Fate, mobility and pathogenicity of antibiotic resistome in a full-scale drinking water treatment plant: Highlighting the chlorination risks. - Related Documents




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701901.0000Fate, mobility and pathogenicity of antibiotic resistome in a full-scale drinking water treatment plant: Highlighting the chlorination risks. Drinking water treatment plants (DWTPs) serve as the last barrier in preventing the spread of antibiotic resistance genes (ARGs) into tap water, yet the distribution and dissemination mechanisms of ARGs in DWTPs remain unclear. In this study, the antibiotic resistome of a full-scale DWTP using Nansi Lake (an important node of the South-to-North Water Diversion Project's eastern route, China) as water source was investigated based on metagenomic analysis. The results showed that coagulation and chlorination were the two crucial processes increasing the relative abundance of ARGs in the DWTP, and the former predominantly enhanced that of sulfonamide RGs, while the latter increased that of bacitracin, aminoglycoside and multidrug RGs. ARG hosts and mobile genetic elements (MGEs) both played significant roles in ARG compositions. The persistence of Sphingorhabdus during the conventional treatment stages and the dissemination potential of plasmids accounted for the relative abundance of sulfonamide RGs, while the chlorine and multidrug resistance of Acinetobacter, Acidovorax, and Pseudomonas, along with the coexistence of various MGEs, suggested the persistence and transmission risk of ARGs after chlorination. Ozonation and activated carbon filtration could eliminate some human-pathogenic bacteria (HPB), but the chlorination process significantly increased the relative abundance of HPB. The multidrug-resistant HPB such as Acinetobacter calcoaceticus and Acinetobacter haemolyticus were the key targets for risk control in the DWTP. Our findings provide new insights into the fate, mobility, and pathogenicity of ARGs in a typical DWTP, offering beneficial guidance for decision-making in the risk control of ARGs in DWTPs.202540587929
714010.9999Metagenomic 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
701820.9998Shotgun metagenomics assessment of the resistome, mobilome, pathogen dynamics and their ecological control modes in full-scale urban wastewater treatment plants. The conventional activated sludge (CAS) process has limited capacity to remove pathogenic microorganisms and antibiotic resistance genes (ARGs), compared to membrane bioreactors (MBRs). However, the full extent of pathogenic microbial fraction, resistome (antibiotic and biocide resistance genes, ARGs and BRGs) and mobilome (mobile genetic elements, MGE) of urban wastewater treatment plant (UWTP) influents and effluents remains unknown. Thus, the fate of putative pathogenic bacteria, ARGs and potential co-occurrence patterns with BRGs, MGEs and bacterial-predatory microorganisms was determined in two full-scale UWTPs, a MBR and a CAS system, using shotgun metagenomics. Both UWTPs significantly reduced the BOD(5) (99.4-99.9%), COD (97.6-99.4%) and TSS (98.9-99.9%). MBR was more effective in reducing the abundance and diversity of pathogen-containing taxa, with 4 and 30 taxa enriched in MBR and CAS effluents, respectively. MBR treatment favored resistance genes associated with triclosan, whereas CAS effluents contained ARGs associated with antibiotics of clinical importance. Correlations between putative pathogenic bacteria, ARG/BRGs/MGEs and bacterial-predatory microorganisms suggested that: (i) opportunistic pathogens (Clostridia, Nocardia) may acquire ARGs against first-line treatments and (ii) bacteriophages may act as a biogenic mechanism of pathogen removal. These findings reinforce the MBR capacity to retain pathogenic components, hence reducing potential health risks associated with treated wastewater reuse.202134329002
702430.9998Fate of antibiotic resistant E. coli and antibiotic resistance genes during full scale conventional and advanced anaerobic digestion of sewage sludge. Antibiotic resistant bacteria (ARB) and their genes (ARGs) have become recognised as significant emerging environmental pollutants. ARB and ARGs in sewage sludge can be transmitted back to humans via the food chain when sludge is recycled to agricultural land, making sludge treatment key to control the release of ARB and ARGs to the environment. This study investigated the fate of antibiotic resistant Escherichia coli and a large set of antibiotic resistance genes (ARGs) during full scale anaerobic digestion (AD) of sewage sludge at two U.K. wastewater treatment plants and evaluated the impact of thermal hydrolysis (TH) pre-treatment on their abundance and diversity. Absolute abundance of 13 ARGs and the Class I integron gene intI1 was calculated using single gene quantitative (q) PCR. High through-put qPCR analysis was also used to determine the relative abundance of 370 ARGs and mobile genetic elements (MGEs). Results revealed that TH reduced the absolute abundance of all ARGs tested and intI1 by 10-12,000 fold. After subsequent AD, a rebound effect was seen in many ARGs. The fate of ARGs during AD without pre-treatment was variable. Relative abundance of most ARGs and MGEs decreased or fluctuated, with the exception of macrolide resistance genes, which were enriched at both plants, and tetracyline and glycopeptide resistance genes which were enriched in the plant employing TH. Diversity of ARGs and MGEs decreased in both plants during sludge treatment. Principal coordinates analysis revealed that ARGs are clearly distinguished according to treatment step, whereas MGEs in digested sludge cluster according to site. This study provides a comprehensive within-digestor analysis of the fate of ARGs, MGEs and antibiotic resistant E. coli and highlights the effectiveness of AD, particularly when TH is used as a pre-treatment, at reducing the abundance of most ARGs and MGEs in sludgeand preventing their release into the environment.202033259486
701640.9998Metagenomic analysis reveals wastewater treatment plants as hotspots of antibiotic resistance genes and mobile genetic elements. The intensive use of antibiotics results in their continuous release into the environment and the subsequent widespread occurrence of antibiotic resistant bacteria (ARB), antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs). This study used Illumina high-throughput sequencing to investigate the broad-spectrum profiles of both ARGs and MGEs in activated sludge and anaerobically digested sludge from a full-scale wastewater treatment plant. A pipeline for identifying antibiotic resistance determinants was developed that consisted of four categories: gene transfer potential, ARG potential, ARGs pathway and ARGs phylogenetic origin. The metagenomic analysis showed that the activated sludge and the digested sludge exhibited different microbial communities and changes in the types and occurrence of ARGs and MGEs. In total, 42 ARGs subtypes were identified in the activated sludge, while 51 ARG subtypes were detected in the digested sludge. Additionally, MGEs including plasmids, transposons, integrons (intI1) and insertion sequences (e.g. ISSsp4, ISMsa21 and ISMba16) were abundant in the two sludge samples. The co-occurrence pattern between ARGs and microbial taxa revealed by network analysis indicated that some environmental bacteria (e.g. Clostridium and Nitrosomonas) might be potential hosts of multiple ARGs. The findings increase our understanding of WWTPs as hotspots of ARGs and MGEs, and contribute towards preventing their release into the downstream environment.201728689130
702150.9998Metagenomic insights into dissemination of antibiotic resistance across bacterial genera in wastewater treatment. The aim of this study was to evaluate the impacts of conventional wastewater treatment processes including secondary treatment and chlorination on the removal of antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB), and to assess the association of ARGs with their potential hosts in each treatment process. The results showed chlorination with subinhibitory concentration (<8 mg/L) resulted in an increased ARB number in the disinfection effluent. qPCR analysis indicated secondary treatment increased relative abundance of ARGs in remaining bacteria whereas disinfection reduced the relative abundance of those genes effectively. Metagenomic analysis revealed a significant shift of dominating bacterial genera harboring ARGs. Along the treatment train, 48, 95 and 80 genera were identified to be the ARG carriers in primary effluent, secondary effluent, and disinfection effluent, respectively. It was also found that secondary treatment increased the diversity of potential ARG hosts while both secondary treatment and chlorination broadened the host range of some ARGs at the genus level, which may be attributed to the spread of antibiotic resistance across bacterial genera through horizontal transfer. This study highlights the growing concerns that wastewater treatment plants (WWTPs) may disseminate ARGs by associating this effect to specific treatment stages and by correlating ARGs with their bacterial hosts.202133453487
702760.9998Sludge water: a potential pathway for the spread of antibiotic resistance and pathogenic bacteria from hospitals to the environment. Hospitals play an important role in the spread of antibiotic resistance genes (ARGs) and antimicrobial resistance (AMR). The ARGs present in hospital wastewater tend to accumulate in activated sludge, with different ARGs exhibiting varying migration rates. As a result, sludge water produced during the activated sludge treatment process may be a significant source of ARGs entering the environment. Despite this, research into the behavior of ARGs during sludge concentration and dewatering remains limited. This study hypothesizes that ARGs might exhibit new behaviors in sludge water during sludge concentration. Using metagenomic analysis, we explored the distribution and migration risks of ARGs and human pathogenic bacteria (HPB) in sludge water, comparing them with those in hospital wastewater. The findings reveal a strong correlation between ARGs in sludge water and hospital wastewater, with subtypes such as arlR, efpA, and tetR showing higher abundance in sludge water. Although the horizontal gene transfer potential of ARGs is greater in hospital wastewater than in sludge water, the resistance mechanisms and migration pathways are similar even when their HPB host associations differ. ARGs in both environments are primarily transmitted through coexisting mobile genetic elements (MGEs). This suggests that sludge water serves as a critical route for the release of hospital-derived ARGs into the environment, posing potential threats to public health and ecological safety.202540012781
703270.9998Free Radicals on Aging Microplastics Regulated the Prevalence of Antibiotic Resistance Genes in the Aquatic Environment: New Insight into the Effect of Microplastics on the Spreading of Biofilm Resistomes. The spread of antibiotic resistance genes (ARGs) by microplastics has received a great concern in coexisting "hotspots". Despite most microplastics suffering from natural aging, little is known about the effect of aging microplastics (A-MPs) on ARGs dissemination. Here, we demonstrated significant suppression of A-MPs on ARGs dissemination in natural rivers. Although ARGs and mobile genetic elements (MGEs) were effectively enriched on A-MPs, the relative abundance of ARGs and MGEs on A-MPs as well as in receiving water decreased by approximately 21.4% to 42.3% during a period of 30 days of dissemination. Further investigation revealed that (•)OH was consistently generated on A-MPs with a maximum value of 0.2 μmol/g. Importantly, scavenging of (•)OH significantly increased the relative abundance of ARGs and MGEs both on A-MPs and in receiving water 1.4-29.1 times, indicating the vital role of (•)OH in suppressing ARGs dissemination. Microbial analysis revealed that (•)OH inhibited the potential antibiotic-resistant bacteria in surface biofilms, such as Pseudomonas and Acinetobacter (with a decrease of 68.8% and 89.3%). These results demonstrated that (•)OH was extensively produced on A-MPs, which greatly reduced both the vertical and horizontal gene transfer of ARGs. This study provided new insights into the dissemination of ARGs through microplastics in natural systems.202540359213
702880.9998Metagenomic insights to effective elimination of resistomes in food waste composting by lime addition. Food waste contains abundant resistomes, including antibiotic and heavy metal resistance genes (ARGs and MRGs), which pose risks to the environment and human health. Composting can be used for food waste treatment, but it fails to effectively eliminate these resistomes. Thus, this study investigated the performance of lime to regulate the dynamics and mobility of ARGs and MRGs in food waste composting by metagenomics. Genome-resolved analysis was further conducted to identify the ARGs and MRGs hosts and their horizontal gene transfer (HGT) events. Results showed that lime addition at 1 % (wet weight) could significantly promote temperature and pH increase to sterilize hosts, particularly pathogen bacteria (e.g. Acinetobacter johnsonii and Enterobacter cloacae), thus reducing the abundance of resistomes by more than 57.1 %. This sterilization notably reduced the number of mobile ARGs and MRGs driven by mobile genetic elements (MGEs). The contribution of MGEs located on chromosomal sequences to horizontally transfer ARGs and MRGs was significantly higher than that on mobilizable plasmids. Further analysis indicated that the reduced resistomes by lime was mainly attributed to effective sterilization of hosts rather than decreased HGT diversity. Thus, this study provides valuable insights into use lime as a low-cost control of resistomes in waste recycling.202541061540
714690.9998Fate of antibiotic resistance genes and bacteria in a coupled water-processing system with wastewater treatment plants and constructed wetlands in coastal eco-industrial parks. In coastal eco-industrial zones, wastewater treatment plants (WWTPs) and constructed wetlands (CWs) can alleviate the challenge of water shortage and the negative effect of sewage discharge, while the problems of antibiotic resistance genes (ARGs) have not attracted enough attention. In this research, the Wafergen SmartChip system was adopted to investigate the ARG profiles in a coupled system combined WWTPs and CWs in a coastal industrial park. Potential risks of antibiotic resistance in chemical industrial wastewater were confirmed due to the higher abundance of target ARGs (> 10(7) copies/mL). General decline with partial enrichment in absolute and relative abundance of ARGs from the WWTPs to CWs revealed the effective removal of ARGs in the coupled system, while the fate of different ARG types varied greatly. Aminoglycoside and sulfonamide ARGs were detected with higher abundance (up to 5.34 ×10(7) and 3.61 ×10(7) copies/mL), especially aac(6')-Ib and sul1. Denitrification, secondary sedimentation, and acid hydrolysis contributed to the removal of aminoglycoside, sulfonamide, β-lactamase, chloramphenicol, and multidrug ARGs. Catalytic ozonation contributed to the removal of tetracycline and MLSB ARGs. Subsurface CWs worked effectively for the removal of sulfonamide, tetracycline, and multidrug ARGs, especially tetX, cphA, tetG, and strB. Close correlations between ARGs and MGEs emphasized the vital roles of anthropogenic pollutants and horizontal gene transfer on the diffusion of ARGs. Actinobacteria, Bacteroidota, and Cyanobacteria were dominant in the CWs, while Proteobacteria, Firmicutes, and Planctomycetota were prevalent in the WWTPs. Redundancy analysis and variance partitioning analysis indicated that transposase and water quality posed greater influences on the distribution of ARGs. Co-occurrence network revealed that potential multiple antibiotic resistant pathogenic bacteria decreased in the CWs. The coupled system has a limited effect on the reduction of ARGs and potential ARG hosts, providing a comprehensive insight into the fate of ARGs in conventional water-processing systems.202336738611
7025100.9998Aerobic composting as an effective cow manure management strategy for reducing the dissemination of antibiotic resistance genes: An integrated meta-omics study. Livestock manure is considered as an important source for spreading antibiotic resistance genes (ARGs) into the environment, and therefore poses a direct threat to public health. Whereas the effects of reused manure on soil microbial communities and ARGs have been studied extensively, comprehensive characterizations of microbial communities and ARGs of manure produced by different management methods are not well understood. Here, we analyzed the fate of microbial communities and ARGs of cow manure treated by three conventional management strategies: aerobic composting, mechanical drying and precipitation, applying an integrated-omics approach combining metagenomics and metaproteomics. Integrated-omics demonstrated that composted manure contained the lowest diversity of microbial community and ARGs compared with manure treated by other two strategies. Quantitative PCR methods revealed that the abundances of ARGs were reduced by over 83 % after composting for 14 days, regardless of the season. Besides, the potential ARG hosts Acinetobacter and Pseudomonas dominating mechanical drying process were sharply decreased in abundances after composting. The significant co-occurrence networks among bacteria, ARGs and transposase gene tnpA-01 in composting samples indicated the important role of these bacteria in the dissemination of ARGs. These findings offer insight into potential strategies to control the spread of ARGs during livestock manure reuse.202031884359
7145110.9998Antibiotic resistance genes in constructed wetlands: Driving indicators and risk assessment. Constructed wetlands (CWs) were responsible for the in-depth purification of wastewater, providing an ideal environment for the transport, acquisition, and dissemination of antibiotic resistance genes (ARGs). A better understanding of influencing factors and risks of ARGs in CWs was deemed indispensable. In this research, the abundance of ARGs and mobile genetic elements (MGEs) was determined to be higher in summer and spring, ranging from 53.7 to 8.51 × 10(6) and 30.9-6.02 × 10(6) copies/mL, respectively. Seasonal variation significantly influenced the abundance of ARGs and MGEs, as well as the co-occurrence patterns among ARGs, MGEs and bacteria. However, the environmental gradients, from the influent (CW01) to the effluent (CW10), did not impose significant effects on the abundance of ARGs and MGEs. Furthermore, the ratios of pathogenic bacteria to ARG hosts and ARG risks index decreased by 50.4% and 88.54% along with the environmental gradients, indicating that CWs could act as barriers to the transfer of ARGs. Partial least squares-path modeling (PLSPM) revealed that temperature was the main driving factor of ARGs, followed by MGEs, stable and differential bacteria. This finding effectively and innovatively explored the driving indicators for the variations and risks of ARGs caused by spatial-temporal variations, providing new insights into the evaluation and control of ARGs in CWs.202337595473
7141120.9998The fate of antibiotic resistance genes and their association with bacterial and archaeal communities during advanced treatment of pig farm wastewater. Advanced wastewater treatment plants are widely used in most large-scale pig farms in southern China. However, the fate of antibiotic resistance genes (ARGs) and their association with bacterial and archaeal communities during advanced wastewater treatment remain unclear. In this study, the profiles of ARGs in typical advanced wastewater treatment plants were surveyed using metagenomic analysis. The results showed that 279- 326 different subtypes of ARGs were detected in raw wastewater, with a total abundance of 5.98 ± 0.48 copies per bacterial cell. During the advanced wastewater treatment, the abundance and number of ARGs were significantly reduced. Microbial communities (bacteria and archaea) contributed the most to the variation in ARG abundance and composition (PCA axis_1), accounting for 10.8 % and 15.7 %, respectively, followed by mobile genetic elements (MGEs) and physicochemical factors. Special attention should be given to potential pathogenic bacteria such as Escherichia, Streptococcus, Enterococcus and Staphylococcus and archaea such as Methanocorpusculum, Candidatus Methanoplasma and Candidatus Methanomethylophilus, which were important potential ARG hosts. Bacterial communities may indirectly affect ARG variation by affecting archaeal communities. These findings indicated that ARG levels in pig farm wastewater can be effectively reduced during advanced treatment and highlighted the important role played by archaea, which should not be ignored.202236041618
7020130.9998Microbiome, resistome and mobilome of chlorine-free drinking water treatment systems. Drinking water treatment plants (DWTPs) are designed to remove physical, chemical, and biological contaminants. However, until recently, the role of DWTPs in minimizing the cycling of antibiotic resistance determinants has got limited attention. In particular, the risk of selecting antibiotic-resistant bacteria (ARB) is largely overlooked in chlorine-free DWTPs where biological processes are applied. Here, we combined high-throughput quantitative PCR and metagenomics to analyze the abundance and dynamics of microbial communities, antibiotic resistance genes (ARGs), and mobile genetic elements (MGEs) across the treatment trains of two chlorine-free DWTPs involving dune-based and reservoir-based systems. The microbial diversity of the water increased after all biological unit operations, namely rapid and slow sand filtration (SSF), and granular activated carbon filtration. Both DWTPs reduced the concentration of ARGs and MGEs in the water by circa 2.5 log gene copies mL(-1), despite their relative increase in the disinfection sub-units (SSF in dune-based and UV treatment in reservoir-based DWTPs). The total microbial concentration was also reduced (2.5 log units), and none of the DWTPs enriched for bacteria containing genes linked to antibiotic resistance. Our findings highlight the effectiveness of chlorine-free DWTPs in supplying safe drinking water while reducing the concentration of antibiotic resistance determinants. To the best of our knowledge, this is the first study that monitors the presence and dynamics of antibiotic resistance determinants in chlorine-free DWTPs.202336989799
6943140.9998Insights into the reduction of antibiotic-resistant bacteria and mobile antibiotic resistance genes by black soldier fly larvae in chicken manure. The increasing prevalence of antibiotic-resistant bacteria (ARB) from animal manure has raised concerns about the potential threats to public health. The bioconversion of animal manure with insect larvae, such as the black soldier fly larvae (BSFL, Hermetia illucens [L.]), is a promising technology for quickly attenuating ARB while also recycling waste. In this study, we investigated BSFL conversion systems for chicken manure. Using metagenomic analysis, we tracked ARB and evaluated the resistome dissemination risk by investigating the co-occurrence of antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and bacterial taxa in a genetic context. Our results indicated that BSFL treatment effectively mitigated the relative abundance of ARB, ARGs, and MGEs by 34.9%, 53.3%, and 37.9%, respectively, within 28 days. Notably, the transferable ARGs decreased by 30.9%, indicating that BSFL treatment could mitigate the likelihood of ARG horizontal transfer and thus reduce the risk of ARB occurrence. In addition, the significantly positive correlation links between antimicrobial concentration and relative abundance of ARB reduced by 44.4%. Moreover, using variance partition analysis (VPA), we identified other bacteria as the most important factor influencing ARB, explaining 20.6% of the ARB patterns. Further analysis suggested that antagonism of other bacteria on ARB increased by 1.4 times, while nutrient competition on both total nitrogen and crude fat increased by 2.8 times. Overall, these findings provide insight into the mechanistic understanding of ARB reduction during BSFL treatment of chicken manure and provide a strategy for rapidly mitigating ARB in animal manure.202337832484
6881150.9998Spatiotemporal profiles and underlying mechanisms of the antibiotic resistome in two water-diversion lakes. Human-induced interventions have altered the local characteristics of the lake ecosystems through changes in hydraulic exchange, which in turn impacts the ecological processes of antibiotic resistance genes (ARGs) in the lakes. However, the current understanding of the spatiotemporal patterns and driving factors of ARGs in water-diversion lakes is still seriously insufficient. In the present study, we investigated antibiotic resistome in the main regulation and storage hubs, namely Nansi Lake and Dongping Lake, of the eastern part of the South-to-North Water Diversion project in Shandong Province (China) using a metagenomic-based approach. A total of 653 ARG subtypes belonging to 25 ARG types were detected with a total abundance of 0.125-0.390 copies/cell, with the dominance of bacitracin, multidrug, and macrolide-lincosamide streptogramin resistance genes. The ARG compositions were sensitive to seasonal variation and also interfered by artificial regulation structures along the way. Human pathogenic bacteria such as Acinetobacter calcoaceticus, Acinetobacter lwoffii, Klebsiella pneumoniae, along with the multidrug resistance genes they carried, were the focus of risk control in the two studied lakes, especially in summer. Plasmids were the key mobile genetic elements (MGEs) driving the horizontal gene transfer of ARGs, especially multidrug and sulfonamide resistance genes. The null model revealed that stochastic process was the main driver of ecological drift for ARGs in the lakes. The partial least squares structural equation model further determined that seasonal changes of pH and temperature drove a shift in the bacterial community, which in turn shaped the profile of ARGs by altering the composition of MGEs, antibacterial biocide- and metal-resistance genes (BMGs), and virulence factor genes (VFGs). Our results highlighted the importance of seasonal factors in determining the water transfer period. These findings can aid in a deeper understanding of the spatiotemporal variations of ARGs in lakes and their driving factors, offering a scientific basis for antibiotic resistance management.202439322056
7329160.9998Metagenomic 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
7017170.9998Metagenome sequencing to unveil the occurrence and distribution of antibiotic resistome and in a wastewater treatment plant. The emergence and persistence of antibiotic resistance genes (ARGs) in wastewater treatment plants (WWTPs) has aroused growing public concern for its risk to human health and ecological safety. Moreover, heavy metals concentrated in sewage and sludge could potentially favour co-selection of ARGs and heavy metal resistance genes (HMRGs). In this study, the profile and abundance of antibiotic and metal resistance genes in influent, sludge and effluent were characterized based on the Structured ARG Datebase (SARG) and Antibacterial Biocide and Metal Resistance Gene Datebase (BacMet) by metagenomic analysis. Sequences were aligning against the INTEGRALL, ISFinder, ICEberg and NCBI RefSeq databases to obtain the diversity and abundance of mobile genetic elements (MGEs, e.g.plasmid and transposon). Among them, 20 types of ARGs and 16 types of HMRG were detected in all samples, the influent metagenomes contained many more resistance genes (both ARGs and HMRGs) than the sludge and the influent sample, large reductions in the relatively abundance and diversity of ARG were achieved by biological treatment. ARGs and HMRGs cannot be completely eliminated during the oxidation ditch. A total of 32 species of the potential pathogens were detected, relative abundances of pathogens had no obvious changes. It is suggested that more specific treatments are required to limit their proliferation in the environment. This study can be helpful for further understanding the removal of antibiotic resistance genes in the sewage treatment process via metagenomic sequencing.202436812908
6813180.9998Spread performance and underlying mechanisms of pathogenic bacteria and antibiotic resistance genes adhered on microplastics in the sediments of different urban water bodies. Urban water bodies often pose frequent human activities, the pollution of microplastics (MPs) in these sediments, and pathogenic bacteria and antibiotic resistance genes (ARGs) enriched on the MPs may have risk to human health. However, there is little known about these issues. In this paper, three typical urban water bodies (the urban park lake, the urban inland river, and the urban-rural lake) were selected to identify the characteristics of MPs. Furthermore, the enrichment and driving mechanisms of pathogenic bacteria and ARGs on MPs in sediments were studied. These three water bodies were polluted with MPs, dominated by polyethylene (PE)-MPs and polystyrene (PS)-MPs. Gammaproteobacteria, Pseudomonadota, etc. as the main types of pathogenic bacteria, with Pseudomonas aeruginosa and Acinetobacter baumannii as significantly enriched in the urban inland rivers. The predominant ARGs were bacitracin- (bacA) and sulfonamide- (sul1) resistant ARGs. Transposase was the main genetic elements that drove the transfer of ARGs and the main resistance mechanism of ARGs was antibiotic efflux. The enrichment behavior of pathogenic bacteria and ARGs on MPs was also driven by the types of MPs, especially PS-MPs. The pathogenic bacteria at urban inland rivers had more types of ARGs, transfer elements and resistance mechanisms, thus the risk of pathogenic bacteria resistance needed specific concern. The results of our study were of great significance to gain insights into the pathogenic resistance risks and ecological risks of pathogenic bacteria and ARGs in sediments of urban water bodies.202540609890
7014190.9998Correlations among Antibiotic Resistance Genes, Mobile Genetic Elements and Microbial Communities in Municipal Sewage Treatment Plants Revealed by High-Throughput Sequencing. Municipal sewage treatment plants (MSTPs) are environmental pools for antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs), which is cause for growing environmental-health concerns. In this study, the effects of different wastewater treatment processes on microbial antibiotic resistance in four MSTPs were investigated. PCR, q-PCR, and molecular cloning integrally indicated that the tetracycline resistance (tet) genes significantly reduced after activated-sludge treatment. Illumina high-throughput sequencing revealed that the broad-spectrum profile of ARGs and mobile element genes (MGEs) were also greatly decreased by one order of magnitude via activated sludge treatment and were closely associated with each other. Correlations between ARGs and bacterial communities showed that potential ARB, such as Acinetobacter, Bacteroides, and Cloaibacterium, were removed by the activated-sludge process. Sedimentation processes cannot significantly affect the bacterial structure, resulting in the relative abundance of ARGs, MGEs, and ARB in second-clarifier effluent water being similar to activated sludge. A comprehensive study of ARGs associated with MGEs and bacterial structure might be technologically guided for activated sludge design and operation in the MSTPs, to purposefully control ARGs carried by pathogenic hosts and mobility.202336834289