摘要
      畜禽粪便中的抗生素耐药性污染是一个持续存在的问题，已引起公众的关注。堆肥是一种生态友好的生物过程，可以使牲畜粪便无害且资源丰富。然而，在潜在毒性砷水平造成的压力下，蚯蚓堆肥对牲畜粪便中抗生素耐药性的影响知之甚少。在此，进行了实验室规模的蚯蚓堆肥，以全面评估新鲜蚯蚓粪便中抗生素抗性基因（ARGs）和相关微生物的变化，以及当它们被砷污染的牛粪喂养时，蚯蚓堆肥产品的健康状况（即营养素可得性和酶活性）。结果表明，蚯蚓与牛粪的相互作用导致ARG浓度显著降低，尤其是四环素ARGs（tet-ARGs）、β-内酰胺ARGs和喹诺酮类ARGs。然而，砷以剂量依赖的方式显著增强了蚯蚓模型中ARG的积累。此外，蚯蚓堆肥增加了转化产物中拟杆菌的百分比。此外，低浓度的砷暴露促进了变形杆菌的增殖，而高浓度的砷对变形杆菌的影响很小。我们的研究为砷改性牛粪蚯蚓堆肥过程中抗生素耐药性和相关微生物的变化提供了宝贵的见解，对于解释蚯蚓对环境的影响和提高我们对土壤无脊椎动物互惠互利的理解至关重要。
Abstract
Antibiotic resistance pollution in livestock manure is a persistent issue that has drawn public attention. Vermicomposting is an ecofriendly biological process that can render livestock manure harmless and resourceful. However, little is known about the impact of vermicomposting on antibiotic resistance in livestock manure under stress caused by potentially toxic arsenic levels. Herein, lab-scale vermicomposting was performed to comprehensively evaluate the shift in antibiotic resistance genes (ARGs) and related microorganisms in fresh earthworm casts as well as vermicompost product health (i.e., nutrient availability and enzyme activity) when they were fed on arsenic-contaminated cow manure. The results showed that the earthworms’ interaction with cow dung led to a significant reduction in ARG concentrations, especially for tetracycline ARGs (tet-ARGs), β-lactam ARGs (bla-ARGs), and quinolone ARGs (qnr-ARGs). However, arsenic significantly enhanced ARG accumulation in earthworm casts in a dose-dependent manner. Moreover, vermicomposting increased the percentage of Bacteroidota in the converted products. Furthermore, arsenic exposure at low concentrations promoted the proliferation of Proteobacteria, whereas high concentrations had little effect on Proteobacteria. Our study provides valuable insight into the changes in the antibiotic resistome and related microorganisms during vermicomposting of arsenic-amended cow manure, and it is crucial to explain the environmental impact of earthworms and improve our understanding of the reciprocal benefits of soil invertebrates.

https://www.mdpi.com/1660-4601/19/21/14475