Manure application amplified the co-selection of quaternary ammonium disinfectant and antibiotic on soil antibiotic resistome

Insights into the drivers of antibiotic resistance gene migration in soil-lettuce system with manure application from different sources

The application of livestock manure serves as a significant source of ARGs in soils. To study the impact of manure application on the migration of ARGs in the soil-plant system, we set different application ratios (1 %, 3 %, 8 %) of chicken and cow manure for treatment. The study's results demonstrated that the application of organic fertilizers increased the quantity of resistance genes in soil, root, and leaf zones. This change was influenced by the type and proportion of the organic fertilizers used. ARGs and MGEs exhibited the highest absolute enrichment levels in leaf tissues (2.53 and 2.01 times, respectively) with the 3 % cow manure treatment. In contrast, chicken manure exhibited the highest enrichment levels after the 1 % addition (2.51 and 1.81 times, respectively). The applied manure exhibited a high degree of similarity in bacterial community composition with the soil-lettuce system, indicating that ARGs may spread through microorganisms in this system. This study demonstrated that the evolution of bacterial community structure plays a pivotal role in mediating and driving the migration of ARGs within manure-amended soil-plant ecosystems, providing a theoretical basis for understanding the transmission of ARGs in soils and plants due to agricultural production activities.

Significant effects of earthworm species on antibiotic resistome in livestock manure as revealed by metagenomic analysis

Animal-derived antibiotic resistance genes (ARGs) have emerged as a critical threat, while vermicomposting has been recognized as an effective strategy for reducing ARGs. However, the efficacy of different earthworm species in reducing ARGs remains poorly understood. In this study, 72 vermicompost and earthworm gut samples were collected from various earthworm farms to evaluate the impact of vermicomposting with different earthworm species on ARGs via metagenomic analysis. Approximately 28 ARG types were detected in gut and vermicompost samples. There were significant differences in ARGs among the four species of earthworm composting systems (p < 0.05), and each species possessed its dominant ARGs and microbes. Proteobacteria represented the predominant bacterial phylum within the gut microbiota of Pheretima guillelmi (46.89 %) and Eisenia fetida (48.42 %), whereas Euryarchaeota (36.71 %) and Actinobacteria (39.42 %) were the most abundant in Perionyx excavatus and Eudrilus eugeniae, respectively. The overall abundance of ARGs in vermicompost processed by Eisenia fetida (0.18 copies16S rRNA gene copies) was lower than that observed in other earthworm species (0.23-0.39 copies/16S rRNA gene copies), with gut microbial identified as a key determinant of variations in ARG reduction. These findings provide valuable insights into selecting suitable earthworm species to promote ARG degradation, thus contributing to the decrease in ARG dissemination risks in agricultural ecosystems.

Construction of 0-dimensional silver quantum dot/MoSe2@MXene/3-dimensional porous copper foam composite electrodes with heterogeneous interfaces for synergistic electrocatalytic degradation of antibiotics

This study proposes a novel and efficient Ag quantum dots (QDs)/MoSe2@two-dimensional transition metal carbide/nitride (MXene)/copper foam (CF) composite electrode to address the challenge of electrocatalytic degradation of antibiotics in water. The electrode formed a unique electron donor-acceptor system by loading Ag QDs and heterostructured nanosheets on CF, significantly facilitating charge transfer and segregation at the interface. The catalytically active sites at the edges and defective locations of MoSe2 in conjunction with the two-dimensional MXene structure, which formed an efficient electron transfer channel, promoted the electron transfer from the interior to the surface and accelerated the hydrogen adsorption and reduction reactions. Moreover, the charge redistribution at the interface of Ag QDs and MoSe2@MXene formed interfacial dipoles, increasing the active sites on the catalyst surface and promoting the generation of cathodic atomic hydrogen (H*). Under optimal conditions, the degradation rate of tigecycline (TGC) reached as high as 90.1 % ± 2.4 % within 60 min. The anode-generated OH and HClO, along with the cathode-generated H, further promoted the degradation of TGC through co-catalysis. The degradation pathways were analyzed using density-functional theory (DFT) calculations and liquid chromatography-mass spectrometry (LC-MS) techniques. Moreover, toxicity analysis of the degradation products was carried out to ensure the safety of the treated wastewater discharge. A reflux continuous effluent reactor was also designed to achieve high degradation efficiency and low energy consumption after stable operation, laying the foundation for industrial applications. This technology provides new ideas for the design of green, efficient, stable, and low-consumption electrocatalytic reactors and contributes to a sustainable future environment.

Knowledge, attitudes, and practice of medical students towards the use of benzalkonium chloride in hand sanitization from the perspective of environmental sustainability

Control measures for disinfectant pollution and related anthropogenic behaviors are required. Benzalkonium chloride (BAC) with widespread use especially in hand sanitization is highlighted as a representative disinfectant emerging contaminant. This cross-sectional survey was conducted to assess the knowledge, attitudes, practice regarding BAC use for hand hygiene among medical students from the perspective of environmental sustainability. Of the 703 responding students, only 3.7% had never used hand sanitizer products containing BAC. But few students paid attention to the "environmental friendliness" property of products when consumption. Mean knowledge test score was 1.90 out of 5, suggesting poor knowledge regarding BAC use. Most students had positive attitudes toward source control of BAC pollution and strong intentions to learn more about environmental knowledge related to BAC and other disinfectants. Data indicated that medical students had positive attitudes but lacked knowledge and practices towards eco-friendly disinfectant use, thus further training and practice standards are required.