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792600.9929Microplastics Exacerbated Conjugative Transfer of Antibiotic Resistance Genes during Ultraviolet Disinfection: Highlighting Difference between Conventional and Biodegradable Ones. Microplastics (MPs) have been confirmed as a hotspot for antibiotic resistance genes (ARGs) in wastewater. However, the impact of MPs on the transfer of ARGs in wastewater treatment remains unclear. This study investigated the roles and mechanisms of conventional (polystyrene, PS) and biodegradable (polylactic acid, PLA) MPs in the conjugative transfer of ARGs during ultraviolet disinfection. The results showed that MPs significantly facilitated the conjugative transfer of ARGs compared with individual ultraviolet disinfection, and PSMPs exhibited higher facilitation than PLAMPs. The facilitation effects were attributed to light shielding and the production of reactive oxygen species (ROS) and nanoplastics from ultraviolet irradiation of MPs. The light shielding of MPs protected the bacteria and ARGs from ultraviolet inactivation. More importantly, ROS and nanoplastics generated from irradiated MPs induced intracellular oxidative stress on bacteria and further increased the cell membrane permeability and intercellular contact, ultimately enhancing the ARG exchange. The greater fragmentation of PSMPs than PLAMPs resulted in a higher intracellular oxidative stress and a stronger enhancement. This study highlights the concerns of conventional and biodegradable MPs associated with the transfer of ARGs during wastewater treatment, which provides new insights into the combined risks of MPs and ARGs in the environment.202539723446
794010.9925Microplastics affect the ammonia oxidation performance of aerobic granular sludge and enrich the intracellular and extracellular antibiotic resistance genes. Microplastics (MPs) and antibiotic resistance genes (ARGs), as emerging pollutants, are frequently detected in wastewater treatment plants, and their threats to the environment have received extensive attentions. However, the effects of MPs on the nitrification of aerobic granular sludge (AGS) and the spread patterns of intracellular and extracellular ARGs (iARGs and eARGs) in AGS were still unknown. In this study, the responses of AGS to the exposure of 1, 10 and 100 mg/L of typical MPs (polyvinyl chloride (PVC), polyamide (PA), polystyrene (PS) and polyethylene (PE)) and tetracycline were focused on in 3 L nitrifying sequencing batch reactors. 10 mg/L MPs decreased the nitrification function, but nitrification could recover. Furthermore, MPs inhibited ammonia-oxidizing bacteria and enriched nitrite-oxidizing bacteria, leading partial nitrification to losing stability. PVC, PA and PS stimulated the secretion of extracellular polymeric substances and reactive oxygen species. PE had less negative effect on AGS than PVC, PA and PS. The abundances of iARGs and eARGs (tetW, tetE and intI1) increased significantly and the intracellular and extracellular microbial communities obviously shifted in AGS system under MPs stress. Potential pathogenic bacteria might be the common hosts of iARGs and eARGs in AGS system and were enriched in AGS and MPs biofilms.202133387747
812320.9923The effect of bulk-biochar and nano-biochar amendment on the removal of antibiotic resistance genes in microplastic contaminated soil. Biochar amendment has significant benefits in removing antibiotic resistance genes (ARGs) in the soil. Nevertheless, there is little information on ARGs removal in microplastic contaminated soil. Herein, a 42-day soil microcosm experiment were carried out to study how two coconut shell biochars (bulk- and nano-size) eliminate soil ARGs with/without microplastic presence. The results showed that microplastic increased significantly the numbers and abundances of ARGs in soil at 14d of cultivation. And, two biochars amendment effectively inhibited soil ARGs spread whether or not microplastic was present, especially for nano-biochar which had more effective removal compared to bulk-biochar. However, microplastic weakened soil ARGs removal after applying same biochar. Two biochars removed ARGs through decreasing horizontal gene transfer (HGT) of ARGs, potential host-bacteria abundances, some bacteria crowding the eco-niche of hosts and promoting soil properties. The adverse effect of microplastic on ARGs removal was mainly caused by weakening mobile genetic elements (MGEs) removal, and by changing soil properties. Structural equation modeling (SEM) analysis indicated that biochar's effect on ARGs profile was changed by its size and microplastic presence through altering MGEs abundances. These results highlight that biochar amendment is still an effective method for ARGs removal in microplastic contaminated soil.202437907163
811130.9922Effect of alkaline-thermal pretreatment on biodegradable plastics degradation and dissemination of antibiotic resistance genes in co-compost system. Biodegradable plastics (BDPs) are an eco-friendly alternative to traditional plastics in organic waste, but their microbial degradation and impact on antibiotic resistance genes (ARGs) transmission during co-composting remain poorly understood. This study examines how alkaline-thermal pretreatment enhances BDPs degradation and influences the fate of ARGs and mobile genetic elements (MGEs) in co-composting. Pretreatment with 0.1 mol/L NaOH at 100℃ for 40 minutes increased the surface roughness and hydrophilicity of BDPs while reducing their molecular weight and thermal stability. Incorporating pretreated BDPs film (8 g/kg-TS) into the compost reduced the molecular weight of the BDPs by 59.70 % during the maturation stage, facilitating compost heating and prolonging the thermophilic stage. However, incomplete degradation of BDPs releases numerous smaller-sized microplastics, which can act as carriers for microorganisms, facilitating the dissemination of ARGs across environments and posing significant ecological and public health risks. Metagenomic analysis revealed that pretreatment enriched plastic-degrading bacteria, such as Thermobifida fusca, on BDPs surfaces and accelerated microbial plastic degradation during the thermophilic stage, but also increased ARGs abundance. Although pretreatment significantly reduced MGEs abundance (tnpA, IS19), the risk of ARGs dissemination remained. Three plastic-degrading bacteria (Pigmentiphaga sp002188465, Bacillus clausii, and Bacillus altitudinis) were identified as ARGs hosts, underscoring the need to address the risk of horizontal gene transfer of ARGs associated with pretreatment in organic waste management.202539970645
792740.9921Different microplastics distinctively enriched the antibiotic resistance genes in anaerobic sludge digestion through shifting specific hosts and promoting horizontal gene flow. Both microplastics (MPs) and antibiotic resistance genes (ARGs) are intensively detected in waste activated sludge (WAS). However, the distinctive impacts of different MPs on ARGs emergence, dissemination, and its potential mechanisms remain unclear. In this study, long-term semi-continuous digesters were performed to examine the profiles of ARGs and antibiotic-resistant bacteria (ARB) in response to two different typical MPs (polyethylene (PE) and polyvinyl chloride (PVC)) in anaerobic sludge digestion. Metagenomic results show that PE- and PVC-MPs increase ARGs abundance by 14.8% and 23.6% in digester, respectively. ARB are also enriched by PE- and PVC-MPs, Acinetobacter sp. and Salmonella sp. are the dominant ARB. Further exploration reveals that PVC-MPs stimulates the acquisition of ARGs by human pathogen bacteria (HPB) and functional microorganisms (FMs), but PE-MPs doesn't. Network analysis shows that more ARGs tend to co-occur with HBP and FMs after MPs exposure, and more importantly, new bacteria are observed to acquire ARGs possibly via horizontal gene flow (HGF) in MPs-stressed digester. The genes involved in the HGF process, including reactive oxygen species (ROS) production, cell membrane permeability, extracellular polymeric substances (EPS) secretion, and ATP synthesis, are also enhanced by MPs, thereby attributing to the promoted ARGs dissemination. These findings offer advanced insights into the distinctive contribution of MPs to fate, host, dissemination of ARGs in anaerobic sludge digestion.202336423550
693850.9920Assessment of the Effects of Biodegradable and Nonbiodegradable Microplastics Combined with Pesticides on the Soil Microbiota. Microplastics (MPs) and pesticides pose significant threats to the health of soil ecosystems. This study investigated the individual and combined effects of biodegradable polylactic acid (PLA) and nonbiodegradable polyethylene terephthalate (PET) microplastics alongside glyphosate and imidacloprid pesticides on soil microbial communities and antibiotic resistance genes (ARGs) via microcosm experiments. Compared with the control, PLA significantly increased microbial alpha diversity and enhanced microbial functions related to environmental information processing and metabolism. However, PLA also selectively enriched populations of beneficial and potentially pathogenic bacteria, whereas PET had comparatively weaker effects. Crucially, PLA exposure resulted in substantially higher total abundance and ecological risk levels of soil ARGs than did PET. Coexposure with pesticides further amplified these effects, with PLA demonstrating notable synergistic interactions with both glyphosate and imidacloprid. These findings challenge the conventional assumption that biodegradable MPs such as PLA are environmentally safer than nonbiodegradable MPs, thus highlighting their potential to induce more complex and potentially severe ecological risks under co-contamination scenarios with pesticides.202541175058
792860.9919Insight into the responses of antibiotic resistance genes in microplastic biofilms to zinc oxide nanoparticles and zinc ions pressures in landfill leachate. Microplastic (MP) biofilms are hotspots of antibiotic resistance genes (ARGs) in landfill environment. MP biofilms in landfill leachate coexist with heavy metals and metallic nanoparticles (NPs) that considered to be the selective agents of ARGs. However, the effects of these selective pressures on ARGs in MP biofilms and their differences in MP-surrounding leachate have not been well understood. Herein, the changes of ARG abundances in MP biofilms and corresponding leachate under zinc oxide (ZnO) NPs and zinc ion (Zn(2+)) pressures were comparatively analyzed. The presence of ZnO NPs and Zn(2+) promoted the enrichment of ARGs in MP biofilms, and the enrichment was more pronounced in ZnO NPs groups. ZnO NPs and especially Zn(2+) mainly decreased the abundances of ARGs in leachate. The increase of integron abundances and reactive oxygen species production in MP biofilms implied the enhanced potential for horizontal transfer of ARGs under ZnO NPs and Zn(2+) pressures. Meanwhile, the co-occurrence pattern between ARGs and bacterial genera in MP biofilms with more diverse potential ARG hosts was more complex than in leachate, and the enrichment of ARG-hosting bacteria in MP biofilms under ZnO NPs and Zn(2+) pressures supported the enrichment of ARGs.202337480611
788770.9918Double-edged sword effects of sulfate reduction process in sulfur autotrophic denitrification system: Accelerating nitrogen removal and promoting antibiotic resistance genes spread. This study proposed the double-edged sword effects of sulfate reduction process on nitrogen removal and antibiotic resistance genes (ARGs) transmission in sulfur autotrophic denitrification system. Excitation-emission matrix-parallel factor analysis identified the protein-like fraction in soluble microbial products as main endogenous organic matter driving the sulfate reduction process. The resultant sulfide tended to serve as bacterial modulators, augmenting electron transfer processes and mitigating oxidative stress, thereby enhancing sulfur oxidizing bacteria (SOB) activity, rather than extra electron donors. The cooperation between SOB and heterotroph (sulfate reducing bacteria (SRB) and heterotrophic denitrification bacteria (HDB)) were responsible for advanced nitrogen removal, facilitated by multiple metabolic pathways including denitrification, sulfur oxidation, and sulfate reduction. However, SRB and HDB were potential ARGs hosts and assimilatory sulfate reduction pathway positively contributed to ARGs spread. Overall, the sulfate reduction process in sulfur autotrophic denitrification system boosted nitrogen removal process, but also increased the risk of ARGs transmission.202439122125
793580.9917Removal of antibiotic resistance genes by Cl(2)-UV process: Direct UV damage outweighs free radicals in effectiveness. Antibiotic resistance genes (ARGs) pose significant environmental health problems and have become a major global concern. This study investigated the efficacy and mechanism of the Cl(2)-UV process (chlorine followed by UV irradiation) for removing ARGs in various forms. The Cl(2)-UV process caused irreversible damage to nearly all ARB at typical disinfectant dosages. In solutions containing only extracellular ARGs (eARGs), the Cl₂-UV process achieved over 99.0 % degradation of eARGs. When both eARGs and intracellular ARGs (iARGs) were present, the process reached a 97.2 % removal rate for iARGs. While the abundance of eARGs initially increased due to the release of iARGs from lysed cells during pre-chlorination, subsequent UV irradiation rapidly degraded the released eARGs, restoring their abundance to near-initial levels by the end of the Cl₂-UV process. Analysis of the roles in degrading eARGs and iARGs during the Cl(2)-UV process revealed that UV, rather than free radicals, was the dominant factor causing ARG damage. Pre-chlorination enhanced direct UV damage to eARGs and iARGs by altering plasmid conformation and promoting efficient damage to high UV-absorbing cellular components. Furthermore, no further natural transformation of residual ARGs occurred following the Cl(2)-UV treatment. This study demonstrated strong evidence for the effectiveness of the Cl(2)-UV process in controlling antibiotic resistance.202540048777
812490.9917Effect of graphene and graphene oxide on antibiotic resistance genes during copper-contained swine manure anaerobic digestion. Copper is an important selectors for antibiotic resistance genes (ARGs) transfer because of metal-antibiotic cross-resistance and/or coresistance. Due to carbon-based materials' good adsorption capacity for heavy metals, graphene and graphene oxide have great potential to reduce ARGs abundance in the environment with copper pollution. To figure out the mechanics, this study investigated the effects of graphene and graphene oxide on the succession of ARGs, mobile genetic elements (MGEs), heavy metal resistance genes (HMRGs), and bacterial communities during copper-contained swine manure anaerobic digestion. Results showed that graphene and graphene oxide could reduce ARGs abundance in varying degrees with the anaerobic reactors that contained a higher concentration of copper. Nevertheless, graphene decreased the abundance of ARGs more effectively than graphene oxide. Phylum-level bacteria such as Firmicutes, Bacteroidetes, Spirochaetes, and Verrucomicrobiaat were significantly positively correlated with most ARGs. Network and redundancy analyses demonstrated that alterations in the bacterial community are one of the main factors leading to the changes in ARGs. Firmicutes, Bacteroidetes, and Spirochaetes were enriched lower in graphene reactor than graphene oxide in anaerobic digestion products, which may be the main reason that graphene is superior to graphene oxide in reduced ARGs abundance. Additionally, ARGs were close to HMRGs than MGEs in the treatments with graphene, the opposite in graphene oxide reactors. Therefore, we speculate that the reduction of HMRGs in graphene may contribute to the result that graphene is superior to graphene oxide in reduced ARGs abundance in anaerobic digestion.202336394812
7873100.9915Wheat straw pyrochar more efficiently decreased enantioselective uptake of dinotefuran by lettuce and dissemination of antibiotic resistance genes than hydrochar in an agricultural soil. Remediation of soils pollution caused by dinotefuran, a chiral pesticide, is indispensable for ensuring human food security. In comparison with pyrochar, the effect of hydrochar on enantioselective fate of dinotefuran, and antibiotic resistance genes (ARGs) profiles in the contaminated soils remain poorly understood. Therefore, wheat straw hydrochar (SHC) and pyrochar (SPC) were prepared at 220 and 500 °C, respectively, to investigate their effects and underlying mechanisms on enantioselective fate of dinotefuran enantiomers and metabolites, and soil ARG abundance in soil-plant ecosystems using a 30-day pot experiment planted with lettuce. SPC showed a greater reduction effect on the accumulation of R- and S-dinotefuran and metabolites in lettuce shoots than SHC. This was mainly resulted from the lowered soil bioavailability of R- and S-dinotefuran due to adsorption/immobilization by chars, together with the char-enhanced pesticide-degrading bacteria resulted from increased soil pH and organic matter content. Both SPC and SHC efficiently reduced ARG levels in soils, owing to lowered abundance of ARG-carrying bacteria and declined horizontal gene transfer induced by decreased dinotefuran bioavailability. The above results provide new insights for optimizing char-based sustainable technologies to mitigate pollution of dinotefuran and spread of ARGs in agroecosystems.202336996986
8580110.9915Mitigation of microplastic-associated emerging pollutants by chlorination using field-collected microplastic: Antimicrobial-resistant genes and pathogens. The ubiquity of microplastics (MPs) in aquatic environments has raised significant concerns regarding their roles as vectors for antibiotic-resistance genes (ARGs) and antibiotic-resistant pathogens (ARPs). This study investigated the mitigation of ARGs and ARPs associated with field-collected MPs through chlorination using free available chlorine (FAC) at varying concentrations. FAC effectively reduced the absolute abundance of ARGs on MPs by up to 99.69 %, although the relative abundance of certain ARGs persisted or increased after treatments. Results revealed that the three-dimensional structure of biofilms on MPs significantly influenced FAC efficacy, with interior biofilm bacteria demonstrating greater resistance than outer biofilm. Additionally, FAC induced fragmentation of MPs, particularly increasing the proportion of particles smaller than 100 μm. Notably, ARGs such as sul1 and ermB showed substantial reductions in absolute abundance, whereas ermC and sul2 exhibited less reduction, highlighting the complexity of disinfection in MP-associated biofilms. These findings underscore the need for optimizing disinfection strategies to mitigate ARG dissemination and address environmental risks posed by MPs in wastewater effluents.202540436100
7930120.9915Fates of extracellular and intracellular antibiotic resistance genes in activated sludge and plastisphere under sulfadiazine pressure. Microplastics, antibiotics, and antibiotic resistance genes (ARGs) represent prominent emerging contaminants that can potentially hinder the efficacy of biological wastewater treatment and pose health risks. Plastisphere as a distinct ecological niche for microorganisms, acts as a repository for ARGs and potential pathogenic bacteria. Nonetheless, the spread pattern of extracellular ARGs (eARGs) and intracellular ARGs (iARGs) in plastisphere under antibiotic exposure was not yet known. This study aimed to investigate disparities in extracellular polymeric substances (EPS) production, extracellular and intracellular microbial community structures, as well as the transmission of eARGs and iARGs between activated sludge and plastisphere in an anaerobic/anoxic/oxic system under sulfadiazine (SDZ) exposure. SDZ was found to enhance EPS production in activated sludge and plastisphere. Interestingly, as SDZ removal efficiency increased, EPS content decreased in activated sludge and plastisphere collected from oxic zone, and continued to increase in plastisphere samples collected from anaerobic and anoxic zones. There were significant differences in microbial community structure between activated sludge and plastisphere, and the DNA fragments of potential pathogenic bacteria were detected in extracellular samples. SDZ exhibited a promoting effect on the propagation of eARGs, which were more abundant in the plastisphere than in activated sludge, thus heightening the risk of ARGs dissemination. Extracellular mobile genetic elements played a pivotal role in driving the spread of eARGs, while the microbial community induced the changes of iARGs. Potential pathogenic bacteria emerged as potential hosts for ARGs and mobile genetic elements within activated sludge and plastisphere, leading to more serious environmental threats.202337898001
7929130.9914Size-dependent effects of microplastics on antibiotic resistance genes fate in wastewater treatment systems: The role of changed surface property and microbial assemblages in a continuous exposure mode. Microplastics (MPs) were continuously transported to wastewater treatment systems and accumulated in sludge constantly, potentially affecting systems function and co-occurrent contaminants fate. However, previous studies were based on acute exposure of MPs, which could not reflect the dynamics of MPs accumulation. Herein, this study firstly raised a more realistic method to evaluate the practical impacts of MPs on systems purification efficiency and antibiotic resistance genes (ARGs) fate. Continuous exposure of MPs did not pose negative effects on nutrients removal, but significantly changed the occurrence patterns of ARGs. ARGs abundances increased by 42.8 % and 54.3 % when exposed to millimeter-size MPs (mm-MPs) polyamide and polyethylene terephthalate, but increased by 31.3 % and 39.4 % to micron-size MPs (μm-MPs), respectively. Thus, mm-MPs posed severer effects on ARGs than μm-MPs. Further, mm-MPs surface properties were obviously altered after long-term exposure (higher specific surface area and O-containing species), which benefited microbes attachment. More importantly, more taxa linkages and changed topological properties (higher average degree and average weight) of co-occurrent network were observed in sludge with mm-MPs than with μm-MPs, as well as totally different potential host bacteria of ARGs. Rough surface of MPs and closer relations between ARGs and bacteria taxa contributed to the propagation of ARGs, which accounted for the observed higher ARGs abundances of mm-MPs. This study demonstrated that long-term accumulation of MPs in wastewater treatment systems affected ARGs fate, and mm-MPs caused severer risk due to their enrichment of ARGs. The results would promote the understanding of MPs real environmental behavior and influences.202236037899
8549140.9914Current perspectives on microalgae and extracellular polymers for reducing antibiotic resistance genes in livestock wastewater. Antibiotic resistance genes (ARGs) in livestock wastewater resulting from excessive antibiotics used in animal farming pose significant environmental and public health risks. Conventional treatment methods are often costly, inefficient, and may inadvertently promote ARG transmission. Microalgae, with their long genetic distance from bacteria and strong ability to utilize wastewater nutrients, offer a sustainable solution for ARG mitigation. This review studied the abundance and characterization of ARGs in livestock wastewater, highlighted microalgal-based removal mechanisms of ARGs, including phagocytosis, competition, and absorption by extracellular polymeric substances (EPS), and explored factors influencing their efficacy. Notably, the microalgae-EPS system reduced ARGs by 0.62-3.00 log, demonstrating significant potential in wastewater treatment. Key challenges, such as optimizing algal species, understanding EPS-ARG interactions, targeted reduction of host bacteria, and scaling technologies, were discussed. This work provides critical insights for advancing microalgal-based strategies for ARG removal, promoting environmentally friendly and efficient wastewater management.202540324729
7937150.9914Effects of oxytetracycline on variation in intracellular and extracellular antibiotic resistance genes during swine manure composting. This research aimed to investigate the alterations in extracellular (eARGs) and intracellular (iARGs) antibiotic resistance genes in response to oxytetracycline (OTC), and unravel the dissemination mechanism of ARGs during composting. The findings revealed both low (L-OTC) and high contents (H-OTC) of OTC significantly enhanced absolute abundance (AA) of iARGs (p < 0.05), compared to CK (no OTC). Composting proved to be a proficient strategy for removing eARGs, while AA of eARGs was significantly enhanced in H-OTC (p < 0.05). OTC resulted in an increase in AA of mobile genetic elements (MGEs), ATP levels, antioxidant and DNA repair enzymes in bacteria in compost product. Structural equation model further demonstrated that OTC promoted bacterial DNA repair and antioxidant enzyme activities, altered bacterial community and enhanced MGEs abundance, thereby facilitating iARGs dissemination. This study highlights OTC can increase eARGs and iARGs abundance, underscoring the need for appropriate countermeasures to mitigate potential hazards.202438036151
8572160.9912Enantioselective effects of chiral antibiotics on antibiotic resistance gene dissemination and risk in activated sludge. Misuse of antibiotics drives the spread of antibiotic resistance genes (ARGs). Although reducing residual antibiotic concentrations can help curb ARG proliferation, the biodegradation and transformation of antibiotic stereoisomers may exacerbate resistance development. However, the impact of antibiotic enantiomers on ARG proliferation remains poorly understood. This study employed metagenomic analysis to investigate the enantiomer-specific selection and resistance risks of chiral antibiotic ofloxacin (OFL) and its (S)-enantiomer, levofloxacin (LEV), in activated sludge. Results showed that LEV primarily promoted the enrichment of ARGs related to aminoglycoside and mupirocin resistance by selecting for pathogenic bacteria carrying virulence factors under high toxicity stress. OFL-driven ARG proliferation involved more diverse mechanisms, including increased gene mobility, co-selection with heavy metals, broader host range, and elevated pathogenicity. The antibiotic resistome risk index (ARRI) further demonstrated a higher environmental risk under OFL treatment than LEV. These findings offer critical insights into the enantioselective resistance risks posed by chiral antibiotics.202540456327
8609170.9912Nano-biochar regulates phage-host interactions, reducing antibiotic resistance genes in vermicomposting systems. Biochar amendment reshapes microbial community dynamics in vermicomposting, but the mechanism of how phages respond to this anthropogenic intervention and regulate the dissemination of antibiotic resistance genes (ARGs) remains unclear. In this study, we used metagenomics, viromics, and laboratory validation to explore how nano-biochar affects phage-host interactions and ARGs dissemination in vermicomposting. Our results revealed distinct niche-specific phage life strategies. In vermicompost, lytic phages dominated and used a "kill-the-winner" strategy to suppress antibiotic-resistant bacteria (ARB). In contrast, lysogenic phages prevailed in the earthworm gut, adopting a "piggyback-the-winner" strategy that promoted ARGs transduction through mutualistic host interactions. Nano-biochar induced the conversion of lysogenic to lytic phages in the earthworm gut, while concurrently reducing the abundance of lysogenic phages and their encoded auxiliary metabolic genes carried by ARB. This shift disrupted phage-host mutualism and inhibited ARGs transmission via a "phage shunting" mechanism. In vitro validation with batch culture experiments further confirmed that lysogenic phages increased transduction of ARGs in the earthworm gut, while nano-biochar reduced the spread of ARGs by enhancing lysis infectivity. Our study constructs a mechanistic framework linking nano-biochar induced shifts in phage lifestyles that suppress ARG spread, offering insights into phage-host coadaptation and resistance mitigation strategies in organic waste treatment ecosystems.202540838886
7855180.9912Combat against antibiotic resistance genes during photo-treatment of magnetic Zr-MOFs@Layered double hydroxide heterojunction: Conjugative transfer risk mitigating and bacterial inactivation. The dissemination of antimicrobial resistance (AMR) in wastewater treatment poses a severe threat to the global ecological environment. This study explored the effectiveness of photocatalysis in inactivating antibiotic resistant bacteria (ARB) and quantitatively clarified the inhibiting rate of the transfer of antibiotics resistance genes (ARGs). Herein, the magnetic heterojunction as UiO-66-NH(2)@CuFe LDH-Fe(3)O(4) (UN-66@LDH-Fe) effectively facilitated the electron-hole separation and accelerated the photogenerated charge transfer, thereby guaranteeing the stable practical application in aeration tanks. Notably, the internal electric field of heterogeneous photocatalyst resulted in significant increase of ARGs inactivation, achieving 5.63 log of ARB, 3.66 log of tetA and 3.57 log of Ampr genes were photodegraded under optimal reaction conditions within 6 h. Based on the complex microbial and molecular mechanism of multiple-ARB communities inactivation in photo-treatment, the photogenerated reactive oxygen species (ROSs, ·OH and ·O(2)(-)) effectively destroyed bacterial membrane protein, thereby the intracellular ROSs and redox cycles further induced oxidative stress, attributing to the abundance reduction of ARGs and their host bacteria. Moreover, long-term (7 days) continuous operation preliminarily verified the practical potential in reducing AMR spread and developing wastewater treatment efficacy. Overall, this study presented an advantageous synergistic strategy for mitigating the AMR-associated environmental risk in wastewater treatment.202540188541
7893190.9912Removal of ofloxacin and inhibition of antibiotic resistance gene spread during the aerobic biofilm treatment of rural domestic sewage through the micro-nano aeration technology. Micro-nano aeration (MNA) has great potential for emerging contaminant removal. However, the mechanism of antibiotic removal and antibiotic resistance gene (ARG) spread, and the impact of the different aeration conditions remain unclear. This study investigated the adsorption and biodegradation of ofloxacin (OFL) and the spread of ARGs in aerobic biofilm systems under MNA and conventional aeration (CVA) conditions. Results showed that the MNA increased OFL removal by 17.27 %-40.54 % and decreased total ARG abundance by 36.37 %-54.98 %, compared with CVA. MNA-induced biofilm rough morphology, high zeta potential, and reduced extracellular polymeric substance (EPS) secretion enhanced OFL adsorption. High dissolved oxygen and temperature, induced by MNA-enriched aerobic bacteria and their carrying OFL-degrading genes, enhanced OFL biodegradation. MNA inhibited the enrichment of ARG host bacteria, which acquired ARGs possibly via horizontal gene transfer (HGT). Functional profiles involved in the HGT process, including reactive oxygen species production, membrane permeability, mobile genetic elements (MGEs), adenosine triphosphate synthesis, and EPS secretion, were down-regulated by MNA, inhibiting ARG spread. Partial least-squares path modeling revealed that MGEs might be the main factor inhibiting ARG spread. This study provides insights into the mechanisms by which MNA enhances antibiotic removal and inhibits ARG spread in aerobic biofilm systems.202539733752