Antibiotic resistance reduction mechanisms during thermophilic anaerobic digestion of microalgae-bacteria aggregates. - Related Documents




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754401.0000Antibiotic resistance reduction mechanisms during thermophilic anaerobic digestion of microalgae-bacteria aggregates. Microalgae-bacteria-based systems are an emerging and promising approach for wastewater treatment plants (WWTP), having nutrient and antibiotic resistance removal comparable to conventional technologies. Still, antibiotic-resistance genes and bacteria (ARG and ARB) can proliferate in microalga-bacteria aggregates (MABA), a concern to control. Different temperature regimes of MABA continuous anaerobic digestion (AD), thermophilic (55 °C), and mesophilic (35 °C) were evaluated in this study as a strategy to eliminate ARB and ARGs. Plate counting techniques and metagenomic-based analysis revealed that thermophilic temperature had a better performance, achieving ARB log reductions of 1.1 to 1.7 for various antibiotics and significantly reduced ARG abundance up to 19.5 ± 0.8 ppm. The microbiome selection, the mobilome restriction, and directed functionality to thermal stress resistance were the main mechanisms responsible for resistome reduction at thermophilic conditions. Thermophilic AD effectively manages antibiotic resistance in microalgae-bacteria aggregates, which has important implications for wastewater treatment and reduces environmental risks.202539756663
754710.9998Mechanism concerning the occurrence and removal of antibiotic resistance genes in composting product with ozone post-treatment. The soil application of composting product will probably cause the spread of antibiotic resistance genes (ARGs) to environment, thereby it is crucial to remove ARGs in composting product. Ozone was adopted for the first time as a post-treatment method to remove the ARGs in composting product in this study. Ozone treatment significantly removed the total ARGs and mobile genetic elements (MGEs) once ozonation process finished. After 10-day storage stage, although the amount of total intracellular ARGs and MGEs increased, the total extracellular ARGs and MGEs decreased in the ozone-treated compost product. Correlation analysis revealed that the reduction in intracellular 16S rRNA contributed to intracellular tetQ and tetW removal, while the variations of other ARGs after ozonation related to MGEs abundance. Network analysis suggested that the reduction of potential host bacteria, as well as the decline in NH(4)(+)-N and TOC after the ozonation, contributed to the intracellular ARGs removal.202133257169
702320.9998Metagenomic absolute quantification of antibiotic resistance genes and virulence factor genes-carrying bacterial genomes in anaerobic digesters. Sewage treatment works have been considered as hotspots for the dissemination of antibiotic resistance genes (ARGs). Anaerobic digestion (AD) has emerged as a promising approach for controlling the spread of ARGs while destroying biomass in sludge. Evaluating the impact of AD on ARG removal relies on the absolute quantification of ARGs. In this study, we quantified the ARG concentrations in both full-scale and lab-scale AD systems using a cellular spike-ins based absolute quantification approach. Results demonstrated that AD effectively removed 68 ± 18 %, 55 ± 12 %, and 57 ± 19 % of total ARGs in semi-continuous AD digesters, with solid retention times of 15, 20, and 25 days, respectively. The removal efficiency of total ARGs increased as the AD process progressed in the batch digesters over 40 days. A significant negative correlation was observed between digestion time and the concentrations of certain ARG types, such as beta-lactam, sulfonamide, and tetracycline. However, certain potential pathogenic antibiotic resistant bacteria (PARB) and multi-resistant high-risk ARGs-carrying populations robustly persisted throughout the AD process, regardless of the operating conditions. This study highlighted the influence of the AD process and its operating parameters on ARG removal, and revealed the broad spectrum and persistence of PARB in AD systems. These findings provided critical insights for the management of microbial hazards.202438359594
755230.9998Effect of temperature on removal of antibiotic resistance genes by anaerobic digestion of activated sludge revealed by metagenomic approach. As antibiotic resistance continues to spread globally, there is growing interest in the potential to limit the spread of antibiotic resistance genes (ARGs) from wastewater sources. In particular, operational conditions during sludge digestion may serve to discourage selection of resistant bacteria, reduce horizontal transfer of ARGs, and aid in hydrolysis of DNA. This study applied metagenomic analysis to examine the removal efficiency of ARGs through thermophilic and mesophilic anaerobic digestion using bench-scale reactors. Although the relative abundance of various ARGs shifted from influent to effluent sludge, there was no measureable change in the abundance of total ARGs or their diversity in either the thermophilic or mesophilic treatment. Among the 35 major ARG subtypes detected in feed sludge, substantial reductions (removal efficiency >90%) of 8 and 13 ARGs were achieved by thermophilic and mesophilic digestion, respectively. However, resistance genes of aadA, macB, and sul1 were enriched during the thermophilic anaerobic digestion, while resistance genes of erythromycin esterase type I, sul1, and tetM were enriched during the mesophilic anaerobic digestion. Efflux pump remained to be the major antibiotic resistance mechanism in sludge samples, but the portion of ARGs encoding resistance via target modification increased in the anaerobically digested sludge relative to the feed. Metagenomic analysis provided insight into the potential for anaerobic digestion to mitigate a broad array of ARGs.201525994259
808340.9998Alteration of the migration trajectory of antibiotic resistance genes by microplastics in a leachate activated sludge system. The environmental behavior of emerging contaminants of microplastics (MPs), antibiotics and antibiotic resistance genes (ARGs) in the leachate activated sludge system has been monitored and analyzed comprehensively. The results suggested that MPs could effectively alter the migration trajectory of tetracycline resistance genes (tet genes) in the leachate activated sludge system under intermittent and continuous influent conditions. After adding MPs, the total average abundance of tet genes in leachate increased from 0.74 ± 0.07 to 0.78 ± 0.07 (log(10)tet genes/log(10) 16S rRNA) and that in sludge increased from 0.65 ± 0.08 to 0.70 ± 0.06 (log(10)tet genes/log(10) 16S rRNA). Except for tetA, the abundance of tetB, tetO, tetM and tetQ on MPs increased with increasing TC concentration under both aerobic and anaerobic conditions. MPs not only significantly affect the abundance level and migration trajectory of ARGs in the leachate activated sludge system, but also remarkably improve the level of heavy metals in the ambient environment, indirectly promoting the selective effect of antibiotic-resistant bacteria (ARB) and promoting the development of antibiotic resistance (AR). In addition, MPs changed their physicochemical properties and released hazardous substances with aging to force tet genes to migrate from the leachate activated sludge system to the MPs, making AR more difficult to eliminate and persisted in wastewater treatment plants. Meanwhile, microorganisms played a driving role, making MPs serve as a niche for ARGs and ARB colonization. The co-occurrence network analysis indicated the specific distribution pattern of tet genes and microorganisms in different media, and the potential host was speculated. This study improves the understanding of the environmental behavior of emerging contaminants in leachate activated sludge system and lays a theoretical for protecting the ecological environment.202337321316
755950.9998Fate of antibiotic resistance genes and resistant bacteria under various operating temperatures of sludge anaerobic digestion. This study investigates the impact of varying temperatures on reducing antibiotic resistance genes (ARGs) during anaerobic digestion (AD) of mixed raw sludge in wastewater treatment plants. Employing three different operating temperatures, i.e., 37, 55, and 65 °C, the research aims to identify how these conditions affect the diminution of resistant genes. The results, based on quantitative PCR analysis and metagenomic sequencing, show that higher temperatures significantly enhance the reduction of ARGs, with the most substantial decreases observed at 65 °C. This temperature-dependent reduction correlates with changes in the microbial community structure, where specific bacterial genera like Alicycliphilus, Macellibacteroides, Dokdonella, Ahniella, Thauera, and Zoogloea associated with ARGs exhibit decreased abundance at elevated temperatures. The study infers that AD at higher temperatures could be a more effective strategy in mitigating the spread of antibiotic resistance in the environment, suggesting a pivotal role of operational temperature in optimizing wastewater treatment processes for ARGs attenuation. The findings highlight the need for further research to refine AD protocols, aiming to minimize the environmental impact of antibiotic resistance dissemination.202540662898
754960.9998Fate of antibiotic resistance genes during sludge anaerobic fermentation: Roles of different sludge pretreatment. Excess sludge, the primary by-product of wastewater treatment plants, is the source and sink of antibiotic resistance genes (ARGs). Sludge pretreatments are an indispensable pathway to improve the resource recovery and harmfulness for anaerobic digestion sludge. However, fewer studies have compared the effects of different pretreatment technologies on the distribution of ARGs during anaerobic sludge digestion. Here, this study established seven anaerobic digesters, and four typical ARGs and one integrase gene of class 1 integron (intI1) regarded as the representative mobile genetic elements (MGEs) were examined during the whole anaerobic digestion process. It was found anaerobic digestion could effectively remove ARGs with about 70.86% removal rate of total ARGs. Among these pretreatments, the reduce efficiency of ARGs was the highest in 50 °C pretreatment, followed by oxidant, and the last was acid-alkaline. The microbial community analysis demonstrated the microbial community structure, including ARGs hosts and antibiotic resistant bacteria, was significantly changed and influenced by high temperature pretreatment. In addition, high temperature and K(2)S(2)O(8) observably decrease the level of ROS production. Macro transcriptome analysis indicated that sludge pretreatment, except for 50 °C pretreatment, up-regulated the genes relevant to lyases and transferase, but down-regulated the genes responsible for peroxidase, antioxidant enzymes and T4SS gene. This study emphasized and compared the different sludge pretreatments on the fate of ARGs in anaerobic sludge, and highlighted concerns regarding the environmental and health risks to our society.202439393457
755070.9998Evaluating the effects of activated carbon on methane generation and the fate of antibiotic resistant genes and class I integrons during anaerobic digestion of solid organic wastes. The effects of activated carbon (AC) on methane production and the fate of antibiotic resistance genes (ARGs) were evaluated through comparing the anaerobic digestion performance and transformation of ARGs among anaerobic mono-digestion of food waste, co-digestion of food waste and chicken manure, and co-digestion of food waste and waste activated sludge. Results showed that adding AC in anaerobic digesters improved methane yield by at least double through the enrichment of bacteria and archaea. Conventional digestion process showed ability in removing certain types of ARGs, such as tetA, tetX, sul1, sul2, cmlA, floR, and intl1. Supplementing AC in anaerobic digester enhanced the removal of most of the ARGs in mono-digestion of food waste. The effects tended to be minimal in co-digestion of co-substrates such as chicken manure and waste activated sludge, both of which contain a certain amount of antibiotics.201829096147
754580.9998Sulfidated nanoscale zero-valent iron is an efficient material for the removal and regrowth inhibition of antibiotic resistance genes. Antibiotic resistance genes (ARGs) and mobile gene elements (MGEs), the emerging genetic contaminants, are regarded as severe risks to public health for impairing the inactivation efficacy of antibiotics. Secondary effluents from wastewater treatment plants are the hotspots for spreading these menaces. Herein, sulfidated nanoscale zero-valent iron (S-nZVI) was occupied to remove ARGs and MGEs in secondary effluents and weaken the regrowth capacity of their bacterial carriers. The effects of S/Fe molar ratios (S/Fe), initial pH and dosages on 16S rRNA and ARGs removal were also investigated. Characterization, mass balance and scavenging experiments were conducted to explore the mechanisms of the gene removal. Quantitative PCR (qPCR) and high throughput fluorescence qPCR showed more than 3 log unit of 16S rRNA and seven out of 10 ARGs existed in secondary effluent could be removed after S-nZVI treatment. The mechanisms might be that DNA accepted the electron provided by the Fe(0) core of S-nZVI after being adsorbed onto S-nZVI surface, causing the decrease of 16S rRNA, ARGs and lost their regrowth capacity, especially for typical MGE (intI1) and further inhibiting the vertical gene transfer (VGT) and intI1-induced horizontal gene transfer (HGT). Fe(0) core was oxidized to iron oxides and hydroxides at the same time. High throughput sequencing, network analysis and variation partitioning analysis revealed the complex correlations between bacteria and ARGs in secondary effluent, S/Fe could directly influence ARGs variations, and bacterial genera made the greatest contribution to ARGs variations, followed by MGEs and operational parameters. As a result, S-nZVI could be an available reductive approach to deal with bacteria and ARGs.202032283399
754690.9998Reduction of antibiotic resistance genes under different conditions during composting process of aerobic combined with anaerobic. Single aerobic or anaerobic composting is reportedly as inefficient for removing antibiotic resistance genes (ARGs) from animal manure. This study investigates the effects of ARG removal during aerobic combined with anaerobic composting (ACA) under different conditions. The results showed that a turning frequency of once a day, the proportion of swine manure and corn straw (3:1) and an anaerobic time of 6 days were the best operating conditions for ARG reduction (>95%, especially ermF: 99.78%) during ACA. Moreover, redundancy analysis demonstrated that the bacterial community (especially Truepera, Petrimonas and Ureibacillus) had a stronger effect on ARG removal than environmental factors did (especially temperature, total phosphorus, ammonia nitrogen and pH). Network analysis indicated the important effect of these potential host bacteria on the spread of ARGs through significant co-occurrence between individual ARGs and specific bacteria. These findings offer an effective technology to reduce and block ARGs spread from animal manure.202133493747
8006100.9998Removal of antibiotic resistant bacteria and antibiotic resistance genes in wastewater effluent by UV-activated persulfate. The emerging antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are increasingly appreciated to be as important as microbial contaminants. This paper focused on UV-activated persulfate (UV/PS), an advanced oxidation process, in removing ARB and ARGs from secondary wastewater effluent. Results showed that the inactivation efficiency of macrolides-resistant bacteria (MRB), sulfonamides-resistant bacteria (SRB), tetracyclines-resistant bacteria (TRB) and quinolones-resistant bacteria (QRB) by UV/PS reached 96.6 %, 94.7 %, 98.0 % and 99.9 % in 10 min, respectively. UV/PS also showed significant removal efficiency on ARGs. The reduction of total ARGs reached 3.84 orders of magnitude in UV/PS which is more than that in UV by 0.56 log. Particularly, the removal of mobile genetic elements (MGE) which might favor the horizontal gene transfer of ARGs among different microbial achieved 76.09 % by UV/PS. High-throughput sequencing revealed that UV/PS changed the microbial community. The proportions of Proteobacteria and Actinobacteria that pose human health risks were 4.25 % and 1.6 % less than UV, respectively. Co-occurrence analyzes indicated that ARGs were differentially contributed by bacterial taxa. In UV/PS system, hydroxyl radical and sulfate radical contributed to the removal of bacteria and ARGs. Our study provided a new method of UV/PS to remove ARGs and ARB for wastewater treatment.202031954307
8086110.9998Biofilm enhanced the mitigations of antibiotics and resistome in sulfadiazine and trimethoprim co-contaminated soils. Reducing antibiotic levels in soil ecosystems is vital to curb the dissemination of antimicrobial resistance genes (ARGs) and mitigate global health threats. However, gaps persist in understanding how antibiotic resistome can be suppressed during antibiotic degradation. Herein, we investigate the efficacy of a biochar biofilm incorporating antibiotics-degrading bacterial strain (Arthrobacter sp. D2) to mitigate antibiotic resistome in non-manured and manure-amended soils with sulfadiazine (SDZ) and trimethoprim (TMP) contamination. Results show that biofilm enhanced SDZ degradation by 83.0% within three days and increased TMP attenuation by 55.4% over 60 days in non-manured soils. In the non-manured black soil, the relative abundance of ARGs increased initially after biofilm inoculation. However, by day 30, it decreased by 20.5% compared to the controls. Moreover, after 7 days, biofilm reduced TMP by 38.5% in manured soils and decreased the total ARG abundance by 19.0%. Thus, while SDZ degradation did not increase sulfonamide resistance genes, TMP dissipation led to a proliferation of insertion sequences and related TMP resistance genes. This study underscores the importance of antibiotic degradation in reducing related ARGs while cautioning against the potential proliferation and various ARGs transfer by resistant microorganisms.202439255667
7551120.9998Microbial community evolution and fate of antibiotic resistance genes during sludge treatment in two full-scale anaerobic digestion plants with thermal hydrolysis pretreatment. Anaerobic digestion (AD) with thermal hydrolysis pretreatment is widely used as an efficient sludge treatment nowadays. However, the evolution of microbial community (especially for the archaea community), the fate of antibiotic resistance genes (ARGs), and their associations during such process in full-scale sludge treatment plants are rarely reported. Therefore, these scientific questions were explored at two full-scale sludge treatment plants through high-throughput sequencing and quantitative PCR. Results showed that Methanobacterium and Methanosphaera were the dominant archaea in thermal hydrolyzed sludge. The predominant bacteria in the sludge first shifted from nutrients removal functional bacteria to spore-forming bacteria after thermal hydrolysis, and then shifted to fermentative bacteria after AD. The full-scale plants could select ermB, ermF, mefA/E, qnrS and tetM. Though the bacteria and archaea biomass and community largely influenced the fate of ARGs, multiple linear regression analysis showed that the total ARGs were mainly affected by mobile genetic elements (MGEs).201931158777
7032130.9998Free 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
7543140.9998Aerobic granular sludge for swine wastewater treatment: Implications for antibiotic and antibiotic resistance gene elimination. Swine wastewater (SW) contains high levels of traditional pollutants, antibiotics, and antibiotic resistance genes (ARGs), necessitating effective elimination. Two parallel aerobic granular sludge (AGS) reactors, R(1) and R(2), were constructed and optimized for treating SW from two pig farms, identified as SW(1) and SW(2). R(2) showed higher antibiotic removal efficiency, particularly in the removal of sulfonamides, while fluoroquinolones tended to adsorb onto the sludge. Process optimization by introducing an additional anoxic phase enhanced denitrification and reduced effluent ARG levels, also aiding in the improved removal of fluoroquinolones. The nitrite-oxidizing bacteria (NOB) Nitrospira accumulated after the treatment process, reaching 12.8 % in R(1) and 14.1 % in R(2), respectively. Mantel's test revealed that pH, NH(4)(+)-N, and Mg significantly affected ARGs and microbial community. Sulfadiazine and sulfamethazine were found to significantly impact ARGs and the microbial communities. This study provides innovative insights into the application of AGS for the treatment of real SW.202439153702
7560150.9998The effect of bacterial functional characteristics on the spread of antibiotic resistance genes in Expanded Granular Sludge Bed reactor treating the antibiotic wastewater. To explore the fate and spreading mechanism of antibiotics resistance genes (ARGs) in antibiotics wastewater system, a laboratory-scale (1.47 L) Expanded Granular Sludge Bed (EGSB) bioreactor was implemented. The operating parameters temperature (T) and hydraulic retention time (HRT) were mainly considered. This result showed the removal of ARGs and COD was asynchronous, and the recovery speed of ARGs removal was slower than that COD removal. The decreasing T was attributed to the high growth rate of ARGs host bacteria, while the shortened HRT could promote the horizontal and vertical gene transfer of ARGs in the sludge. The analysis result of potential bacterial host showed more than half of the potential host bacteria carried 2 or more ARGs and suggested an indirect mechanism of co-selection of multiple ARGs. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) was used to investigate the functional characteristics of bacterial community. This result showed the bacterial functional genes contributed 40.41% to the abundance change of ARGs in the sludge, which was higher that of bacterial community. And the function genes of "aromatic hydrocarbon degradation", "Replication, recombination and repair proteins" and "Flagellar assembly" were mainly correlated with the transfer of ARGs in the sludge. This study further revealed the mechanism of ARGs spread in the EGSB system, which would provide new ideas for the development of ARGs reduction technology.202134488144
7901160.9998Responses of antibiotic resistance genes and microbial community in the microalgae-bacteria system under sulfadiazine: Mechanisms and implications. Microalgae-bacteria system is an emerging alternative for sustainable wastewater treatment. Exploring the structure and diversity of microbial community in microalgae-bacteria system under sulfadiazine stress can contribute to the understanding of the sulfadiazine behavior in environments. Furthermore, as important carriers of antibiotic resistance genes (ARGs), microalgae can influence the profiles of ARGs either directly or indirectly through the secretion of metabolites. However, the effects of sulfadiazine on ARGs dissemination of microalgae-bacteria systems remain underreported. Herein, the impacts of sulfadiazine (1 mg/L) on the structural diversity and metabolic activity of microorganisms were examined in microalgae-bacteria systems. Results showed that microalgae-bacteria system could remove NH(4)(+)-N better (about 72.3 %) than activated sludge system, and hydrolysis was the first step in sulfadiazine degradation. A high level of intI1 (5.7 × 10(4) copies/mL) was detected in the initial media of the microalgae-bacteria system. Microalgae could hamper the rate of horizontal gene transfer activation. Compared with activated sludge system, the abundance of sul genes (sul1, sul2, sul3, and sulA) was significantly lowered after treating with microalgae-bacteria system. Additionally, the number of proteins and the sum of polysaccharides in the extracellular polymeric substances of the activated sludge system were lower than those of the microalgae-bacteria system. Microalgae can alter microbial communities. The genus Rozellomycota predominated all samples. Fungi with relatively high abundance increased in the microalgae-bacteria system, including Dipodascaceae, Rhodotorula, and Geotrichum. These results offer valuable insights into the application processes involving microalgae-bacteria system.202540602895
7548170.9998Maturity phase is crucial for removing antibiotic resistance genes during composting: novel insights into dissolved organic matter-microbial symbiosis system. Composting is widely regarded as an effective method for reducing antibiotic resistance genes (ARGs) in livestock and poultry manure. However, the critical mechanisms of ARGs in different composting phase are still unclear. In this study, normal composting and two types of rapid composting (without mature phase) were used to analyze the removal of ARGs and the succession of dissolved organic matter (DOM). Compared to normal composting, rapid composting reactivated tetracyclines, sulfonamide, and quinolones resistance genes during the maturation phase and reduced the total ARGs removal rates by 45.58 %-57.87 %. Humus-like components could inhibit the proliferation of ARGs, and the enrichment of protein-like components increased abundances of Pusillimonas, Persicitalea, and Pseudomonas, indirectly reducing the removal. This study is the first to demonstrate the contribution of DOM and microbial community to ARGs removal, emphasizing the importance of the maturation phase for ARGs elimination. This research provides guidance for producing safe compost products.202540311709
7542180.9998Antibiotics resistance removal from piggery wastewater by an integrated anaerobic-aerobic biofilm reactor: Efficiency and mechanism. Antibiotic resistance residual in piggery wastewater poses serious threat to environment and human health. Biological treatment process is commonly installed to remove nutrient from piggery wastewater and also effective in removing antibiotics to varying degrees. But the specific pathways and mechanisms involved in the removal of antibiotic resistance are not yet well-understood. An integrated anaerobic-aerobic biofilm reactor (IAOBR) has been demonstrated efficient in removing conventional nutrients. It is here shown that the IAOBR effectively removed 79.0% of Sulfonamides, 55.7% of Tetracyclines and 53.6% of Quinones. Antibiotic resistance bacteria (ARB) were simultaneously inactivated by ~0.5 logs. Antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) were decreased by 0.51 logs and 0.42 logs, respectively. The antibiotics were mainly removed through aerobic compartments of the IAOBR. The mass loss of antibiotics in the reactor was achieved by biodegradation and adsorption, accounting for 52.1% and 47.9%, respectively. An obvious accumulation of ARGs was observed in the activated sludge. The potential host of ARGs was analyzed via microbial community and network. Partial least squares-structural equation model and correlation analysis revealed that the enrichment of ARGs was positively affected by MGEs, followed by bacterial community and ARBs, but the effect of antibiotics on ARGs was negative. Outcomes of this study provide valuable insights into the mechanisms of antibiotic resistance removal in biological treatment processes.202337714352
8578190.9998Impact of earthworms on suppressing dissemination of antibiotic resistance genes during vermicomposting treatment of excess sludge. Earthworms play a crucial role in suppressing the dissemination of antibiotic resistance genes (ARGs) during vermicomposting. However, there is still a lack of how earthworms influence the spread of ARGs. To address this gap, a microcosm experiment was conducted, incorporating earthworms and utilizing metagenomics and quantitative PCR to assess the impact of earthworms on microbial interactions and the removal of plasmid-induced ARGs. The findings revealed that vermicomposting led to a reduction in the relative abundance of ARGs by altering microbial communities and interactions. Significantly, vermicomposting demonstrated an impressive capability, reducing 92% of ARGs donor bacteria and impeding the transmission of 94% of the RP4 plasmid. Furthermore, through structural equation model analysis, it was determined that mobile genetic elements and environmental variables were the primary influencers of ARG reduction. Overall, this study offers a fresh perspective on the effects of vermicomposting and its potential to mitigate the spread of ARGs.202438885722