Search Results (408)

Antimicrobial resistance (AMR) has emerged as a planetary health emergency, driven not only by the clinical misuse of antibiotics but also by diverse environmental dissemination pathways. This review critically examines the role of environmental compartments—water, soil, and air—as dynamic reservoirs and transmission routes for antibiotic-resistant bacteria (ARB) and resistance genes (ARGs). Recent metagenomic, epidemiological, and mechanistic evidence demonstrates that anthropogenic pressures—including pharmaceutical effluents, agricultural runoff, untreated sewage, and airborne emissions—amplify resistance evolution and interspecies gene transfer via horizontal gene transfer mechanisms, biofilms, and mobile genetic elements. Importantly, it is not only highly polluted rivers such as the Ganges that contribute to the spread of AMR; even low concentrations of antibiotics and their metabolites, formed during or after treatment, can significantly promote the selection and dissemination of resistance. Environmental hotspots such as European agricultural soils and airborne particulate zones near wastewater treatment plants further illustrate the complexity and global scope of pollution-driven AMR. The synergistic roles of co-selective agents, including heavy metals, disinfectants, and microplastics, are highlighted for their impact in exacerbating resistance gene propagation across ecological and geographical boundaries. The efficacy and limitations of current mitigation strategies, including advanced wastewater treatments, thermophilic composting, biosensor-based surveillance, and emerging regulatory frameworks, are evaluated. By integrating a One Health perspective, this review underscores the imperative of including environmental considerations in global AMR containment policies and proposes a multidisciplinary roadmap to mitigate resistance spread across interconnected human, animal, and environmental domains. Full article

As the primary biological risk threatening safe dairy production, bovine mastitis control highly relies on environmental disinfection measures. However, the mechanisms by which chemical disinfectants influence host–environment microbial interactions remain unclear. This study systematically investigated the disinfection efficacy and regulatory effects on microbial community composition and diversity of glutaraldehyde-benzalkonium chloride (BAC) and glutaraldehyde-didecyl dimethyl ammonium bromide (DAB) at recommended concentrations (2–5%), using 80 environmental samples from intensive dairy farms in Xinjiang, China. Combining 16S rDNA sequencing with culturomics, the results showed that BAC achieved a disinfection rate of 99.33%, higher than DAB’s 97.87%, and reduced the environment–gut microbiota similarity index by 23.7% via a cationic bacteriostatic film effect. Microbiome analysis revealed that BAC selectively suppressed Fusobacteriota abundance (15.67% reduction) and promoted Bifidobacterium proliferation (7.42% increase), enhancing intestinal mucosal barrier function through butyrate metabolism. In contrast, DAB induced Actinobacteria enrichment in the environment (44.71%), inhibiting pathogen colonization via bioantagonism. BAC’s long-acting bacteriostatic properties significantly reduced disinfection costs and mastitis incidence. This study first elucidated the mechanism by which quaternary ammonium compound (QAC) disinfectants regulate host health through “environment-gut” microbial interactions, providing a critical theoretical basis for developing precision disinfection protocols integrating “cost reduction-efficiency enhancement-risk mitigation.” Full article

Pseudomonas aeruginosa is a highly adaptable opportunistic pathogen with significant clinical relevance in both human and veterinary medicine. Despite its well-documented role in hospital-acquired infections in human healthcare settings, its persistence and transmission within veterinary clinics remain underexplored. This review highlights the overlooked status of veterinary facilities as environmental reservoirs and amplification points for multidrug-resistant (MDR) P. aeruginosa, emphasizing their relevance to One Health surveillance. We examine the bacterium’s environmental survival strategies, including biofilm formation, resistance to disinfectants, and tolerance to nutrient-poor conditions that facilitate the long-term colonization of moist surfaces, drains, medical equipment, and plumbing systems. Common transmission vectors are identified, including asymptomatic animal carriers, contaminated instruments, and the hands of veterinary staff. The review synthesizes current data on antimicrobial resistance in environmental isolates, revealing frequent expression of efflux pumps and mobile resistance genes, and documents the potential for zoonotic transmission to staff and pet owners. Key gaps in environmental monitoring, infection control protocols, and genomic surveillance are identified, with a call for standardized approaches tailored to the veterinary context. Control strategies, including mechanical biofilm disruption, disinfectant cycling, effluent monitoring, and staff hygiene training, are evaluated for feasibility and impact. The article concludes with a One Health framework outlining cross-species and environmental transmission pathways. It advocates for harmonized surveillance, infrastructure improvements, and intersectoral collaboration to reduce the risk posed by MDR P. aeruginosa within veterinary clinical environments and beyond. By addressing these blind spots, veterinary facilities can become proactive partners in antimicrobial stewardship and global resistance mitigation. Full article

The aim of this study was to elucidate all the degradation byproducts (DBPs) of bemotrizinol (BEMT) that are associated with sodium hypochlorite treatment. BEMT is a UV filter that is found not only in many personal care products, such as sunscreen and cosmetics, but also as an additive in plastics or clothing to protect them from damage that results from absorbed radiation. BEMT has been detected in wastewater, surface water, and some lake sediments, in quantities from a few ng/L to hundreds of ng/L, to such an extent that, today, it is considered an emerging pollutant. In this study, the UV filter was subjected to oxidation with sodium hypochlorite, which is an oxidant at the base of the disinfection process that is used in most wastewater treatment plants or in swimming pools. Using different chromatographic methods (CC, TLC, HPLC, and GC), the resulting DBP mixture was separated into its main components, which were then identified using one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry. Nineteen DBPs were isolated, and a plausible reaction mechanism was proposed to explain how they were obtained. Full article

Multifunctional water-treatment materials urgently need to be developed to avoid normal organic matter, inorganic anions, resistant bacteria, and hazardous disinfection by-products in conventional drinking water treatment strategies. While quaternary ammonium pyridine resins (QAPRs) possess porous adsorption structures and incorporate antibacterial groups, enabling simultaneous water disinfection and purification, their limited bactericidal efficacy hinders broader utilization. Therefore, a deeper understanding of the structure-dependent antimicrobial mechanism in QAPRs is crucial for improving their antibacterial performance. Hexyl (C₆) was proved to be the optimal antibacterial alkyl in the QAPRs. A new antibacterial quaternary ammonium pyridine resin Py-61 was prepared by more surficial bactericidal N⁺ groups and higher efficient antibacterial hexyl, performing with the excellent antibacterial efficiency of 99.995%, far higher than the traditional resin Py-6C (89.53%). The antibacterial resin Py-61 completed the disinfection of sand-filtered water independently to produce safe drinking water, removing the viable bacteria from 3600 to 17 CFU/mL, which meets the drinking water standard of China in GB5749-2022 (<100 CFU/mL). Meanwhile, the contaminants in sand-filtered water were obviously removed by the resin Py-61, including anions and dissolved organic matter (DOM). The resin Py-61 can be regenerated by 15% NaCl solution, and keeps the reused antibacterial efficiency of >99.97%. As an integrated disinfection–purification solution, the novel antibacterial resin presents a promising alternative for enhancing safety in drinking water treatment. Full article

Stormwater pollution from residual chlorine after outdoor disinfection with sodium hypochlorite is an increasing environmental challenge due to its potential negative impact on aquatic ecosystems. Even at low concentrations, residual chlorine can disrupt the stability of water ecosystems. In this regard, stormwater treatment requires innovative and green solutions such as green infrastructure (rain gardens) using the plant phytoremediation technique to reduce the amount of residual chlorine. This study explores the interactions between residual chlorine retained by plants in a rain garden and different microelements. Selected plants were analyzed via spectroscopy, and possible interactions with elements such as chlorine (Cl), phosphorus (P), zinc (Zn), iron (Fe), calcium (Ca), potassium (K), nickel (Ni), silicon (Si), manganese (Mn), magnesium (Mg), chromium (Cr), and cadmium (Cd) were determined using Python-based analysis. Chlorine presented significant positive correlations with cadmium (0.39–0.53) and potassium (0.51–0.55), while negative correlations were found between silicon and chlorine (−0.48–−0.54) and chlorine and iron (−0.45–−0.51). The correlations between chlorine and microelements suggest both common uptake mechanisms and mutual interactions. These results provide a better understanding of the behavior of chlorine in rain gardens and its interactions with other materials, which is especially valuable for designing green infrastructure. This research can help to develop sustainable solutions that reduce environmental pollution and strengthen urban adaptation to climate change. Full article

Endodontic infections are characterized by complex polymicrobial communities residing within the intricate root canal system. Traditional chemomechanical methods frequently fail to achieve complete microbial eradication, especially in cases involving biofilm-forming and resistant species. This systematic review synthesizes current evidence on the molecular basis and antimicrobial efficacy of the neodymium-doped yttrium aluminum garnet (Nd:YAG) laser in root canal disinfection, particularly against polymicrobial infections. A comprehensive literature search was conducted in the PubMed, Embase, Scopus, and Cochrane databases in accordance with PRISMA 2020 guidelines. Experimental and preclinical studies evaluating the bactericidal properties of Nd:YAG laser therapy were included. The Nd:YAG laser demonstrated significant reductions in total microbial load through photothermal effects, including denaturation of proteins, disruption of cell membranes, and degradation of mixed-species biofilms. Although complete sterilization was not consistently achieved, its ability to penetrate dentinal tubules and target microbial consortia offers substantial adjunctive value. Standardization of laser parameters and further clinical studies are needed to validate these findings and establish Nd:YAG laser use in routine endodontic disinfection protocols. Full article

In South Korea, issues have been raised regarding exposure to humidifier disinfectant products containing certain chemicals postulated to induce lung diseases in consumers. Several rodent studies utilizing whole-body inhalation, which comprises freely moving animals breathing through the nares, and intranasal instillation involving restraint, were conducted by various Korean Governmental Agencies on these products to investigate whether there is a causal relationship between these products and the development of lung diseases. In particular, the humidifier disinfectant product Kathon, containing chloromethylisothiazolinone and methylisothiazolinone (CMIT and MIT), when directly introduced into inhalation chambers at varying concentrations for up to 13 weeks, produced no significant histopathological alterations and no marked changes in pulmonary function parameters. Further, there was no evidence of cytotoxicity; total and differential cell counts did not differ from control. In addition, the levels of cytokine markers of inflammation were not markedly altered. In contrast to published papers utilizing intratracheal and intranasal instillation, where the animal is anesthetized and chemical bypasses the defense mechanisms in the respiratory tract, then reaches the pulmonary region, ignoring recommended dose levels was found to initiate fibrotic responses in mice and rats. However, the usefulness of experimental results to extrapolate to humans obtained following intratracheal and intranasal instillation studies is of limited value because the data generated did not use a realistic design and appropriate dosimetry. Therefore, these findings have significant drawbacks in their use to characterize an inhalation risk for pulmonary fibrosis in humans and cannot be used for the extrapolation of such risk to humans. It is thus evident that the inhalation data generated by the Korean Regulatory Agencies are more realistic and show that exposure to CMIT and MIT does not initiate pulmonary fibrosis. Although inhalation studies still do not fully replicate real-world human exposure scenarios and have limitations for direct extrapolation to humans, they are nevertheless more appropriate than intratracheal or intranasal instillation models. Full article

Background: The Er:YAG laser has gained attention in dentistry for its potential to enhance microbial disinfection through targeted photothermal and photoacoustic mechanisms. Objective: This systematic review aimed to evaluate the antibacterial and bactericidal efficacy of Er:YAG laser therapy across clinically relevant oral pathogens in in vitro models. Methods: Following the PRISMA 2020 guidelines, a systematic search of PubMed, Embase, Scopus, and the Cochrane Library was conducted for studies published between 2015 and 2025. The review protocol was registered with PROSPERO (CRD420251031368). Eligibility criteria included in vitro or animal studies assessing the bactericidal effects of the Er:YAG laser on oral bacteria or fungi, either alone or in combination with chemical disinfectants. Study selection, data extraction, and quality assessment were conducted independently by multiple reviewers. Results: Ten in vitro studies met inclusion criteria. The Er:YAG laser demonstrated significant antibacterial effects against Enterococcus faecalis, Streptococcus mutans, Porphyromonas gingivalis, Candida albicans, and other species. Greater bacterial reduction was consistently observed when the laser was combined with adjunctive irrigants such as sodium hypochlorite or hydrogen peroxide. The laser was effective in reducing biofilm biomass and viable counts, particularly in complex anatomical settings. Most studies were rated as low risk of bias. Conclusions: Er:YAG laser therapy is a promising adjunctive tool for microbial disinfection in dentistry, particularly in challenging anatomical sites. Further well-designed in vivo and clinical studies are needed to confirm its efficacy and determine optimal treatment parameters. Full article

This review presents a comprehensive overview of recent advances in TiO₂-based photoelectrocatalysis (PEC), with an emphasis on material design strategies to enhance visible-light responsiveness and charge carrier dynamics. Key approaches—including elemental doping, defect engineering, heterojunction construction, and plasmonic enhancement—are systematically discussed in relation to their roles in modulating energy band structures and promoting charge separation. Beyond fundamental mechanisms, the review highlights the broad environmental and energy-related applications of TiO₂-driven PEC systems, encompassing the degradation of persistent organic pollutants, microbial disinfection, heavy metal removal, photoelectrochemical water splitting for hydrogen production, and CO₂ reduction. Recent progress in integrating PEC systems with energy harvesting modules to construct self-powered platforms is critically examined. Current limitations and future directions are also outlined to guide the rational development of next-generation TiO₂-based photoelectrocatalytic systems for sustainable environmental remediation and solar fuel conversion. Full article

Antimicrobial resistance (AMR) has emerged as a critical global public health threat, exacerbating healthcare burdens and imposing substantial economic costs. Currently, AMR contributes to nearly five million deaths annually worldwide, surpassing mortality rates of any single infectious disease. The economic burden associated with AMR-related disease management is estimated at approximately $730 billion per year. This review synthesizes current research on the mechanisms and multifaceted drivers of AMR development and dissemination through the lens of the One Health framework, which integrates human, animal, and environmental health perspectives. Intrinsic factors, including antimicrobial resistance genes (ARGs) and mobile genetic elements (MGEs), enable bacteria to evolve adaptive resistance mechanisms such as enzymatic inactivation, efflux pumps, and biofilm formation. Extrinsic drivers span environmental stressors (e.g., antimicrobials, heavy metals, disinfectants), socioeconomic practices, healthcare policies, and climate change, collectively accelerating AMR proliferation. Horizontal gene transfer and ecological pressures further facilitate the spread of antimicrobial-resistant bacteria across ecosystems. The cascading impacts of AMR threaten human health and agricultural productivity, elevate foodborne infection risks, and impose substantial economic burdens, particularly in low- and middle-income countries. To address this complex issue, the review advocates for interdisciplinary collaboration, robust policy implementation (e.g., antimicrobial stewardship), and innovative technologies (e.g., genomic surveillance, predictive modeling) under the One Health paradigm. Such integrated strategies are essential to mitigate AMR transmission, safeguard global health, and ensure sustainable development. Full article

Polyphenols show promising application prospects as a novel natural disinfectant for drinking water. This study employed a simulated pipe network system to investigate the effects of tea polyphenols at an initial concentration of 5 mg/L on the characteristics of biofilm on pipe walls and microbial community succession patterns under different water ages (12–48 h). The results showed that with increasing water age, the tea polyphenol residual concentration gradually decreased, and the biofilm structure significantly evolved: the surface roughness increased from 5.57 nm to 32.8 nm, and the biofilm thickness increased from 40 nm to 150 nm. Microbial community diversity exhibited a trend of first increasing and then decreasing, with the Shannon index reaching its peak (2.847) at a water age of 36 h and remaining significantly higher than the control group (1.336) at all stages. High-throughput sequencing revealed a transition from a single dominant genus of Methylophilus (54.41%) at a water age of 12 h to a multi-genus coexistence pattern at a water age of 48 h, with Methylophilus (24.33%), unclassified_Saprospiraceae (21.70%), and Hydrogenophaga (16.52%) as the main dominant groups. Functional bacterial groups exhibited temporal changes, with biofilm colonization-related genera (Caulobacter, Sphingobium) reaching their peaks at 36 h, while special metabolic genera (Methylophilus, Hydrogenophaga) dominated at 48 h. Potential pathogens in the tea polyphenol treatment groups were effectively controlled at low levels (<0.21%), except for a temporary increase in Legionella (6.50%) at 36 h. Tea polyphenols’ selective inhibition mechanism helps suppress the excessive proliferation of specific genera and reduces the risk of potential pathogen outbreaks. This has important implications for ensuring the microbiological safety of drinking water. Full article

Sodium hypochlorite is a commonly used disinfectant in reclaimed water, and the decay law of its free chlorine directly affects the disinfection effect and the safety of reclaimed water. Currently, most of the decay studies have been carried out on the temperature, pH value, and concentration of organic matter in water, without fully considering the differences between fresh and corroded pipeline materials and their effects. This study aims to compare the influences of fresh and corroded carbon steels on the decay law of sodium hypochlorite through dynamic reaction devices and static flask experiments, based on simulations using uncorroded and pre-corroded carbon steel hanging plates. The effects of Fe⁰ and corrosion products on sodium hypochlorite decay are investigated to provide data support for disinfection strategies in reclaimed water distribution networks. By integrating DPD spectrophotometry, ATP detection, XRD analysis, and corrosion weight loss analysis, the microbial control efficacy and corrosion of sodium hypochlorite under the effects of fresh and corroded carbon steels are compared. The differences in decay kinetics are quantified using the restricted first-order decay model, and the dominant mechanisms of sodium hypochlorite consumption that cause differences in the effectiveness of the action are explored. The influences of fresh and corroded carbon steels on the decay are evaluated. Additionally, the percentages of consumption are also analyzed. The results show that in order to effectively kill microorganisms while reducing corrosion, it is recommended to add sodium hypochlorite under simulated conditions for fresh and corroded carbon steels to achieve free chlorine concentrations of 5 mg/L and 9 mg/L in the water, respectively. The effective control time of sodium chlorate on microorganisms in the bulk of the water under the fresh carbon steel conditions can be maintained for up to 48 h. However, under the corroded carbon steel conditions, the activity of microorganisms in the bulk of the water is relatively high, with an effective action time of only 8 h. The decay coefficient of sodium chlorate under the corroded carbon steel conditions is 2.61~6.94 times that of the fresh carbon steel. The additional average consumption of sodium hypochlorite under the corroded carbon steel conditions is 13.91~26.57% compared to the fresh carbon steel. Both Fe⁰ and corrosion products accelerate the decay of sodium hypochlorite in the initial stage, with an average consumption increase rate of 18.9% for Fe⁰ and 17.4% for corrosion products. The bulk decay coefficient is 0.073 h⁻¹, and the wall decay coefficient represented by Fe⁰ is 0.204 h⁻¹, which is higher than the wall decay coefficient represented by corrosion products, which is 0.077 h⁻¹. Full article

N-nitroso dimethylamine (NDMA), a common nitrogen disinfection by-product and carcinogen, can be removed using rapid sand filtration (RSF) after coagulation; however, its removal mechanism has not been extensively studied. This study analyzed NDMA and the water pollutant parameter removal rate change tendency in the filtrates of simulated supernatants directly and after enhanced coagulation (EC) using composite PAC/PDMDAAC that mimics treated Yangtze River water separated into blank, single-component, and mixed multi-component (MMC) water systems containing NDMA and pollutants like diatomite (DTA), humic acid salt (HAs), dimethyl amine (DMA), and ammonium nitrate (NH₄NO₃). Meanwhile, a correlation analysis of removal rate changes and adsorption analysis using SEM (surface morphology), polar functional groups, and zeta potentials (surface charge) were performed to obtain mechanistic insights into NDMA removal via adsorption. The results revealed that removal rates gradually increased with an increasing volume of filtrates, and there were correlations for NDMA-HAs, NDMA-DMA, NDMA-DTA, and NDMA-NH₄NO₃. The highest NDMA removal rates in the blank system were 10.29% using RSF directly and 12.84% after enhanced coagulation, indicating improved efficiency with coagulation. However, single and mixed systems showed that NDMA removal rate changes were enhanced by water pollutants and coagulation functions. The NDMA removal mechanism was verified, and it was revealed that the level of NDMA adsorption on water pollutants varies based on microstructure, available polar functional groups, and surface charge interactions that are strengthened by coagulation functions for improving the affinity of NDMA and pollutants on the sand surface. These findings provide new insights into NDMA removal mechanisms via adsorption and highlight the role of water pollutants and enhanced coagulation in strengthening rapid sand filtration for NDMA removal. Full article

While conventional sericulture has developed effective disinfection methods, the increasing demand for silk and pupae is driving mechanization, potentially altering or introducing silkworm pathogens. New disinfection strategies are essential for sustainable sericulture production. This study first investigated the bacterial community differences between conventional and mechanized silkworm-rearing environments. Then, under the mechanized environment, we evaluated three commercially available disinfectants with different mechanisms: hypochlorous acid (HClO), nano platinum-polyhexamethylene guanide (Pt-PHMG), and medium-chain fatty acids (MCFA). Our results indicated significant bacterial differences between the two environments, with potential pathogenic bacteria present in both environments. Moreover, the bacterial communities remained relatively stable, while conventional disinfection methods were less effective in mechanized conditions. In contrast, regardless of whether they were applied before or after silkworm rearing, all three disinfectants demonstrated significant efficacy, with the total environmental bacterial load reduced by approximately 0.5 to 1 order of magnitude after application. Among them, Pt-PHMG exhibited the best performance by inhibiting pathogens such as Staphylococcus, Enterococcus, and Bacillus, followed by MCFA and HClO. The results also suggested a need for stronger disinfection strategies after silkworm rearing. These findings not only provide important hygiene practices to ensure mechanized silkworm rearing, but also offer valuable insights for the future development of disinfection strategies in modern sericulture. Full article