Elimination of representative antibiotic-resistant bacteria, antibiotic resistance genes and ciprofloxacin from water via photoactivation of periodate using FeS(2). - Related Documents




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783401.0000Elimination of representative antibiotic-resistant bacteria, antibiotic resistance genes and ciprofloxacin from water via photoactivation of periodate using FeS(2). The propagation of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) induced by the release of antibiotics poses great threats to ecological safety and human health. In this study, periodate (PI)/FeS(2)/simulated sunlight (SSL) system was employed to remove representative ARB, ARGs and antibiotics in water. 1 × 10(7) CFU mL(-1) of gentamycin-resistant Escherichia coli was effectively disinfected below limit of detection in PI/FeS(2)/SSL system under different water matrix and in real water samples. Sulfadiazine-resistant Pseudomonas and Gram-positive Bacillus subtilis could also be efficiently sterilized. Theoretical calculation showed that (110) facet was the most reactive facet on FeS(2) to activate PI for the generation of reactive species (·OH, ·O(2)(-), h(+) and Fe(IV)=O) to damage cell membrane and intracellular enzyme defense system. Both intracellular and extracellular ARGs could be degraded and the expression levels of multidrug resistance-related genes were downregulated during the disinfection process. Thus, horizontal gene transfer (HGT) of ARB was inhibited. Moreover, PI/FeS(2)/SSL system could disinfect ARB in a continuous flow reactor and in an enlarged reactor under natural sunlight irradiation. PI/FeS(2)/SSL system could also effectively degrade the HGT-promoting antibiotic (ciprofloxacin) via hydroxylation and ring cleavage process. Overall, PI/FeS(2)/SSL exhibited great promise for the elimination of antibiotic resistance from water.202438917629
783510.9996Crouching bacteria, hidden tetA genes in natural waters: Intracellular damage via double persulfate activation (UVA/Fe(2+)/PDS) effectively alleviates the spread of antibiotic resistance. In this study, we elucidated the chemical and biological inactivation mechanisms of peroxydisulfate (PDS) activated by UVA and Fe(2+) (UVA/Fe(2+)/PDS) in wild-type antibiotic-resistant bacteria (ARB) isolated from a river in Inner Mongolia. Among the screened wild-type ARB, the relative abundance of unidentified Enterobacteriaceae, Stenotrophomonas, and Ralstonia was high. A ratio of 1:1 for Fe(2+) and PDS under 18 W·m(-2) UVA radiation (sunny days) completely inactivated the environmental ARB isolates. In the macro view of the inactivation process, Fe(2+) first activates PDS rapidly, and later the UVA energy accumulated starts to activate PDS; HO• then becomes the main active species at a rate-limiting step. From a micro perspective, damage to the cell wall, intracellular proteins, inactivation of antioxidant enzymes, and genetic material degradation are the inactivation series of events by UVA/Fe(2+)/PDS, contributing to the 97.8 % inactivation of ARB at the initial stage. No regrowth of sublethal ARBs was observed. The transfer of tetracycline resistance genes from ARB to lab E. coli was evaluated by horizontal gene transfer (HGT), in which no HGT occurred when ARB was eliminated by UVA/Fe(2+)/PDS. Moreover, the sulfate and iron residuals in the effluents of treated water were lower than the drinking water standards. In summary, PDS, UVA, and Fe(2+) activation effectively inactivated wild ARB with a low concentration of reagents, while inhibiting their regrowth and spread of resistance due to the contribution of intracellular inactivation pathways.202439316921
782720.9996Inactivation of antibiotic-resistant bacteria and antibiotic resistance genes by electrochemical oxidation/electro-Fenton process. Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in the environment are of great concern due to their potential risk to human health. The effluents from wastewater treatment plants and livestock production are major sources of ARB and ARGs. Chlorination, UV irradiation, and ozone disinfection cannot remove ARGs completely. In this study, the potential of electrochemical oxidation and electro-Fenton processes as alternative treatment technologies for inactivation of ARB and ARGs in both intracellular and extracellular forms was evaluated. Results showed that the electrochemical oxidation process was effective for the inactivation of selected ARB but not for the removal of intracellular ARGs or extracellular ARGs. The electro-Fenton process was more effective for the removal of both intracellular and extracellular ARGs. The removal efficiency after 120 min of electro-Fenton treatment under 21.42 mA/cm(2) was 3.8 logs for intracellular tetA, 4.1 logs for intracellular ampC, 5.2 logs for extracellular tetA, and 4.8 logs for extracellular ampC, respectively in the presence of 1.0 mmol/L Fe(2+). It is suggested that electrochemical oxidation is an effective disinfection method for ARB and the electro-Fenton process is a promising technology for the removal of both intracellular and extracellular ARGs in wastewater.202032701499
784930.9996Efficient removal of antibiotic-resistant bacteria and intracellular antibiotic resistance genes by heterogeneous activation of peroxymonosulfate on hierarchical macro-mesoporous Co(3)O(4)-SiO(2) with enhanced photogenerated charges. Antibiotic resistance genes (ARGs) and their host antibiotic-resistant bacteria (ARB) are widely detected in the environment and pose a threat to human health. Traditional disinfection in water treatment plants cannot effectively remove ARGs and ARB. This study explored the potential of a heterogeneous photo-Fenton-like process utilizing a hierarchical macro-mesoporous Co(3)O(4)-SiO(2) (MM CS) catalyst for activation of peroxymonosulfate (PMS) to inactivate ARB and degrade the intracellular ARGs. A typical gram-negative antibiotic-resistant bacteria called Pseudomonas sp. HLS-6 was used as a model ARB. A completed inactivation of ARB at ∼10(7) CFU/mL was achieved in 30 s, and an efficient removal rate of more than 4.0 log for specific ARGs (sul1 and intI1) was achieved within 60 min by the MM CS-based heterogeneous photo-Fenton-like process under visible light and neutral pH conditions. Mechanism investigation revealed that •O(2)(-) and (1)O(2) were the vital reactive species for ARB inactivation and ARG degradation. The formation and transformation of the active species were proposed. Furthermore, the hierarchical macro-mesoporous structure of MM CS provided excellent optical and photoelectrochemical properties that promoted the cycle of Co(3+)/Co(2+) and the effective utilization of PMS. This process was validated to be effective in various water matrices, including deionized water, underground water, source water, and secondary effluent wastewater. Collectively, this work demonstrated that the MM CS-based heterogeneous photo-Fenton-like process is a promising technology for controlling the spread of antibiotic resistance in aquatic environments.202235149504
786340.9995Mechanisms on the removal of gram-negative/positive antibiotic resistant bacteria and inhibition of horizontal gene transfer by ferrate coupled with peroxydisulfate or peroxymonosulfate. The existence of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) has been a global public environment and health issue. Due to the different cell structures, gram-positive/negative ARB exhibit various inactivation mechanisms in water disinfection. In this study, a gram-negative ARB Escherichia coli DH5α (E. coli DH5α) was used as a horizontal gene transfer (HGT) donor, while a gram-positive ARB Bacillus as a recipient. To develop an efficient and engineering applicable method in water disinfection, ARB and ARGs removal efficiency of Fe(VI) coupled peroxydisulfate (PDS) or peroxymonosulfate (PMS) was compared, wherein hydroxylamine (HA) was added as a reducing agent. The results indicated that Fe(VI)/PMS/HA showed higher disinfection efficiency than Fe(VI)/PDS/HA. When the concentration of each Fe(VI), PMS, HA was 0.48 mM, 5.15 log E. coli DH5α and 3.57 log Bacillus lost cultivability, while the proportion of recovered cells was 0.0017 % and 0.0566 %, respectively, and HGT was blocked. Intracellular tetA was reduced by 2.49 log. Fe(IV) and/or Fe(V) were proved to be the decisive reactive species. Due to the superiority of low cost as well as high efficiency and practicality, Fe(VI)/PMS/HA has significant application potential in ARB, ARGs removal and HGT inhibition, offering a new insight for wastewater treatment.202438615644
784050.9995Ferrate(VI) promotes inactivation of antibiotic-resistant bacteria and chlorine-resistant bacteria in water. The increasing problem of antibiotic resistance has garnered significant global attention. As a novel water treatment agent with strong oxidizing, disinfecting, and bactericidal properties, ferrate(VI) holds promise for inactivating antibiotic-resistant bacteria (ARB) and chlorine-resistant bacteria. The results showed that complete inactivation of ARB (10⁵ CFU/mL) was achieved when the ferrate(VI) concentration was 10 μM and the treatment duration was 5 min. For higher concentrations of ARB (10(8) CFU/mL), it was also possible to reduce the concentration by 1.73 log units. The concentration of Acinetobacter baylyi ADP1 was also reduced by 1.77 log units. Additionally, the absolute abundance of antibiotic resistance genes (ARGs), including aphA, bla(TEM), and tetA, was significantly reduced. Ferrate(VI) was rapidly consumed in the early stages of treatment, undergoing a stepwise reduction process that generated high-valent Fe intermediates and reactive oxygen species (ROS), both of which contributed to bacterial inactivation. Throughout the reaction, •O(2)(-) played a dominant role in bacterial inactivation, with H₂O₂ acting synergistically and •OH contributing at later stages, leading to ROS overload, severe cellular damage, and enhanced membrane disruption. This study confirmed that ferrate(VI) could effectively inactivate ARB and chlorine-tolerant bacteria, and reduce the abundances of ARGs.202540245720
786260.9995Synergistic effect of sulfidated nanoscale zerovalent iron in donor and recipient bacterial inactivation and gene conjugative transfer inhibition. Antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB) are widespread in urban wastewater treatment plants (UWTPs). In this research, a horizontal transfer model of recipient (Pseudomonas. HLS-6) and donor (Escherichia coli DH5α carries RP4 plasmid) was constructed to explore the effect of sulfidated nanoscale zerovalent iron (S-nZVI) on the efficiency of plasmid-mediated horizontal transfer. When the S/Fe was 0.1, the inactivation efficiency of 1120 mg/L S-nZVI on the donor and recipient bacteria were 2.36 ± 0.03 log and 3.50 ± 0.17 log after 30 min, respectively (initial ARB concentration ≈ 5 ×10(7) CFU/mL). Effects of treatment time, S/Fe molar ratio, S-nZVI dosage and initial bacterial concentration were systemically studied. S-nZVI treatment could increase the extracellular alkaline phosphatase and malondialdehyde content of the ARB, cause oxidative stress in the bacteria, destroy the cell structure and damage the intracellular DNA. This study provided evidence and insights into possible underlying mechanisms for reducing conjugative transfer, such as hindering cell membrane repair, inducing the overproduction of reactive oxygen species, inhibiting the SOS response, reducing the expression of ARGs and related transfer genes. S-nZVI could inhibit the gene conjugative transfer while inactivating the ARB. The findings provided an alternative method for controlling antibiotic resistance.202235334272
786770.9995The removal of antibiotic resistant bacteria and antibiotic resistance genes by sulfidated nanoscale zero-valent iron activating periodate: Efficacy and mechanism. Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have drawn much more attention due to their high risk on human health and ecosystem. In this study, the performance of sulfidated nanoscale zero-valent iron (S-nZVI)/periodate (PI) system toward ARB inactivation and ARGs removal was systematically investigated. The S-nZVI/PI system could realize the complete inactivation of 1 × 10(8) CFU/mL kanamycin, ampicillin, and tetracycline-resistant E. coli HB101 within 40 min, meanwhile, possessed the ability to remove the intracellular ARGs (iARGs) (including aphA, tetA, and tnpA) carried by E. coli HB101. Specifically, the removal of aphA, tetA, and tnpA by S-nZVI/PI system after 40 min reaction was 0.31, 0.47, and 0.39 log(10)copies/mL, respectively. The reactive species attributed to the E. coli HB101 inactivation were HO(•) and O(2)(•-), which could cause the destruction of E. coli HB101 morphology and enzyme system (such as superoxide dismutase and catalase), the loss of intracellular substances, and the damage of iARGs. Moreover, the influence of the dosage of PI and S-nZVI, the initial concentration of E. coli HB101, as well as the co-existing substance (such as HCO(3)(-), NO(3)(-), and humic acid (HA)) on the inactivation of E. coli HB101 and its corresponding iARGs removal was also conducted. It was found that the high dosage of PI and S-nZVI and the low concentration of E. coli HB101 could enhance the disinfection performance of S-nZVI/PI system. The presence of HCO(3)(-), NO(3)(-), and HA in S-nZVI/PI system showed inhibiting role on the inactivation of E. coli HB101 and its corresponding iARGs removal. Overall, this study demonstrates the superiority of S-nZVI/PI system toward ARB inactivation and ARGs removal.202337544470
785880.9995Photocatalytic Reactive Ultrafiltration Membrane for Removal of Antibiotic Resistant Bacteria and Antibiotic Resistance Genes from Wastewater Effluent. Biological wastewater treatment is not effective in removal of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs). In this study, we fabricated a photocatalytic reactive membrane by functionalizing polyvinylidene fluoride (PVDF) ultrafiltration (UF) membrane with titanium oxide (TiO(2)) nanoparticles for the removal of ARB and ARGs from a secondary wastewater effluent. The TiO(2)-modified PVDF membrane provided complete retention of ARB and effective photocatalytic degradation of ARGs and integrons. Specifically, the total removal efficiency of ARGs (i.e., plasmid-mediated floR, sul1, and sul2) with TiO(2)-modified PVDF membrane reached ∼98% after exposure to UV irradiation. Photocatalytic degradation of ARGs located in the genome was found to be more efficient than those located in plasmid. Excellent removal of integrons (i.e., intI1, intI2, and intI3) after UV treatment indicated that the horizontal transfer potential of ARGs was effectively controlled by the TiO(2) photocatalytic reaction. We also evaluated the antifouling properties of the TiO(2)-UF membrane to demonstrate its potential application in wastewater treatment.201829984583
782690.9995Synergistic effect of sulfidated nano zerovalent iron and persulfate on inactivating antibiotic resistant bacteria and antibiotic resistance genes. Antimicrobial resistance continues to be a rising global threat to public health. It is well recognized that wastewater treatment plants are reservoirs of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs). However, traditional disinfection techniques are not effective to simultaneously remove ARB and ARGs, and the dynamic analysis of ARB inactivation have also been deficient. In this study, sulfidated nano zerovalent iron (S-nZVI) coupled with persulfate (PS) was applied to simultaneously remove both ARB (E. coli K-12 with RP4 plasmid) and ARGs (extra- and intracellular ARGs). S-nZVI/PS completely inactivated ARB (~7.8-log reduction) within 10 min and degraded all extracellular ARGs (~8.0-log reduction) within 5 min. These efficiencies were significantly higher (decay rate constant, k = 0.138 min(-1)) than those achieved individually (S-nZVI: k = 0.076 min(-1); PS: k = 0.008 min(-1)), implying a synergistic effect between S-nZVI and PS against ARB and ARGs. The efficient removal rate of ARB was also supported by confocal microscopy and microfluidics at a single-cell level. The complete inactivation of ARB by S-nZVI/PS was also demonstrated in real drinking water and real wastewater effluent that contained natural organic matter and suspended solids. Regrowth assays showed that the treated ARB was not observed after 72 h or longer incubation, suggesting that ARB was permanently inactivated by radicals such as SO(4)(•-) and •OH. The destruction of bacterial cells compromised the removal efficiency of the intracellular ARGs, with only ~4.0-log reduction after 60 min treatment by S-nZVI/PS. Collectively, our results suggest the feasibility of S-nZVI coupled with PS for simultaneous ARB and ARGs removal in real water matrices.202133895590
7864100.9995Simultaneous removal of antibiotics and antibiotic resistant genes using a CeO(2)@CNT electrochemical membrane-NaClO system. The simultaneous removal of antibiotic and antibiotic resistance genes (ARGs) are important to inhibit the spread of antibiotic resistance. In this study, a coupled treatment system was developed using a CeO(2) modified carbon nanotube electrochemical membrane and NaClO (denoted as CeO(2)@CNT-NaClO) to treat simulated water samples containing antibiotics and antibiotic-resistant bacteria (ARB). As the mass ratio of CeO(2) to CNT was 5:7 and the current density was 2.0 mA/cm(2), the CeO(2)@CNT-NaClO system removed 99% of sulfamethoxazole, 4.6 log sul1 genes, and 4.7 log intI1 genes from the sulfonamide-resistance water samples, and removed 98% of tetracycline, 2.0 log tetA genes, and 2.6 log intI1 genes of the tetracycline-resistance water samples. The outstanding performance of the CeO(2)@CNT-NaClO system for simultaneously removing antibiotic and ARGs was mainly ascribed to the generation of multiple reactive species, including •OH, •ClO, •O(2)(-) and (1)O(2). Antibiotics can undergo efficient degradation by •OH. However, the reaction between •OH and antibiotics reduces the availability of •OH to permeate into the cells and react with DNA. Nevertheless, the presence of •OH enhancd the effects of •ClO, •O(2)(-), and (1)O on ARG degradation. Through the coupled action of •OH, •ClO, •O(2)(-), and (1)O(2), the cell membranes of ARB experience severe damage, resulting in an increase in intracellular reactive oxygen species (ROS) and a decrease in superoxide dismutase (SOD) activity. Consequently, this coordinated mechanism leads to superior removal of ARGs.202337429382
7853110.9995Natural pyrite and ascorbic acid co-enhance periodate activation for inactivation of antibiotic resistant bacteria and inhibition of resistance genes transmission: A green disinfection process dominated by singlet oxygen. The transmission of antibiotic resistance genes (ARGs) and the propagation of antibiotic resistant bacteria (ARB) threaten public health security and human health, and greener and more efficient disinfection technologies are expected to be discovered for wastewater treatment. In this study, natural pyrite and ascorbic acid (AA) were proposed as environmental-friendly activator and reductant for periodate (PI) activation to inactivate ARB. The disinfection treatment of PI/pyrite/AA system could inactivate 5.62 log ARB within 30 min, and the lower pH and higher PI and natural pyrite dosage could further boost the disinfection efficiency. The (1)O(2) and SO(4)(•-) were demonstrated to be crucial for the inactivation of ARB in PI/pyrite/AA system. The disinfection process destroyed the morphological structure of ARB, inducing oxidative stress and stimulating the antioxidant system. The PI/pyrite/AA system effectively reduced the intracellular and extracellular DNA concentration and ARGs abundance, inhibiting the propagation of ARGs. The presence of AA facilitated the activation of PI with natural pyrite and significantly increased the concentration of Fe(2+) in solution. The reusability of natural pyrite, the safety of the disinfection by-products and the inhibition of ARB regeneration indicated the application potential of PI/pyrite/AA system in wastewater disinfection.202439038380
7856120.9995Boosting Low-Dose Ferrate(VI) Activation by Layered FeOCl for the Efficient Removal of Antibiotic-Resistant Bacteria and Antibiotic Resistance Genes via Enhancing Fe(IV)/Fe(V) Generation. Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in aquatic environments pose threats to ecosystem safety and human health, which could not be efficiently removed by conventional disinfection techniques. Herein, layered FeOCl with coordinatively unsaturated Fe sites were fabricated and used to activate Fe(VI) for the efficient ARB/ARG removal in the present study. We found that highly reactive Fe(IV)/Fe(V) intermediates were generated in the FeOCl/Fe(VI) system, rapidly disinfecting 1 × 10(7) CFU mL(-1) ARB to below the limit of detection within only 6 min. Via the combination of in situ characterization and theoretical calculations, we revealed that Fe(VI) was preferentially adsorbed onto Fe sites on the (010) plane of FeOCl and subsequently activated to produce reactive Fe(IV)/Fe(V) through direct electron transfer. Meanwhile, O(2)(•-) generated from O(2) activation on the FeOCl surface enhanced Fe(VI) conversion to Fe(IV)/Fe(V). During the disinfection process, intracellular/extracellular ARGs and DNA bases were simultaneously degraded, inhibiting the potential horizontal gene transfer process. The FeOCl/Fe(VI) system could effectively disinfect ARB under complex water matrices and in real water samples including tap water, lake water, and groundwater. When integrated into a continuous-flow reactor, the FeOCl/Fe(VI) system with excellent stability successively disinfected ARB. Overall, the FeOCl/Fe(VI) system showed great promise for eliminating ARB/ARGs from water.202540739812
7821130.9994Efficient inactivation of antibiotic resistant bacteria and antibiotic resistance genes by photo-Fenton process under visible LED light and neutral pH. Antibiotic resistance has been recognized as a major threat to public health worldwide. Inactivation of antibiotic resistant bacteria (ARB) and degradation of antibiotic resistance genes (ARGs) are critical to prevent the spread of antibiotic resistance in the environment. Conventional disinfection processes are effective to inactivate water-borne pathogens, yet they are unable to completely eliminate the antibiotic resistance risk. This study explored the potential of the photo-Fenton process to inactivate ARB, and to degrade both extracellular and intracellular ARGs (e-ARGs and i-ARGs, respectively). Using Escherichia coli DH5α with two plasmid-encoded ARGs (tetA and bla(TEM)(-1)) as a model ARB, a 6.17 log ARB removal was achieved within 30 min of applying photo-Fenton under visible LED and neutral pH conditions. In addition, no ARB regrowth occurred after 48-h, demonstrating that this process is very effective to induce permanent disinfection on ARB. The photo-Fenton process was validated under various water matrices, including ultrapure water (UPW), simulated wastewater (SWW) and phosphate buffer (PBS). The higher inactivation efficiency was observed in SWW as compared to other matrices. The photo-Fenton process also caused a 6.75 to 8.56-log reduction in eARGs based on quantitative real-time PCR of both short- and long amplicons. Atomic force microscopy (AFM) further confirmed that the extracellular DNA was sheared into short DNA fragments, thus eliminating the risk of the transmission of antibiotic resistance. As compared with e-ARGs, a higher dosage of Fenton reagent was required to damage i-ARGs. In addition, the tetA gene was more easily degraded than the bla(TEM)(-1) gene. Collectively, our results demonstrate the photo-Fenton process is a promising technology for disinfecting water to prevent the spread of antibiotic resistance.202032417561
7852140.9994Pyrite from acid mine drainage promotes the removal of antibiotic resistance genes and mobile genetic elements in karst watershed with abundant calcium carbonate. More information is needed to fully comprehend how acid mine drainage (AMD) affects the phototransformation of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in karst water and sewage-irrigated farmland soil with abundant carbonate rocks (CaCO(3)) due to increasing pollution of AMD formed from pyrite (FeS(2)). The results showed FeS(2) accelerated the inactivation of ARB with an inactivation of 8.7 log. Notably, extracellular and intracellular ARGs and mobile genetic elements (MGEs) also experienced rapid degradation. Additionally, the pH of the solution buffered by CaCO(3) significantly influenced the photo-inactivation of ARB. The Fe(2+) in neutral solution was present in Fe(II) coordination with strong reducing potential and played a crucial role in generating •OH (7.0 μM), which caused severe damage to ARB, ARGs, and MGEs. The •OH induced by photo-Fenton of FeS(2) posed pressure to ARB, promoting oxidative stress response and increasing generation of reactive oxygen species (ROS), ultimately damaging cell membranes, proteins and DNA. Moreover, FeS(2) contributed to a decrease in MIC of ARB from 24 mg/L to 4 mg/L. These findings highlight the importance of AMD in influencing karst water and sewage-irrigated farmland soil ecosystems. They are also critical in advancing the utilization of FeS(2) to inactivate pathogenic bacteria.202438678706
7851150.9994Breaking antibiotic resistance: Sunlight-powered calcium peroxide for dual bactericidal and genetic elimination. Antibiotic-resistant bacteria (ARB) and associated antibiotic resistance genes (ARGs) have emerged as critical waterborne contaminants, posing serious public health risks. This study proposes a disinfection strategy through sunlight powered calcium peroxide (CaO(2)) treatment that simultaneously inactivates ARB and degrades ARGs in aquatic environments. Solar irradiation combined with CaO(2) (3.0 mM) activates dual mechanisms: alkaline-driven microbial inactivation (pH increase from 6.4 to 8.2 within 30 min) and ROS-mediated oxidative damage (ROS: (•)OH, H(2)O(2), (1)O(2) and O(2)(•-)), achieving complete 5-log inactivation of tetracycline and sulfonamides-resistant E. coli (TSRE). ARGs (tetA and sul2) showed 70-80 % reduction in absolute abundance, although the log removal did not exceed 1-log. Compared to sunlight alone, the addition of CaO(2) significantly enhanced disinfection efficiency. Alkaline and ROS-induced oxidative stress caused membrane lipid breakdown, protein denaturation, and suppression of antioxidant enzymes, along with DNA damage, lipid peroxidation, and enzyme inactivation. These effects increased membrane permeability, impaired bacterial recovery by downregulating DNA repair genes, and disrupted cellular integrity, ultimately limiting ARGs persistence. These findings highlight the synergistic effect of alkaline and oxidative stress in effectively inactivating ARB and degrading ARGs, positioning sunlight powered CaO(2) as a promising, highly efficient disinfection strategy for environmental water treatment.202540876436
7865160.9994Inactivation of antibiotic resistant bacteria by Fe(3)O(4) @MoS(2) activated persulfate and control of antibiotic resistance dissemination risk. Antibiotic resistance poses a global environmental challenge that jeopardizes human health and ecosystem stability. Antibiotic resistant bacteria (ARB) significantly promote the spreading and diffusion of antibiotic resistance. This study investigated the efficiency and mechanism of inactivating tetracycline-resistant Escherichia coli (TR E. coli) using Fe(3)O(4) @MoS(2) activated persulfate (Fe(3)O(4) @MoS(2)/PS). Under optimized conditions (200 mg/L Fe(3)O(4) @MoS(2), 4 mM PS, 35 °C), TR E. coli (∼7.5 log CFU/mL) could be fully inactivated within 20 min. The primary reactive oxygen species (ROS) responsible for TR E. coli inactivation in the Fe(3)O(4) @MoS(2)/PS system were hydroxyl radicals (•OH) and superoxide radicals (•O(2)(-)). Remarkably, the efflux pump protein was targeted and damaged by the generated ROS during the inactivation process, resulting in cell membrane rupture and efflux of cell content. Additionally, the horizontal transmission ability of residual antibiotic resistance genes (ARGs) harboring in the TR E. coli was also reduced after the inactivation treatment. This study offers an efficient approach for TR E. coli inactivation and substantial mitigation of antibiotic resistance dissemination risk.202438286046
8500170.9994Plasma induced efficient removal of antibiotic-resistant Escherichia coli and antibiotic resistance genes, and inhibition of gene transfer by conjugation. Antibiotic-resistant bacteria (ARB) and their resistance genes (ARGs) are emerging environmental pollutants that pose great threats to human health. In this study, a novel strategy using plasma was developed to simultaneously remove antibiotic-resistant Escherichia coli (AR bio-56954 E. coli) and its ARGs, aiming to inhibit gene transfer by conjugation. Approximately 6.6 log AR bio-56954 E. coli was inactivated within 10 min plasma treatment, and the antibiotic resistance to tested antibiotics (tetracycline, gentamicin, and amoxicillin) significantly decreased. Reactive oxygen and nitrogen species (RONS) including •OH, (1)O(2), O(2)•(-), NO(2)(-), and NO(3)(-) contributed to ARB and ARGs elimination; their attacks led to destruction of cell membrane, accumulation of excessive intracellular reactive oxygen substances, deterioration of conformational structures of proteins, and destroy of nucleotide bases of DNA. As a result, the ARGs (tet(C), tet(W), blaTEM-1, aac(3)-II), and integron gene intI1), and conjugative transfer frequency of ARGs significantly decreased after plasma treatment. The results demonstrated that plasma has great prospective application in removing ARB and ARGs in water, inhibiting gene transfer by conjugation.202134214852
7861180.9994The removal of antibiotic resistant bacteria and genes and inhibition of the horizontal gene transfer by contrastive research on sulfidated nanoscale zerovalent iron activating peroxymonosulfate or peroxydisulfate. Antibiotic resistant bacteria (ARB) and the antibiotic resistance genes (ARGs) dissemination via plasmid-mediated conjugation have attracted considerable attentions. In this research, sulfidated nanoscale zerovalent iron (S-nZVI)/peroxymonosulfate (PMS) and S-nZVI/peroxydisulfate (PDS) process were investigated to inactivate ARB (Escherichia coli DH5α with RP4 plasmid, Pseudomonas. HLS-6 contains sul1 and intI1 on genome DNA sequence). S-nZVI/PMS system showed higher efficiency than S-nZVI/PDS on ARB inactivation. Thus, the optimal condition 28 mg/L S-nZVI coupled with 153.7 mg/L (0.5 mM) PMS was applied to remove both intracellular ARGs (iARGs) and ARB. The oxidative damage of ARB cell was systemically studied by cell viability, intracellular Mg(2+) levels, the changes of extracellular and internal structure, integrity of cell walls and membranes and enzymatic activities. S-nZVI/PMS effectively inactivated ARB (~7.32 log) within 15 min. These effects were greatly higher than those achieved individually. Moreover, removal efficiencies of iARGs sul1, intI1 and tetA were 1.52, 1.79 and 1.56 log, respectively. These results revealed that S-nZVI and PMS have a synergistic effect against ARB and iARGs. The regrowth assays illustrated that the ARB were effectively inactivated. By verifying the inhibitory impacts of S-nZVI/PMS treatment on conjugation transfer, this work highlights a promising alternative technique for inhibiting the horizontal gene transfer.202234482079
7866190.9994Inactivation of sulfonamide antibiotic resistant bacteria and control of intracellular antibiotic resistance transmission risk by sulfide-modified nanoscale zero-valent iron. The inactivation of a gram-negative sulfonamide antibiotic resistant bacteria (ARB) HLS.6 and removal of intracellular antibiotic resistance gene (ARG, sul1) and class I integrase gene (intI1) by nanoscale zero-valent iron (nZVI) and sulfide-modified nZVI (S-nZVI) with different S/Fe molar ratios were investigated in this study. The S-nZVI with high sulfur content (S/Fe = 0.05, 0.1, 0.2) was superior to nZVI and the treatment effect was best when S/Fe was 0.1. The ARB (2 × 10(7) CFU/mL) could be completely inactivated by 1.12 g/L of S-nZVI (S/Fe = 0.1) within 15 min, and the removal rates of intracellular sul1 and intI1 reached up to 4.39 log and 4.67 log at 60 min, respectively. Quenching experiments and flow cytometry proved that reactive oxygen species and adsorption were involved in the ARB inactivation and target genes removal. Bacterial death and live staining experiments and transmission electron microscopy showed that the ARB cell structure and intracellular DNA were severely damaged after S-nZVI treatment. This study provided a potential alternative method for controlling the antibiotic resistance in aquatic environment.202032585519