertiary treatment) when compared with secondary effluent. Although the increase is not statistically significant, it is worth noting that there was some level of ARGs concentration after the disinfection process. No significant absolute or relative after-treatment quantification reductions were observed for any ARGs at the veterinary hospital or the pig farm. The spread of ARGs through sewage needs to be continuously addressed, because their release into natural environments may pose potential risks of exposure to resistant bacteria and impact local ecosystems.202438545908
319740.9999Antibiotic resistance and pathogen spreading in a wastewater treatment plant designed for wastewater reuse. Climate change significantly contributes to water scarcity in various regions worldwide. While wastewater reuse is a crucial strategy for mitigating water scarcity, it also carries potential risks for human health due to the presence of pathogenic and antibiotic resistant bacteria (ARB). Antibiotic resistance represents a Public Health concern and, according to the global action plan on antimicrobial resistance, wastewater role in selecting and spreading ARB must be monitored. Our aim was to assess the occurrence of ARB, antibiotic resistance genes (ARGs), and potential pathogenic bacteria throughout a wastewater treatment plant (WWTP) designed for water reuse. Furthermore, we aimed to evaluate potential association between ARB and ARGs with antibiotics and heavy metals. The results obtained revealed the presence of ARB, ARGs and pathogenic bacteria at every stage of the WWTP. Notably, the most prevalent ARB and ARG were sulfamethoxazole-resistant bacteria (up to 7.20 log CFU mL(-1)) and sulII gene (up to 5.91 log gene copies mL(-1)), respectively. The dominant pathogenic bacteria included Arcobacter, Flavobacterium and Aeromonas. Although the abundance of these elements significantly decreased during treatment (influent vs. effluent, p < 0.05), they were still present in the effluent designated for reuse. Additionally, significant correlations were observed between heavy metal concentrations (copper, nickel and selenium) and antibiotic resistance elements (ampicillin-resistant bacteria, tetracycline-resistant bacteria, ARB total abundance and sulII) (p < 0.05). These results underscore the importance of monitoring the role of WWTP in spreading antibiotic resistance, in line with the One Health approach. Additionally, our findings suggest the need of interventions to reduce human health risks associated with the reuse of wastewater for agricultural purposes.202439357555
729350.9998Prevalence and transmission of antibiotic resistance and microbiota between humans and water environments. The transmission routes for antibiotic resistance genes (ARGs) and microbiota between humans and water environments is poorly characterized. Here, we used high-throughput qPCR analyses and 16S rRNA gene sequencing to examine the occurrence and abundance of antibiotic resistance genes and microbiota in both healthy humans and associated water environments from a Chinese village. Humans carried the most diverse assemblage of ARGs, with 234 different ARGs being detected. The total abundance of ARGs in feces, on skin, and in the effluent from domestic sewage treatment systems were approximately 23, 2, and 7 times higher than their abundance in river samples. In total, 53 ARGs and 28 bacteria genera that were present in human feces could also be found in the influent and effluent of rural sewage treatment systems, and also downstream of the effluent release point. We identified the bacterial taxa that showed a significant association with ARGs (P < 0.01, r > 0.8) by network analysis, supporting the idea that these bacteria could carry some ARGs and transfer between humans and the environment. Analysis of ARGs and microbiota in humans and in water environments helps to define the transmission routes and dynamics of antibiotic resistance within these environments. This study highlights human contribution to the load of ARGs into the environment and suggests means to prevent such dissemination.201830420129
321260.9998Distribution and driving factors of antibiotic resistance genes in treated wastewater from different types of livestock farms. Treated wastewater from livestock farms is an important reservoir for antibiotic resistance genes (ARGs), and is a main source of ARGs in the environment. However, the distribution and driving factors of ARGs in treated wastewater from different types of livestock farms are rarely reported. In this study, treated wastewater from 69 large-scale livestock farms of different types, including broiler, layer, and pig farms, was collected, and 11 subtypes of ARGs, 2 mobile genetic elements (MGEs) and bacterial community structure were analyzed. The results revealed detection rates of NDM-1 and mcr-1 of 90 % and 43 %, respectively, and the detection rates of other ARGs were 100 %. The relative abundance of ARGs, such as tetA, tetX and strB, in broiler farms was significantly higher than that in layer farms, but the bacterial α diversity was significantly lower than that in other farm types. Furthermore, although the treatment process had a greater impact on the physicochemical properties of the treated wastewater than the livestock type, livestock type was the main factor affecting the bacterial community in the treated wastewater. The analysis of potential host bacteria of ARGs revealed significant differences in the host bacteria of ARGs in treated wastewater from different types of livestock farms. The host bacteria of ARGs in broiler farms mainly belonged to Actinobacteria, layer farms mainly belonged to Proteobacteria, and pig farms mainly belonged to Firmicutes. Additionally, redundancy analysis showed that the distribution of ARGs may have resulted from the combination of multiple driving factors in different types of livestock farms, among which tnpA and NH(4)(+)-N were the main influencing factors. This study revealed multiple driving factors for the distribution of typical ARGs in treated wastewater from different types of livestock farms, providing basic data for the prevention and control of ARG pollution in agricultural environments.202235934031
733370.9998Metagenomics unveils the role of hospitals and wastewater treatment plants on the environmental burden of antibiotic resistance genes and opportunistic pathogens. Antimicrobial resistance (AMR) is a global health challenge, with hospitals and wastewater treatment plants (WWTPs) serving as significant pathways for the dissemination of antibiotic resistance genes (ARGs). This study investigates the potential of wastewater-based epidemiology (WBE) as an early warning system for assessing the burden of AMR at the population level. In this comprehensive year-long study, effluent was collected weekly from three large hospitals, and treated and untreated wastewater were collected monthly from three associated community WWTPs. Metagenomic analysis revealed a significantly higher relative abundance and diversity of ARGs in hospital wastewater than in WWTPs. Notably, ARGs conferring resistance to clinically significant antibiotics such as β-lactams, aminoglycosides, sulfonamides, and tetracyclines were more prevalent in hospital effluents. Conversely, resistance genes associated with rifampicin and MLS (macrolides-lincosamide-streptogramin) were more commonly detected in the WWTPs, particularly in the treated effluent. Network analysis identified the potential bacterial hosts, which are the key carriers of these ARGs. The study further highlighted the variability in ARG removal efficiencies across the WWTPs, with none achieving complete elimination of ARGs or a significant reduction in bacterial diversity. Additionally, ARG profiles remained relatively consistent in hospital and community wastewater throughout the study, indicating a persistent release of a baseload of ARGs and pathogenic bacteria into surface waters, potentially polluting aquatic environments and entering the food chain. The study underscores the need for routine WBE surveillance, enhanced wastewater treatment strategies, and hospital-level source control measures to mitigate AMR dissemination into the environment.202539798461
309780.9998Investigation of the Prevalence of Antibiotic Resistance Genes According to the Wastewater Treatment Scale Using Metagenomic Analysis. Although extensive efforts have been made to investigate the dynamics of the occurrence and abundance of antibiotic resistance genes (ARGs) in wastewater treatment plants (WWTPs), understanding the acquisition of antibiotic resistance based on the WWTP scale and the potential effects on WWTPs is of relatively less interest. In this study, metagenomic analysis was carried out to investigate whether the WWTP scale could be affected by the prevalence and persistence of ARGs and mobile genetic elements (MGEs). As a result, 152 ARG subtypes were identified in small-scale WWTP samples, while 234 ARG subtypes were identified in large-scale WWTP samples. Among the detectable ARGs, multidrug, MLS (macrolide-lincosamide-streptogramin), sulfonamide, and tetracycline resistance genes had the highest abundance, and large and small WWTPs had similar composition characteristics of ARGs. In MGE analysis, plasmids and integrons were 1.5-2.0-fold more abundant in large-scale WWTPs than in small-scale WWTPs. The profile of bacteria at the phylum level showed that Proteobacteria and Actinobacteria were the most dominant bacteria, representing approximately 70% across large- and small-scale WWTPs. Overall, the results of this study elucidate the different abundances and dissemination of ARGs between large- and small-scale WWTPs, which facilitates the development of next-generation engineered wastewater treatment systems.202133671905
687090.9998Antibiotic 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
7310100.9998Metagenomic Analysis Reveals Changes in Bacterial Communities and Antibiotic Resistance Genes in an Eye Specialty Hospital and a General Hospital Before and After Wastewater Treatment. The spread of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in hospital wastewater poses a great threat to public health, and wastewater treatment plants (WWTPs) play an important role in reducing the levels of ARB and ARGs. In this study, high-throughput metagenomic sequencing was used to analyze the bacterial community composition and ARGs in two hospitals exposed to different antibiotic use conditions (an eye specialty hospital and a general hospital) before and after wastewater treatment. The results showed that there were various potential pathogenic bacteria in the hospital wastewater, and the abundance and diversity of the influent ARGs in the general hospital were higher than those in the eye hospital. The influent of the eye hospital was mainly composed of Thauera and Pseudomonas, and sul1 (sulfonamide) was the most abundant ARG. The influent of the general hospital contained mainly Aeromonas and Acinetobacter, and tet39 (tetracycline) was the most abundant ARG. Furthermore, co-occurrence network analysis showed that the main bacteria carrying ARGs in hospital wastewater varied with hospital type; the same bacteria in wastewater from different hospitals could carry different ARGs, and the same ARG could also be carried by different bacteria. The changes in the bacterial community and ARG abundance in the effluent from the two hospitals showed that the activated sludge treatment and the direct chlorination disinfection can effectively remove some bacteria and ARGs in wastewater but have limitations. The species diversity increased significantly after the activated sludge treatment, while the direct chlorination disinfection did not increase the diversity. The activated sludge treatment has a better effect on the elimination of ARGs than the direct chlorination disinfection. In summary, we investigated the differences in bacterial communities and ARGs in wastewater from two hospitals exposed to different antibiotic usage conditions, evaluated the effects of different wastewater treatment methods on the bacterial communities and ARGs in hospital wastewater, and recommended appropriate methods for certain clinical environments.202235663906
7283110.9998Comparative metagenomics reveals a diverse range of antimicrobial resistance genes in effluents entering a river catchment. The aquatic environment has been implicated as a reservoir for antimicrobial resistance genes (ARGs). In order to identify sources that are contributing to these gene reservoirs, it is crucial to assess effluents that are entering the aquatic environment. Here we describe a metagenomic assessment for two types of effluent entering a river catchment. We investigated the diversity and abundance of resistance genes, mobile genetic elements (MGEs) and pathogenic bacteria. Findings were normalised to a background sample of river source water. Our results show that effluent contributed an array of genes to the river catchment, the most abundant being tetracycline resistance genes tetC and tetW from farm effluents and the sulfonamide resistance gene sul2 from wastewater treatment plant (WWTP) effluents. In nine separate samples taken across 3 years, we found 53 different genes conferring resistance to seven classes of antimicrobial. Compared to the background sample taken up river from effluent entry, the average abundance of genes was three times greater in the farm effluent and two times greater in the WWTP effluent. We conclude that effluents disperse ARGs, MGEs and pathogenic bacteria within a river catchment, thereby contributing to environmental reservoirs of ARGs.201627054725
3098120.9998Bacterial Communities and Resistance and Virulence Genes in Hospital and Community Wastewater: Metagenomic Analysis. Metagenomic studies have made it possible to deepen the analysis of the abundance of bacterial populations that carry resistance and virulence determinants in the wastewater environment. In this study, a longitudinal collection of samples of community and hospital wastewater from August 2021 to September 2022 was obtained. Shotgun metagenomic sequencing and bioinformatic analysis were performed to characterize the bacterial abundance, antimicrobial resistance genes (ARGs), plasmids, and virulence factor genes (VFGs) contained in the wastewater. The microbial composition of the community and hospital wastewater showed that the most abundant bacterial phyla detected in all samples were: Proteobacteria, Bacteroides, Firmicutes, Campylobacterota, and Actinobacteria. Seasonal differences in the relative abundances of species, ARGs, plasmids, and VFGs were observed. In this study, a total of 270 ARGs were detected, and it was found that the absolute abundance of ARGs only showed a 39% reduction in the treated wastewater. Furthermore, the ARGs detected in this study were found to encode resistance to antibiotics of the last choice. Our results showed that plasmids carrying resistance genes were more abundant in raw wastewater, and 60% more abundant in hospital wastewater compared to community wastewater. Several of the VFGs detected in this study encode for adhesion, motility, and biofilm formation, which likely allows bacteria to remain and persist in the wastewater environment and survive WWTP treatment systems, thus managing to escape into the environment via treated wastewater.202540076673
5329130.9998Distribution of Antibiotic Resistance in a Mixed-Use Watershed and the Impact of Wastewater Treatment Plants on Antibiotic Resistance in Surface Water. The aquatic environment has been recognized as a source of antibiotic resistance (AR) that factors into the One Health approach to combat AR. To provide much needed data on AR in the environment, a comprehensive survey of antibiotic-resistant bacteria (ARB), antibiotic resistance genes (ARGs), and antibiotic residues was conducted in a mixed-use watershed and wastewater treatment plants (WWTPs) within the watershed to evaluate these contaminants in surface water. A culture-based approach was used to determine prevalence and diversity of ARB in surface water. Low levels of AR Salmonella (9.6%) and Escherichia coli (6.5%) were detected, while all Enterococcus were resistant to at least one tested antibiotic. Fewer than 20% of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (17.3%) and carbapenem-resistant Enterobacteriaceae (CRE) (7.7%) were recovered. Six ARGs were detected using qPCR, primarily the erythromycin-resistance gene, ermB. Of the 26 antibiotics measured, almost all water samples (98.7%) had detectable levels of antibiotics. Analysis of wastewater samples from three WWTPs showed that WWTPs did not completely remove AR contaminants. ARGs and antibiotics were detected in all the WWTP effluent discharges, indicating that WWTPs are the source of AR contaminants in receiving water. However, no significant difference in ARGs and antibiotics between the upstream and downstream water suggests that there are other sources of AR contamination. The widespread occurrence and abundance of medically important antibiotics, bacteria resistant to antibiotics used for human and veterinary purposes, and the genes associated with resistance to these antibiotics, may potentially pose risks to the local populations exposed to these water sources.202337998788
5351140.9998Bacterial hosts of clinically significant beta-lactamase genes in Croatian wastewaters. Wastewater treatment plants (WWTPs) provide a suitable environment for the interaction of antibiotic resistant bacteria and antibiotic-resistance genes (ARGs) from human, animal, and environmental sources. The aim was to study the influent and effluent of two WWTPs in Croatia to identify bacterial hosts of clinically important beta-lactamase genes (blaTEM, blaVIM, blaOXA-48-like) and observe how their composition changes during the treatment process. A culture-independent epicPCR (Emulsion, Paired isolation and Concatenation Polymerase Chain Reaction) was used to identify the ARG hosts, and 16S rRNA amplicon sequencing to study the entire bacterial community. Different wastewater sources contributed to the significant differences in bacterial composition of the wastewater between the two WWTPs studied. A total of 167 genera were detected by epicPCR, with the Arcobacter genus, in which all ARGs studied were present, dominating in both WWTPs. In addition, the clinically important genera Acinetobacter and Aeromonas contained all ARGs examined. The blaOXA-48-like gene had the highest number of hosts, followed by blaVIM, while blaTEM had the narrowest host range. Based on 16S rRNA gene sequencing, ARG hosts were detected in both abundant and rare taxa. The number of hosts carrying investigated ARGs was reduced by wastewater treatment. EpicPCR provided valuable insights into the bacterial hosts of horizontally transmissible beta-lactamase genes in Croatian wastewater.202438796694
3198150.9998Enhance antibiotic resistance and human health risks in aerosols during the COVID-19 pandemic. Aerosols are an important route for the transmission of antibiotic resistance genes (ARGs). Since the 2019 (COVID-19) pandemic, the large-scale use of disinfectants has effectively prevented the spread of environmental microorganisms, but studies regarding the antibiotic resistance of airborne bacteria remain limited. This study focused on four functional urban areas (commercial areas, educational areas, residential areas and wastewater treatment plant) to study the variations in ARG abundances, bacterial community structures and risks to human health during the COVID-19 pandemic in aerosol. The results indicated the abundance of ARGs during the COVID-19 period were up to approximately 13-fold greater than before the COVID-19 period. Large-scale disinfection resulted in a decrease in total bacterial abundance. However, chlorine-resistant bacteria tended to be survived. Among the four functional areas, the diversity and abundance of aerosol bacteria were highest in commercial aera. Antibiotic susceptibility assays suggested elevated resistance of isolated bacteria to several tested antibiotics due to disinfection exposure. The potential exposure risks of ARGs to human health were 2 times higher than before the COVID-19 pandemic, and respiratory intake was the main exposure route. The results highlighted the elevated antibiotic resistance of bacteria in aerosols that were exposed to disinfectants after the COVID-19 pandemic. This study provides theoretical guidance for the rational use of disinfectants and control of antimicrobial resistance.202336754321
7331160.9998Metagenomics analysis of probable transmission of determinants of antibiotic resistance from wastewater to the environment - A case study. During mechanical-biological treatment, wastewater droplets reach the air with bioaerosols and pose a health threat to wastewater treatment plant (WWTP) employees and nearby residents. Microbiological pollutants and antimicrobial resistance determinants are discharged to water bodies with treated wastewater (TWW), which poses a potential global epidemiological risk. In the present study, the taxonomic composition of microorganisms was analyzed, and the resistome profile and mobility of genes were determined by metagenomic next-generation sequencing in samples of untreated wastewater (UWW), wastewater collected from an activated sludge (AS) bioreactor, TWW, river water collected upstream and downstream from the wastewater discharge point, and in upper respiratory tract swabs collected from WWTP employees. Wastewater and the emitted bioaerosols near WWTP's facilities presumably contributed to the transmission of microorganisms, in particular bacteria of the phylum Actinobacteria and the associated antibiotic resistance genes (ARGs) (including ermB, ant(2″)-I, tetM, penA and cfxA2) to the upper respiratory tract of WWTP employees. The discharged wastewater increased the taxonomic diversity of microorganisms and the concentrations of various ARGs (including bacA, emrE, sul1, sul2 and tetQ) in river water. This study fills in the knowledge gap on the health risks faced by WWTP employees. The study has shown that microbiological pollutants and antimicrobial resistance determinants are also in huge quantities discharged to rivers with TWW, posing a potential global epidemiological threat.202235259375
6869170.9998Contaminant-degrading bacteria are super carriers of antibiotic resistance genes in municipal landfills: A metagenomics-based study. Municipal landfills are hotspot sources of antimicrobial resistance (AMR) and are also important habitats of contaminant-degrading bacteria. However, high diversity of antibiotic resistance genes (ARGs) in landfills hinders assessing AMR risks in the affected environment. More concerned, whether there is co-selection or enrichment of antibiotic-resistant bacteria and contaminant-degrading bacteria in these extremely polluted environments is far less understood. Here, we collected metagenomic datasets of 32 raw leachate and 45 solid waste samples in 22 municipal landfills of China. The antibiotic resistome, antibiotic-resistant bacteria and contaminant-degrading bacteria were explored, and were then compared with other environmental types. Results showed that the antibiotic resistome in landfills contained 1,403 ARG subtypes, with the total abundance over the levels in natural environments and reaching the levels in human feces and sewage. Therein, 49 subtypes were listed as top priority ARGs for future surveillance based on the criteria of enrichment in landfills, mobilizable and present in pathogens. By comparing to those in less contaminated river environments, we elucidated an enrichment of antibiotic-resistant bacteria with contaminant-degrading potentials in landfills. Bacteria in Pseudomonadaceae, Moraxellaceae, Xanthomonadaceae and Enterobacteriaceae deserved the most concerns since 72.2 % of ARG hosts were classified to them. Klebsiella pneumoniae, Acinetobacter nosocomialis and Escherichia coli were abundant multidrug-resistant pathogenic species in raw leachate (∼10.2 % of total microbiomes), but they rarely carried contaminant-degradation genes. Notably, several bacterial genera belonging to Pseudomonadaceae had the most antibiotic-resistant, pathogenic, and contaminant-degrading potentials than other bacteria. Overall, the findings highlight environmental selection for contaminant-degrading antibiotic-resistant pathogens, and provide significant insights into AMR risks in municipal landfills.202539729867
3214180.9998Characteristics of the antibiotic resistance genes in the soil of medical waste disposal sites. The inappropriate disposal of medical waste allows bacteria to acquire antibiotic resistance, which results in a threat to public health. Antibiotic resistance gene (ARG) profiles were determined for 45 different soil samples containing medical waste and 15 nearby soil samples as controls. Besides physical and chemical analyses (i.e., dry matter content, pH value, and metal content), the genomes of microorganisms from the soil samples were extracted for high-throughput sequencing. ARG abundances of these samples were obtained by searching the metagenomic sequences against the antibiotic resistance gene database and the copies of ARGs per copy of the 16S rRNA gene at different levels were assessed. The results showed medical waste accumulation significantly enriched the contents of Cu, Cr, Pb, and As in the tested soil samples. Compared to the controls, the samples collected from areas containing medical waste were significantly enriched (p < 0.05, t-test) with ARGs annotated as sulfonamide and multidrug resistance genes, and in particular, the subtypes sul1 and sul2 (sulfonamide resistance genes), and multidrug_transporter (multidrug resistance gene). Moreover, the ARGs of the samples from the polluted areas were more diverse than those of the control samples (p < 0.05, t-test). The comparatively higher abundance and diversity of ARGs in contaminated soil pose a potential risk to human health.202032402966
7286190.9998Influence of Seasonality and Pollution on the Presence of Antibiotic Resistance Genes and Potentially Pathogenic Bacteria in a Tropical Urban River. BACKGROUND/OBJECTIVES: This study examines how seasonality, pollution, and sample type (water and sediment) influence the presence and distribution of antibiotic resistance genes (ARGs), with a focus on antibiotic resistance genes (ARGs) located on plasmids (the complete set of plasmid-derived sequences, including ARGs) in a tropical urban river. METHODS: Samples were collected from three sites along a pollution gradient in the Virilla River, Costa Rica, during three seasonal campaigns (wet 2021, dry 2022, and wet 2022). ARGs in water and sediment were quantified by qPCR, and metagenomic sequencing was applied to analyze chromosomal and plasmid-associated resistance profiles in sediments. Tobit and linear regression models, along with multivariate ordination, were used to assess spatial and seasonal trends. RESULTS: During the wet season of 2021, the abundance of antibiotic resistance genes (ARGs) such as sul-1, intI-1, and tetA in water samples decreased significantly, likely due to dilution, while intI-1 and tetQ increased in sediments, suggesting particle-bound accumulation. In the wet season 2022, intI-1 remained low in water, qnrS increased, and sediments showed significant increases in tetQ, tetA, and qnrS, along with decreases in sul-1 and sul-2. Metagenomic analysis revealed spatial differences in plasmid-associated ARGs, with the highest abundance at the most polluted site (Site 3). Bacterial taxa also showed spatial differences, with greater plasmidome diversity and a higher representation of potential pathogens in the most contaminated site. CONCLUSIONS: Seasonality and pollution gradients jointly shape ARG dynamics in this tropical river. Plasmid-mediated resistance responds rapidly to environmental change and is enriched at polluted sites, while sediments serve as long-term reservoirs. These findings support the use of plasmid-based monitoring for antimicrobial resistance surveillance in aquatic systems.202540867992