Antimicrobial resistance transmission in the environmental settings through traditional and UV-enabled advanced wastewater treatment plants: a metagenomic insight. - Related Documents




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726701.0000Antimicrobial resistance transmission in the environmental settings through traditional and UV-enabled advanced wastewater treatment plants: a metagenomic insight. BACKGROUND: Municipal wastewater treatment plants (WWTPs) are pivotal reservoirs for antibiotic-resistance genes (ARGs) and antibiotic-resistant bacteria (ARB). Selective pressures from antibiotic residues, co-selection by heavy metals, and conducive environments sustain ARGs, fostering the emergence of ARB. While advancements in WWTP technology have enhanced the removal of inorganic and organic pollutants, assessing ARG and ARB content in treated water remains a gap. This metagenomic study meticulously examines the filtration efficiency of two distinct WWTPs-conventional (WWTPC) and advanced (WWTPA), operating on the same influent characteristics and located at Aligarh, India. RESULTS: The dominance of Proteobacteria or Pseudomonadota, characterized the samples from both WWTPs and carried most ARGs. Acinetobacter johnsonii, a prevailing species, exhibited a diminishing trend with wastewater treatment, yet its persistence and association with antibiotic resistance underscore its adaptive resilience. The total ARG count was reduced in effluents, from 58 ARGs, representing 14 distinct classes of antibiotics in the influent to 46 and 21 in the effluents of WWTPC and WWTPA respectively. However, an overall surge in abundance, particularly influenced by genes such as qacL, bla(OXA-900), and rsmA was observed. Numerous clinically significant ARGs, including those against aminoglycosides (AAC(6')-Ib9, APH(3'')-Ib, APH(6)-Id), macrolides (EreD, mphE, mphF, mphG, mphN, msrE), lincosamide (lnuG), sulfonamides (sul1, sul2), and beta-lactamases (bla(NDM-1)), persisted across both conventional and advanced treatment processes. The prevalence of mobile genetic elements and virulence factors in the effluents possess a high risk for ARG dissemination. CONCLUSIONS: Advanced technologies are essential for effective ARG and ARB removal. A multidisciplinary approach focused on investigating the intricate association between ARGs, microbiome dynamics, MGEs, and VFs is required to identify robust indicators for filtration efficacy, contributing to optimized WWTP operations and combating ARG proliferation across sectors.202540050994
685810.9996Antibiotic resistance genes risks in relation to host pathogenicity and mobility in a typical hospital wastewater treatment process. Hospital wastewaters (HWWs) serve as critical reservoirs for disseminating antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB). However, the dynamics and noteworthy shifts of ARGs and their associated pathogenicity, mobility, and resistome risks during HWWs treatment processes remain poorly understood. Utilizing metagenomic sequencing and assembly, we identified 817 ARG subtypes conferring resistance to 20 classes of antibiotics across 18 HWW samples from influent to effluent. Genes encoding resistance to multidrug, aminoglycoside and beta_lactam were the most prevalent ARG types, reflecting patterns observed in clinical settings. On-site treatment efforts decreased the relative abundance of ARGs by 77.4% from influent to secondary sedimentation, whereas chlorine disinfection significantly increased their abundance in the final effluent. Deterministic processes primarily drove the taxonomic assembly, with Proteobacteria being the most abundant phylum and serving as the primary host for 15 ARG types. Contig-based analysis further revealed 114 pathogenic ARB, with Escherichia coli, Pseudomonas alcaligenes, and Pseudomonas aeruginosa exhibiting multidrug-resistant. The contributions of host bacteria and pathogenic ARB varied throughout wastewater treatment. In addition, 7.10%-31.0 % ARGs were flanked by mobile genetic elements (MGEs), predominantly mediated by transposase (74.1%). Notably, tnpA exhibited the highest potential for ARG dissemination, frequently co-occurring with beta-lactam resistance genes (35.2%). Considering ARG profiles, pathogenic hosts, and transferability, raw influent exhibited the highest antibiotic resistome risk index (ARRI), followed by the final effluent. Chlorine disinfection exacerbated resistome risks by inducing potential pathogenic ARB and mobile ARGs, posing threats to the receiving environment. This study delineates ARG occurrence patterns, highlights mechanisms of ARG carriage and horizontal gene transfer, and provides insights for assessing resistance risks and prioritizing interventions in clinical settings.202438964571
733320.9996Metagenomics 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
686130.9996Investigating the antibiotic resistance genes and mobile genetic elements in water systems impacted with anthropogenic pollutants. A wide range of pollutants, including heavy metals, endocrine-disrupting chemicals (EDCs), residual pesticides, and pharmaceuticals, are present in various water systems, many of which strongly drive the proliferation and dissemination of antimicrobial resistance genes (ARGs), heightening the antimicrobial resistance (AMR) crisis and creating a critical challenge for environmental and health management worldwide. This study addresses the impact of anthropogenic pollutants on AMR through an extensive analysis of ARGs and mobile genetic elements (MGEs) in urban wastewater, source water, and drinking water supplies in India. Results indicated that bla(TEM) and bla(CTXM-32) were the dominant ARGs across all water systems, underscoring the prevalence and dominance of resistance against β-lactam antibiotics. Moreover, transposase genes such as tnpA-02, tnp-04, and tnpA-05 were detected across all water systems, indicating potential mechanisms for genetic transfer. The ubiquitous presence of intI-1 and clin-intI-1 genes underscores the widespread dissemination of MGEs, posing challenges for water quality management. Besides, human pathogenic bacteria such as Clostridium, Acinetobacter, and Legionella were also detected, highlighting potential health risks associated with contaminated water. The identified pathogenic bacterial genera belong to the phyla Pseudomonadota and Firmicutes. Leveraging linear regression to analyze correlations between EDCs and ARG-MGEs provides deeper insights into their interconnected dynamics. DMP showed a significant influence on tnpA-02 (p = 0.005), tnpA-07 (p = 0.015), sul-1 (p = 0.008), intI-1 (p = 0.03), and clin-intI1 (p = 0.012), while DiNOP demonstrated a very high impact on tnpA-05 (p = 0). Redundancy analysis revealed significant correlations between resistance genes and EDCs. Additionally, environmental parameters such as pH were highly correlated with the majority of MGEs and bla(CTXM-32). Furthermore, we found that F(-), NO(-3), and SO(4)(-2) were significantly correlated with sul-1, with F(-) exhibiting the highest impact, emphasizing the intricate interplay of pollutants in driving AMR. Understanding these interconnected factors is crucial for developing effective strategies and sustainable solutions to combat antibiotic resistance in environmental settings.202539824274
687040.9995Antibiotic 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
732950.9995Metagenomic analysis reveals the abundance changes of bacterial communities and antibiotic resistance genes in the influent and effluent of hospital wastewater. The presence of substantial quantities of antibiotics and their metabolites in hospital wastewater can lead to the accumulation of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs). Research on the influent and effluent sewage of hospitals is crucial for understanding the effectiveness of wastewater treatment systems in inactivating ARB and ARGs. Key features of microbial communities and ARGs in influent and effluent wastewater - including taxonomic diversity and relative abundance - were assessed via metagenomic sequencing. The treatment process resulted in a reduction of the overall bacterial count in hospital wastewater. However, a notable increase in relative abundance was observed for three phyla, 16 genera, and 21 species post-treatment. Bacteria harboring ARGs were predominantly identified as belonging to Pseudomonadota and Bacillota. A total of 354 ARGs were detected in the influent, while 331 were identified in the effluent samples, with a general decrease in absolute abundance. Nevertheless, the relative abundance of certain ARGs, such as mphG, fosA8, and soxR, was found to increase in the effluent across all samples. Seasonal fluctuations also played a role in the distribution of microbial communities and ARGs. These findings underscore the role of hospital wastewater treatment systems in reducing the discharge of ARB and ARGs into the environment, while also revealing potential shortcomings in the wastewater treatment process that necessitate further improvement for more effective removal of these ARGs.202541171744
317760.9995Metagenomic investigation of antibiotic resistance genes and resistant bacteria contamination in pharmaceutical plant sites in China. Pharmaceutical plant sites play a significant role in the dissemination of antibiotic resistance genes (ARGs) into the environment. It is imperative to comprehensively monitor of ARGs across various environmental media at these sites. This study focused on three pharmaceutical plants, two located in North China and one in South China. Through metagenomic approaches, we examined the composition, mobility potential, and bacterial hosts of ARGs in diverse media such as process water, groundwater, topsoil, soil cores, and pharmaceutical fermentation residues across diverse environmental matrices, including topsoil, soil cores, process water, groundwater, and pharmaceutical fermentation residues. We identified a wide array of ARGs, comprising 21 types and 740 subtypes, with process water exhibiting the highest abundance and diversity. Treatment processes varied in their efficacy in eliminating ARGs, and the clinically relevant ARGs should also be considered when evaluating wastewater treatment plant efficiency. Geographical distinctions in groundwater ARG distribution between northern and southern regions were observed. Soil samples from the three sites showed minimal impact from pharmaceutical activity, with vancomycin-resistance genes being the most prevalent. High levels of ARGs in pharmaceutical fermentation residues underscore the necessity for improved waste management practices. Metagenomic assembly revealed that plasmid-mediated ARGs were more abundant than chromosome-mediated ARGs. Metagenome-assembled genomes (MAGs) analysis identified 166 MAGs, with 62 harboring multiple ARGs. Certain bacteria tended to carry specific types of ARGs, revealing distinct host-resistance associations. This study enhances our understanding of ARG dissemination across different environmental media within pharmaceutical plants and underscores the importance of implementing strict regulations for effluent and residue discharge to control ARG spread.202438960118
733270.9995Metagenomic Survey Reveals More Diverse and Abundant Antibiotic Resistance Genes in Municipal Wastewater Than Hospital Wastewater. Alongside antibiotic resistance, co-selection of antibiotics, biocides, and metal resistance is a growing concern. While hospital wastewater is considered a hotspot for antibiotic-resistant bacteria (ARB) and genes (ARGs), the scenario in India, one of the biggest consumers of antibiotics, remains poorly described. In this study, we used metagenomic sequencing to characterize ARGs and biocide/metal resistance genes (BMRGs) in four wastewater treatment plants (WWTPs) in Jaipur City of India. We observed a significantly lower richness and abundance of ARGs in the influent of a WWTP exclusively receiving hospital wastewater when compared to other three WWTPs involving municipal wastewater treatment. Several tetracycline and macrolide-lincosamide-streptogramin resistance genes were enriched in influents of these three municipal wastewater-related treatment plants, whereas hospital wastewater had a higher abundance of genes conferring resistance to disinfectant-related compounds such as synergize and wex-cide-128, reflecting the patterns of antibiotic/disinfectant use. Of note, in the wastewater system with more chemicals, there was a strong correlation between the numbers of ARGs and BMRGs potentially harbored by common hosts. Our study highlights significant influxes of ARGs from non-hospital sources in Jaipur City, and thus more attention should be paid on the emergence of ARGs in general communities.202134526976
309780.9995Investigation 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
686090.9995Impact of coastal deoxygenation on antibiotic resistance gene profiles in size-fractionated bacterial communities. Oxygen loss disrupts marine ecosystems, threatening biodiversity and causing mass mortality of marine life. Antibiotic resistance genes (ARGs) pose a significant threat to human health by promoting the spread of resistant pathogens, making infections harder to treat and increasing mortality risks. However, the interplay between deoxygenation and ARG dynamics remains poorly understood. In this study, we employed time-series metagenomics to investigate the responses of ARG profiles in free-living (FL) and particle-associated (PA) fraction to oxygen loss during a 22-day summer deoxygenation event in the East China Sea. In total, we identified 1,186 ARG subtypes and 2,279 mobile genetic element (MGE) subtypes. The most dominant resistance classes of antibiotics were multidrug (23.5%), followed by tetracycline (15%), macrolide-lincosamide-streptogramin (13.4%), peptide (10.3%), glycopeptide (8.7%), aminoglycoside (7.3%), and beta-lactam (4.9%). We found that ARG richness in FL fraction increased with declining oxygen levels, particularly for beta-lactam and multidrug class, while no significant relationship was observed in the PA fraction. Although the total relative abundance of ARGs in both fraction showed no significant oxygen dependence, beta-lactam and multidrug resistance genes in FL fraction significantly increased with oxygen loss. Co-occurrence network analysis revealed stronger positive associations between ARGs and MGEs in the FL fraction, suggesting enhanced gene transfer among environmental bacteria. Furthermore, neutral community model analysis indicated that stochastic processes also played an interactive role in shaping ARG composition dynamics in both bacterial fractions. Our findings provide evidence that coastal deoxygenation preferentially enriches high-risk ARGs (e.g., beta-lactamase genes) in FL bacteria through MGE-mediated transfer, highlighting escalating antibiotic resistance risks that threaten both ecosystem and human health under climate warming. This study offers a framework for size-fractionated ARG monitoring and targeted mitigation strategies in coastal ecosystems.202540669246
7233100.9995Distribution, sources, and potential risks of antibiotic resistance genes in wastewater treatment plant: A review. Irrational use of antibiotics produces a large number of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs). Wastewater treatment plants (WWTPs) act as important sources and sinks of ARGs, and play an important role in their generation, treatment, and dissemination. This study summarizes the types, concentrations, and factors of ARGs in WWTPs, investigates the sources of ARGs in wastewater, compares the removal efficiencies of different treatment processes on ARGs, and analyzes the potential risks of ARGs accumulation in effluent, sludge and their emission into the air. The results show that the main ARGs detected in the influent of WWTPs are the genes resistant to macrolides (ermB, ermF), tetracyclines (tetW, tetA, tetC), sulfonamides (sul1, sul2), and β-lactams (bla(OXA), bla(TEM)). The concentrations of ARGs in the influent of the WWTPs are 2.23 × 10(2)-3.90 × 10(9) copies/mL. Wastewater quality and microbial community are the dominant factors that affect the distribution characteristics of ARGs. The accumulation of ARGs in effluent, sludge, and aerosols pose potential risks to the regional ecological environment and human health. Based on these results, research trends with respect to ARGs in WWTPs are also prospected.202235921944
6859110.9995Exploring the antibiotic resistome in activated sludge and anaerobic digestion sludge in an urban wastewater treatment plant via metagenomic analysis. Antibiotic resistance genes (ARGs) are emerging contaminants that pose a potential threat to human health worldwide. Urban wastewater treatment plants (WWTPs) are a main source of both antibiotic-resistant bacteria and ARGs released into the environment. Nevertheless, the propagation of ARGs and their underlying mechanisms and the dynamics of mobile genetic elements (MGEs) in WWTPs have rarely been investigated in South Korea. In this study, shotgun metagenomic analysis was used to identify comprehensive ARGs and their mechanisms, bacterial communities, and MGEs from 4 configurations with 2 activated sludge (AS) and 2 anaerobic digestion sludge (ADS) samples. A total of 181 ARG subtypes belonging to 22 ARG types were broadly detected, and the ARG abundances in the AS samples were 1.3-2.0 orders of magnitude higher than in the ADS samples. Multidrug and bacitracin resistance genes were the predominant ARG types in AS samples, followed by ARGs against sulfonamide, tetracycline, and β-lactam. However, the composition of ARG types in ADS samples was significantly changed. The abundance of multidrug and β-lactam resistance genes was drastically reduced in the ADS samples. The resistance genes of MLS were the predominant, followed by ARGs against sulfonamide and tetracycline in the ADS samples. In addition, plasmids were the dominant MGEs in the AS samples, while integrons (intI1) were the dominant MGEs in the ADS samples. These results provide valuable information regarding the prevalence of ARG types and MGEs and the difference patterns between the AS and ADS systems.202031875929
7140120.9995Metagenomic insight into the prevalence and driving forces of antibiotic resistance genes in the whole process of three full-scale wastewater treatment plants. The spread of antibiotic resistance genes (ARGs) is an emerging global health concern, and wastewater treatment plants (WWTPs), as an essential carrier for the occurrence and transmission of ARGs, deserves more attention. Based on the Illumina NovaSeq high-throughput sequencing platform, this study conducted a metagenomic analysis of 18 samples from three full-scale WWTPs to explore the fate of ARGs in the whole process (influent, biochemical treatment, advanced treatment, and effluent) of wastewater treatment. Total 70 ARG subtypes were detected, among which multidrug, aminoglycoside, tetracycline, and macrolide ARGs were most abundant. The different treatment processes used for three WWTPs were capable of reducing ARG diversity, but did not significantly reduce ARG abundance. Compared to that by denitrification filters, the membrane bioreactor (MBR) process was advantageous in controlling the prevalence of multidrug ARGs in WWTPs. Linear discriminant analysis Effect Size (LEfSe) suggested g_Nitrospira, g_Curvibacter, and g_Mycobacterium as the key bacteria responsible for differential ARG prevalence among different WWTPs. Meanwhile, adeF, sul1, and mtrA were the persistent antibiotic resistance genes (PARGs) and played dominant roles in the prevalence of ARGs. Proteobacteria and Actinobacteria were the host bacteria of majority ARGs in WWTPs, while Pseudomonas and Nitrospira were the most crucial host bacteria influencing the dissemination of critical ARGs (e.g., adeF). In addition, microbial richness was determined to be the decisive factor affecting the diversity and abundance of ARGs in wastewater treatment processes. Overall, regulating the abundance of microorganisms and key host bacteria by selecting processes with microbial interception, such as MBR process, may be beneficial to control the prevalence of ARGs in WWTPs.202337356328
7330130.9995Deterministic assembly process dominates bacterial antibiotic resistome in wastewater effluents receiving river. Antibiotic resistance has become a concerning global health challenge, such as the dissemination of bacteria and genes between humans and the environments. Wastewater treatment plants (WWTPs) effluents, as significant reservoirs for antimicrobial resistant bacteria and antibiotic resistance genes (ARGs), pose critical risks to public health. However, whether wastewater effluent prominently contributes to the abundance of ARGs and their community assembly processes in receiving river has yet been unclear. Here we investigated the effects of the effluent discharge on the ARGs and their associate microbial community in the receiving river (Qinhuai River, Nanjing) of upstream and 2000 m downstream of one WWTPs discharge point. Results revealed that the total antibiotic concentrations of all sediment samples ranged from 37.86 to 76.11 µg/kg dw, while antibiotic concentrations and ARG abundances in the river near the wastewater discharge site were significantly higher than that of the downstream receiving river. The metagenomic assembly obtained 245 ARGs associated with 19 antibiotic types in the receiving river. Network analyses confirmed that Proteobacteria, Firmicutes, Acidobacteria, and Bacteroides were the key phylum and positively correlated with the antibiotic resistome. Additionally, the bacterial pathogens of the receiving river were identified as the most frequent strains of clinically relevant antibacterial resistance, such as Streptococcus pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. Using null modeling analysis to determine the quantification of ecological processes, the results showed that heterogeneous environmental selection (81.81%) was a dominate role of the ecological mechanisms determining the ARG community reconstruction in the receiving river. Our results may contribute to control the environmental dissemination of antimicrobial resistance risks in aquatic environments.202235864403
7218140.9995Mass-immigration shapes the antibiotic resistome of wastewater treatment plants. Wastewater treatment plants (WWTPs) are the hotspots for the spread of antibiotic resistance genes (ARGs) into the environment. Nevertheless, a comprehensive assessment of the city-level and short-term daily (inter-day) variations of ARG profiles in the whole process (influent-INF, activated sludge-AS and effluent-EF) of WWTPs is still lacking. Here, 285 ARGs and ten mobile gene elements were monitored in seven WWTPs in Xiamen for seven days via high-throughput qPCR. The average daily load of ARGs to WWTPs was about 1.32 × 10(20) copies/d, and a total of 1.56 × 10(18) copies/d was discharged to the environment across the entire city. Stochastic processes were the main force determining the assembly of ARG communities during sampling campaign, with their relative importance ranked in the order of INF > EFF > AS. There're little daily variations in ARG richness, abundance, β-diversity composition as well as assembly mechanisms. The results of SourceTracker, variation partitioning analysis, and hierarchical partitioning analysis indicated that bacteria and ARGs from upstream treatment processes played an increasingly dominant role in shaping ARG communities in AS and EFF, respectively, suggesting the importance of mass-immigration of bacteria and ARGs from the source on ARG transport in wastewater treatment processes. This emphasizes the need to revise the way we mitigate ARG contamination but focus on the source of ARGs in urban wastewater.202437914134
3189150.9995Hospital 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
3197160.9995Antibiotic 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
6869170.9995Contaminant-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
3179180.9995Deciphering the mobility, pathogenic hosts, and co-selection of antibiotic resistance genes in untreated wastewater from three different hospitals. OBJECTIVE: Antibiotic resistance genes (ARGs) in hospital wastewater pose significant environmental and public health risks, yet the co-selection mechanisms involving metal/biocide resistance genes (MRGs/BRGs) and the role of mobile genetic elements (MGEs) remain poorly characterized. This study aimed to comprehensively assess the abundance, mobility, pathogenic hosts, and co-selection patterns of ARGs, MRGs, and BRGs in untreated wastewater from three types of hospitals. METHODS: Untreated wastewater samples from nine sources across three hospital types (general, traditional Chinese medicine, and dental) were analyzed using metagenomic sequencing and assembly. ARGs, MRGs, and BRGs were identified via the SARG and BacMet databases. ARG hosts, mobility, and MGE co-occurrence were analyzed using PlasFlow and MOB-suite, with risk levels evaluated alongside pathogenic bacteria databases. RESULTS: A total of 1911 ARGs (222 subtypes), 1662 MRGs (167 subtypes), and 916 BRGs (139 subtypes) were detected. Tetracycline, multidrug, and β-lactam resistance genes were predominant, with 46.43 % of ARGs being plasmid-associated. Key pathogens including Klebsiella pneumoniae and Enterococcus spp. harbored high-risk ARGs such as KPC-2 and NDM-1. Notably, 76.2 % of ARGs in traditional Chinese medicine hospital wastewater were classified as high-risk. Significant co-occurrence of ARGs with MGEs (e.g., DDE recombinases) and MRGs/BRGs was observed, underscoring the role of horizontal gene transfer and co-selection. CONCLUSION: Untreated hospital wastewater represents a significant reservoir of ARGs, with risks exacerbated by pathogenic hosts, MGE-mediated HGT, and metal/biocide co-selection. These findings underscore the urgent need for optimized wastewater treatment strategies to curb the spread of antibiotic resistance and inform future intervention efforts.202541067299
7327190.9995Exploring the microbiome, antibiotic resistance genes, mobile genetic element, and potential resistant pathogens in municipal wastewater treatment plants in Brazil. Wastewater treatment plants (WWTPs) have been widely investigated in Europe, Asia and North America regarding the occurrence and fate of antibiotic resistance (AR) elements, such as antibiotic resistance genes (ARGs), mobile genetic elements (MGEs) and antibiotic resistant bacteria and pathogens. However, monitoring data about AR elements in municipal WWTPs in Brazil are scarce. This study investigated the abundance of intI1, five ARGs (sul1, tetA, blaTEM, ermB and qnrB) and 16S rRNA in raw and treated wastewater of three WWTPs, using different sewage treatments named CAS (Conventional activated sludge), UASB/BTF (UASB followed by biological trickling filter) and MAS/UV (modified activated sludge with UV disinfection stage). Bacterial diversity and the presence of potentially pathogenic groups were also evaluated, and associations between genetic markers and the bacterial populations were presented. All WWTPs decreased the loads of genetic markers finally discharged to receiving water bodies and showed no evidence of being hotspots for antimicrobial resistance amplification in wastewater, since the abundances of intI1 and ARGs within the bacterial population were not increased in the treated effluents. UASB/BTF showed a similar performance to that of the CAS and MAS/UV, reinforcing the sanitary and environmental advantages of this biological treatment, widely applied for wastewater treatment in warm climate regions. Bacterial diversity and richness increased after treatments, and bacterial communities in wastewater samples differed due to catchment areas and treatment typologies. Potential pathogenic population underwent considerable decrease after the treatments; however, strong significant correlations with intI1 and ARGs revealed potential multidrug-resistant pathogenic bacteria (Aeromonas, Arcobacter, Enterobacter, Escherichia-Shigella, Stenotrophomonas and Streptococcus) in the treated effluents, although in reduced relative abundances. These are contributive results for understanding the fate of ARGs, MGEs and potential pathogenic bacteria after wastewater treatments, which might support actions to mitigate their release into Brazilian aquatic environments in the near future.202235724791