# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 6939 | 0 | 0.9903 | Field ponding water exacerbates the dissemination of manure-derived antibiotic resistance genes from paddy soil to surrounding waterbodies. Farmlands fertilized with livestock manure-derived amendments have become a hot topic in the dissemination of antibiotic resistance genes (ARGs). Field ponding water connects rice paddies with surrounding water bodies, such as reservoirs, rivers, and lakes. However, there is a knowledge gap in understanding whether and how manure-borne ARGs can be transferred from paddy soil into field ponding water. Our studies suggest that the manure-derived ARGs aadA1, bla1, catA1, cmlA1-01, cmx(A), ermB, mepA and tetPB-01 can easily be transferred into field ponding water from paddy soil. The bacterial phyla Crenarchaeota, Verrucomicrobia, Cyanobacteria, Choloroflexi, Acidobacteria, Firmicutes, Bacteroidetes, and Actinobacteria are potential hosts of ARGs. Opportunistic pathogens detected in both paddy soil and field ponding water showed robust correlations with ARGs. Network co-occurrence analysis showed that mobile genetic elements (MGEs) were strongly correlated with ARGs. Our findings highlight that manure-borne ARGs and antibiotic-resistant bacteria in paddy fields can conveniently disseminate to the surrounding waterbodies through field ponding water, posing a threat to public health. This study provides a new perspective for comprehensively assessing the risk posed by ARGs in paddy ecosystems. | 2023 | 37007487 |
| 8105 | 1 | 0.9898 | Refluxing mature compost to replace bulking agents: A low-cost solution for suppressing antibiotic resistance genes rebound in sewage sludge composting. Antibiotic resistance genes (ARGs) rebounding during composting cooling phase is a critical bottleneck in composting technology that increased ARGs dissemination and application risk of compost products. In this study, mature compost (MR) was used as a substitute for rice husk (RH) to mitigate the rebound of ARGs and mobile genetic elements (MGEs) during the cooling phase of sewage sludge composting, and the relationship among ARGs, MGEs, bacterial community and environmental factors was investigated to explore the key factor influencing ARGs rebound. The results showed that aadD, blaCTX-M02, ermF, ermB, tetX and vanHB significantly increased 4.76-32.41 times, and the MGEs rebounded by 38.60% in the cooling phase of RH composting. Conversely, MR reduced aadD, tetM, ermF and ermB concentrations by 59.49-98.58%, and reduced the total abundance of ARGs in the compost product by 49.32% compared to RH, which significantly restrained ARGs rebound. MR promoted secondary high temperature inactivation of potential host bacteria, including Ornithinibacter, Rhizobiales and Caldicoprobacter, which could harbor aadE, blaCTX-M02, and blaVEB. It also reduced the abundance of lignocellulose degrading bacteria of Firmicutes, which were potential hosts of aadD, tetX, ermF and vanHB. Moreover, MR reduced moisture and increased oxidation reduction potential (ORP) that promoted aadE, tetQ, tetW abatement. Furthermore, MR reduced 97.36% of total MGEs including Tn916/1545, IS613, Tp614 and intI3, which alleviated ARGs horizontal transfer. Overall finding proposed mature compost reflux as bulking agent was a simple method to suppress ARGs rebound and horizontal transfer, improve ARGs removal and reduce composting plant cost. | 2025 | 39798649 |
| 7138 | 2 | 0.9896 | Accumulation and translocation of antibiotic resistance genes in plants cultivated in hydroponic systems with nitrified biogas slurry. Hydroponic cultivation with biogas slurry supports nutrient recycling but raises biosafety concerns due to the dissemination of antibiotic resistance genes (ARGs). This study established a hydroponic system using nitrified biogas slurry to grow lettuce and cherry radish, and systematically investigated the accumulation of ARGs, mobile genetic elements (MGEs), high-priority human pathogenic bacteria (HPBs), and virulence factors (VFs) in plant tissues. ARGs predominantly accumulated in roots (0.16 ∼ 0.23 copies/16S rRNA), significantly higher than in leaves (0.01 ∼ 0.11 copies/16S rRNA), with sul1 consistently enriched in the rhizosphere. Filtration pretreatment significantly reduced ARG and MGE levels in cherry radish roots by 30.78 % and 39.43 %, respectively (p < 0.05). ARGs strongly correlated with MGEs (R² = 0.97, p < 0.0001), indicating horizontal gene transfer as the key dissemination pathway. Co-occurrence network analysis revealed synergistic enrichment of ARGs and MGEs with HPBs and VFs, highlighting Acinetobacter baumannii and Streptococcus pneumoniae as potential core hosts. These findings demonstrate that ARG accumulation and spread in plants are affected by slurry treatment, plant species, and tissue specificity. While filtration mitigates risks, persistent ARGs in roots necessitate further monitoring. This study informs safe reuse strategies for biogas slurry in agriculture. | 2025 | 41076908 |
| 8098 | 3 | 0.9894 | Elimination of antibiotic resistance genes and human pathogenic bacteria by earthworms during vermicomposting of dewatered sludge by metagenomic analysis. This study used a metagenomic approach to investigate the effects of earthworms on ARGs and HPB during the vermicomposting of dewatered sludge. Results showed that 139 types of ARGs were found in sludge vermicompost, affiliated to 30 classes. Compared with the control, the total abundance of ARGs in sludge vermicompost decreased by 41.5%. Moreover, the types and sequences of plasmids and integrons were also decreased by vermicomposting. Proteobacteria and Actinobacteria were the most dominant hosts of ARGs in sludge vermicompost. In addition, earthworms reduced the total HPB abundance and modified their diversity, thus leading to higher abundance of Enterobacteriaceae in sludge vermicompost. However, the sludge vermicompost was still ARG and HPB enriched, indicating a remaining environmental risk for agricultural purpose. The observed change of microbial community and the reduction of mobile genetic elements caused by earthworm activity are the main reasons for the alleviation of ARG pollution during vermicomposting. | 2020 | 31787516 |
| 7167 | 4 | 0.9893 | Occurrence and distribution of antibiotic pollution and antibiotic resistance genes in seagrass meadow sediments based on metagenomics. Seagrass meadows are one of the most important coastal ecosystems that provide essential ecological and economic services. The contamination levels of antibiotic and antibiotic resistance genes (ARGs) in coastal ecosystems are severely elevated owing to anthropogenic disturbances, such as terrestrial input, aquaculture effluent, and sewage discharge. However, few studies have focused on the occurrence and distribution of antibiotics and their corresponding ARGs in this habitat. Thus, we investigated the antibiotic and ARGs profiles, microbial communities, and ARG-carrying host bacteria in typical seagrass meadow sediments collected from Swan Lake, Caofeidian shoal harbor, Qingdao Bay, and Sishili Bay in the Bohai Sea and northern Yellow Sea. The total concentrations of 30 detected antibiotics ranged from 99.35 to 478.02 μg/kg, tetracyclines were more prevalent than other antibiotics. Metagenomic analyses showed that 342 ARG subtypes associated with 22 ARG types were identified in the seagrass meadow sediments. Multidrug resistance genes and RanA were the most dominant ARG types and subtypes, respectively. Co-occurrence network analysis revealed that Halioglobus, Zeaxanthinibacter, and Aureitalea may be potential hosts at the genus level, and the relative abundances of these bacteria were higher in Sishili Bay than those in other areas. This study provided important insights into the pollution status of antibiotics and ARGs in typical seagrass meadow sediments. Effective management should be performed to control the potential ecological health risks in seagrass meadow ecosystems. | 2024 | 38782270 |
| 7235 | 5 | 0.9893 | Unveiling the characteristics of free-living and particle-associated antibiotic resistance genes associated with bacterial communities along different processes in a full-scale drinking water treatment plant. Antibiotic resistance genes (ARGs) as emerging contaminants, often co-occur with mobile genetic elements (MGEs) and are prevalent in drinking water treatment plants (DWTPs). In this study, the characteristics of free-living (FL) and particle-associated (PA) ARGs associated with bacterial communities were investigated along two processes within a full-scale DWTP. A total of 13 ARGs and two MGEs were detected. FL-ARGs with diverse subtypes and PA-ARGs with high abundances displayed significantly different structures. PA-MGEs showed a strong positive correlation with PA-ARGs. Chlorine dioxide disinfection achieved 1.47-log reduction of FL-MGEs in process A and 0.24-log reduction of PA-MGEs in process B. Notably, PA-fraction virtually disappeared after treatment, while blaTEM, sul2, mexE, mexF and IntI1 of FL-fraction remained in the finished water. Moreover, Acinetobacter lwoffii (0.04 % ∼ 45.58 %) and Acinetobacter schindleri (0.00 % ∼ 18.54 %) dominated the 16 pathogens, which were more abundant in FL than PA bacterial communities. PA bacteria exhibited a more complex structure with more keystone species than FL bacteria. MGEs contributed 20.23 % and 19.31 % to the changes of FL-ARGs and PA-ARGs respectively, and water quality was a key driver (21.73 %) for PA-ARGs variation. This study provides novel insights into microbial risk control associated with size-fractionated ARGs in drinking water. | 2024 | 39003808 |
| 7219 | 6 | 0.9892 | Occurrence and human exposure risk of antibiotic resistance genes in tillage soils of dryland regions: A case study of northern Ningxia Plain, China. Agricultural soils are important source and sink of antibiotic resistance genes (ARGs). However, little is known about the fate of ARGs in dryland soils, while its human exposure risks were seriously overlooked. Taking the northern Ningxia Plain as a case, this study explored the occurrence of ARGs and its relationship with mobile genetic elements (MGEs), pathogens, and environmental factors. Furthermore, the concentrations of airborne ARGs by soil wind erosion and the human exposure doses of soil ARGs were evaluated. The results showed the abundances of different regions ranged from 4.0 × 10(5) to 1.6 × 10(6) copies/g. Soil ARGs are driven by MGEs, but multiply impacted by soil properties, nutrition, and bacterial community. Vibrio metschnikovii, Acinetobacter schindleri, and Serratia marcescens are potential pathogenic hosts for ARGs. Further exploration revealed the concentration of ARGs loaded in dust by soil wind erosion reached more than 10(5) copies/m(3), which were even higher than those found in sewage treatment plants and hospitals. Skin contact is the primary route of ARGs exposure, with a maximum dose of 24071.33 copies/kg/d, which is largely attributed to ARGs loaded in dust. This study bridged the gap on ARGs in dryland soils, and provided reference for human exposure risk assessment of soil ARGs. | 2024 | 39276744 |
| 7578 | 7 | 0.9892 | Dissemination of sulfonamide resistance genes in digester microbiome during anaerobic digestion of food waste leachate. The preeminence of sulfonamide drug resistance genes in food waste (FW) and the increased utilization of high-strength organic FW in anaerobic digestion (AD) to enhance methane production have raised severe public health concerns in wastewater treatment plants worldwide. In this regard, the dissemination patterns of different sulfonamide resistance genes (sul1 and sul2) and their impact on the digester core microbiota during AD of FW leachate (FWL) were evaluated. The presence of various sulfonamide antibiotics (SAs) in FWL digesters improved the final methane yield by 37 % during AD compared with FWL digesters without SAs. Microbial population shifts towards hydrolytic, acidogenic, and acetogenic bacteria in the phyla Actinobacteriota, Bacteroidota, Chloroflexi, Firmicutes, Proteobacteria, and Synergistota occurred due to SA induced substrate digestion and absorption through active transport; butanoate, propanoate, and pyruvate metabolism; glycolysis; gluconeogenesis; the citrate cycle; and pentose phosphate pathway. The initial dominance of Methanosaeta (89-96 %) declined to 47-53 % as AD progressed and shifted towards Methanosarcina (40 %) in digesters with the highest SA concentrations at the end of AD. Dissemination of sul1 depended on class 1 integron gene (intl1)-based horizontal gene transfer to pathogenic members of Chloroflexi, Firmicutes, and Patescibacteria, whereas sul2 was transmitted to Synergistota independent of intl1. Low susceptibility and ability to utilize SAs during methanogenesis shielded methanogenic archaea against selection pressure, thus preventing them from interacting with sul or intl1 genes, thereby minimizing the risk of antibiotic resistance development. The observed emergence of cationic antimicrobial peptide, vancomycin, and β-lactam resistance in the core microbiota during AD of FWL in the presence of SAs suggests that multidrug resistance caused by bacterial transformation could lead to an increase in the environmental resistome through wastewater sludge treatment. | 2023 | 36958158 |
| 7147 | 8 | 0.9892 | Comprehensive analysis and risk assessment of Antibiotic contaminants, antibiotic-resistant bacteria, and resistance genes: Patterns, drivers, and implications in the Songliao Basin. The pervasive use of antibiotics has raised substantial environmental concerns, especially regarding their temporal and spatial distribution across diverse water systems. This study addressed the gap in comprehensive research on antibiotic contamination during different hydrological periods, focusing on the Jilin section of the Songliao Basin in Northeast China, an area with severe winter ice cover. The study examined the occurrence, distribution, influencing factors, and potential ecological risks of prevalent antibiotic contaminants. Findings revealed antibiotic concentrations ranging from 239.64 to 965.81 ng/L, with antibiotic resistance genes (ARGs) at 5.22 × 10(-2) 16S rRNA(-1) and antibiotic-resistant bacteria (ARB) up to 5.76 log(10) CFU/mL. Ecological risk assessments identified significant risks to algae from oxytetracycline, erythromycin, and amoxicillin. Redundancy analysis and co-occurrence networks with ordinary least squares (OLS) demonstrated that the dispersion of ARGs and ARB is significantly influenced by environmental factors such as total organic carbon (TOC), total phosphorus (TP), total nitrogen (TN), fluoride (F⁻), and nitrate (NO₃⁻). These elements, along with mobile genetic elements (MGEs), play crucial roles in ARG patterns (R(2) = 0.94, p ≤ 0.01). This investigation offers foundational insights into antibiotic pollution dynamics in cold climates, supporting the development of targeted mitigation strategies for aquatic systems. | 2024 | 39216670 |
| 7145 | 9 | 0.9891 | Antibiotic 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. | 2023 | 37595473 |
| 7018 | 10 | 0.9890 | Shotgun 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. | 2021 | 34329002 |
| 7019 | 11 | 0.9890 | Fate, 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. | 2025 | 40587929 |
| 7148 | 12 | 0.9890 | Metagenomic analysis revealed sources, transmission, and health risk of antibiotic resistance genes in confluence of Fenhe, Weihe, and Yellow Rivers. Rivers are important vectors and reservoirs of antibiotics resistance genes (ARGs). Information regarding transmission and health risk of ARGs in river confluence is still lacking. In this study, metagenomics was used to distinguish contributions of human activities on ARGs and human pathogenic bacteria (HPB) in confluence of Fenhe, Weihe, and Yellow Rivers. Bacitracin resistance gene and bacA were the highest in all rivers, with 1.86 × 10(-2)-7.26 × 10(-2) and 1.79 × 10(-2)-9.12 × 10(-2) copies/16S rRNA copies, respectively. River confluence significantly increased the abundance of ARGs, especially at the confluence of three rivers with the highest 1.53 × 10(-1) copies/16S rRNA copies. Antibiotic efflux and antibiotic target alteration were the dominant resistant mechanisms in three rivers. ARGs profiles were influenced by multiple factors, with the contributions of various factors ranked as microbial communities > physicochemical factors > human activities > mobile genetic elements (MGEs). Notably, human activities and animal feces were important potential contributors of ARGs in the Weihe River and Yellow River. Transposons, as the main MGEs in three rivers, played important roles in ARGs transfer. The confluence of three rivers had the highest abundance of MGEs with the greatest transfer potentials, and therefore exhibiting the largest exposure risk of ARGs with 232.4 copies/cap·d. Furthermore, correlations of ARGs, MGEs, and HPB in different rivers were constructed via co-occurrence modes to systematically illustrate the health risks of ARGs. This study firstly unveiled the transmission and health risk of ARGs in river confluence, providing supports for ARGs control in watershed. | 2023 | 36343807 |
| 8110 | 13 | 0.9890 | Removal of chlortetracycline and antibiotic resistance genes in soil by earthworms (epigeic Eisenia fetida and endogeic Metaphire guillelmi). The impacts of two ecological earthworms on the removal of chlortetracycline (CTC, 0.5 and 15 mg kg(-1)) and antibiotic resistance genes (ARGs) in soil were explored through the soil column experiments. The findings showed that earthworm could significantly accelerate the degradation of CTC and its metabolites (ECTC) in soil (P < 0.05), with epigeic Eisenia fetida promoting degradation rapidly and endogeic Metaphire guillelmi exhibiting a slightly better elimination effect. Earthworms alleviated the abundances of tetR, tetD, tetPB, tetG, tetA, sul1, TnpA, ttgB and intI1 in soil, with the total relative abundances of ARGs decreasing by 35.0-44.2% in earthworm treatments at the 28th day of cultivation. High throughput sequencing results displayed that the structure of soil bacteria community was modified apparently with earthworm added, and some possible CTC degraders, Aeromonas, Flavobacterium and Luteolibacter, were promoted by two kinds of earthworms. Redundancy analysis demonstrated that the reduction of CTC residues, Actinobacteria, Acidobacteria and Gemmatimonadetes owing to earthworm stimulation was responsible for the removal of ARGs and intI1 in soil. Additionally, intI1 declined obviously in earthworm treatments, which could weaken the risk of horizontal transmission of ARGs. Therefore, earthworm could restore the CTC-contaminated soil via enhancing the removal of CTC, its metabolites and ARGs. | 2021 | 33798888 |
| 8058 | 14 | 0.9890 | Effects of biochars on the fate of antibiotics and their resistance genes during vermicomposting of dewatered sludge. It is currently still difficult to decrease the high contents of antibiotics and their corresponding antibiotic resistance genes (ARGs) in sludge vermicompost. To decrease the environmental risk of vermicompost as a bio-fertilizer, this study investigated the feasibility of biochar addition to decrease the levels of antibiotics and ARGs during vermicomposting of dewatered sludge. To achieve this, 1.25% and 5% of corncob and rice husk biochars, respectively, were added to sludge, which was then vermicomposted by Eisenia fetida for 60 days. The sludge blended with corncob biochar showed increased decomposition and humification of organic matter. Higher biochar concentration promoted both the number and diversity of bacteria, and differed dominant genera. The level of antibiotics significantly decreased as a result of biochar addition (P < 0.05), and tetracycline was completely removed. Relative to the control without addition of biochars, ermF and tetX genes significantly decreased with corncob biochar treatment (P < 0.05). Rice husk biochar (5%) could effectively decrease sul-1 and sul-2 genes in vermicompost (P < 0.05). However, the abundance of the intI-1 gene increased with biochar concentration. This study suggests that biochar addition can lessen the antibiotic and ARG pollution in sludge vermicompost, depending on the type and concentration of biochars. | 2020 | 32388093 |
| 8104 | 15 | 0.9890 | Comparative network analysis revealing the mechanisms of antibiotic resistance genes removal by leachate recirculation under different hydraulic loadings. The wide dissemination of antibiotic resistance is a pervasive global health threat, and landfill leachate has been an important hotspot of antibiotic resistance genes (ARGs). This study aimed to investigate the removal performance and mechanism of ARGs from leachate under different hydraulic loadings. ARGs removal efficiencies were dependent on hydraulic loadings and ARGs types other than operating time, and reactors operated with hydraulic loadings of 25 and 50 L·m(-3)·d(-1) exhibited greater removal potential than 100 L·m(-3)·d(-1). ARGs removal patterns varied from different subtypes, for genes sul2, tetQ, aadA1 and bla(CTX-M) were eliminated from both leachate and refuse, and tetM, ermB, mefA, and strB were removed from leachate but enriched in refuse. Under different hydraulic loadings, bacterial communities shift shaped ARGs fates in leachate, but refuse had more stable antibiotic resistome and community structure. The topology comparison analysis of co-occurrence network suggested a closer hosting relationship between ARGs and genera in refuse than leachate. Furthermore, taxonomic category of host bacteria other than diversity of host genera determined the ARGs removal, and the ARGs harbored in phyla Cyanobacteria, Tenericutes and Acidobacteria were more likely to be removed. These findings can potentially foster the understanding of ARGs removal mechanism in biological treatment processes under different operating conditions. | 2019 | 30176445 |
| 7942 | 16 | 0.9890 | Insight into effects of polyethylene microplastics in anaerobic digestion systems of waste activated sludge: Interactions of digestion performance, microbial communities and antibiotic resistance genes. The environmental risks of microplastics (MPs) have raised an increasing concern. However, the effects of MPs in anaerobic digestion (AD) systems of waste activated sludge (WAS), especially on the fate of antibiotic resistance genes (ARGs), have not been clearly understood. Herein, the variation and interaction of digestion performance, microbial communities and ARGs during AD process of WAS in the presence of polyethylene (PE) MPs with two sizes, PE MPs-180μm and PE MPs-1mm, were investigated. The results showed that the presence of PE MPs, especially PE MPs-1mm, led to the increased hydrolysis of soluble polysaccharides and proteins and the accumulation of volatile fatty acids. The methane production decreased by 6.1% and 13.8% in the presence of PE MPs-180μm and PE MPs-1mm, respectively. Together with this process, hydrolytic bacteria and acidogens were enriched, and methanogens participating in acetoclastic methanogenesis were reduced. Meanwhile, ARGs were enriched obviously by the presence of PE MPs, the abundances of which in PE MPs-180μm and PE MPs-1mm groups were 1.2-3.0 times and 1.5-4.0 times higher than that in the control by the end of AD. That was associated with different co-occurrence patterns between ARGs and bacterial taxa and the enrichment of ARG-hosting bacteria caused by the presence of PE MPs. Together these results suggested the adverse effects of PE MPs on performance and ARGs removal during AD process of WAS through inducing the changes of microbial populations. | 2022 | 35944782 |
| 7146 | 17 | 0.9890 | Fate 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. | 2023 | 36738611 |
| 7743 | 18 | 0.9889 | Integrated meta-omics study on rapid tylosin removal mechanism and dynamics of antibiotic resistance genes during aerobic thermophilic fermentation of tylosin mycelial dregs. For efficient treatment of tylosin mycelial dregs (TMDs), rapid tylosin removal mechanism and dynamics of ARGs during TMDs fermentation were investigated using integrated meta-omics (genomics, metaproteomics and metabolomics) and qPCR approaches. The results showed that over 86% of tylosin was degraded on day 7 regardless of the type of bulking agents. The rapid removal of tylosin was mainly attributed to de-mycarose reaction (GH3) and esterase hydrolysis (C7MYQ7) of Saccharomonospora, and catalase-peroxidase oxidation of Bacillus (A0A077JB13). In addition, the moisture content and mobile genetic elements were vital to control the rebound of ARGs. The removal efficiency of antibiotic resistant bacteria (Streptomyces, Pseudomonas, norank_f__Sphingobacteriaceae, and Paenalcaligenes) and Intl1 (98.8%) in fermentation treatment TC21 with corncob as the bulking agent was significantly higher than that in other three treatments (88.3%). Thus, appropriate bulking agents could constrain the abundance of antibiotic resistant bacteria and Intl1, which is crucial to effectively reduce the resistance. | 2022 | 35307520 |
| 6907 | 19 | 0.9889 | Deciphering the impact of organic loading rate and digestate recirculation on the occurrence patterns of antibiotics and antibiotic resistance genes in dry anaerobic digestion of kitchen waste. Organic loading rate (OLR) is crucial for determining the stability of dry anaerobic digestion (AD). Digestate recirculation contributes to reactor stability and enhances methane production. Nevertheless, the understanding of how OLR and digestate recirculation affect the abundance and diversity of antibiotics and antibiotic resistance genes (ARGs), as well as the mechanisms involved in the dissemination of ARGs, remains limited. This study thoroughly investigated this critical issue through a long-term pilot-scale experiment. The metabolome analyses revealed the enrichment of various antibiotics, such as aminoglycoside, tetracycline, and macrolide, under low OLR conditions (OLR ≤ 4.0 g·VS/L·d) and the reactor instability. Antibiotics abundance decreased by approximately 19.66-31.69 % during high OLR operation (OLR ≥ 6.0 g·VS/L·d) with digestate recirculation. The metagenome analyses demonstrated that although low OLR promoted reactor stability, it facilitated the proliferation of antibiotic-resistant bacteria, such as Pseudomonas, and triggered functional profiles related to ATP generation, oxidative stress response, EPS secretion, and cell membrane permeability, thereby facilitating horizontal gene transfer (HGT) of ARGs. However, under stable operation at an OLR of 6.0 g·VS/L·d, there was a decrease in ARGs abundance but a notable increase in human pathogenic bacteria (HPB) and mobile genetic elements (MGEs). Subsequently, during reactor instability, the abundance of ARGs and HPB increased. Notably, during digestate recirculation at OLR levels of 6.0 and 7.0 g·VS/L·d, the process attenuated the risk of ARGs spread by reducing the diversity of ARGs hosts, minimizing interactions among ARGs hosts, ARGs, and MGEs, and weakening functional profiles associated with HGT of ARGs. Overall, digestate recirculation aids in reducing the abundance of antibiotics and ARGs under high OLR conditions. These findings provide advanced insights into how OLR and digestate recirculation affect the occurrence patterns of antibiotics and ARGs in dry AD. | 2024 | 38968733 |