Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu 610000, China; Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610000, China.
Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu 610000, China; Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610000, China; Molecular Medicine Research Centre of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650000, China.
Sci Total Environ. 2024 Nov 15;951:175639. doi: 10.1016/j.scitotenv.2024.175639. Epub 2024 Aug 20.
Antibiotic resistance (AMR) poses a significant global health challenge, with swine farms recognized as major reservoirs of antibiotic resistance genes (ARGs). Recently, bacterial membrane vesicles (BMVs) have emerged as novel carriers mediating horizontal gene transfer. However, little is known about the ARGs carried by BMVs in swine farm environments and their transfer potential. This study investigated the distribution, sources, and microbiological origins of BMVs in three key microbial habitats of swine farms (feces, soil, and fecal wastewater), along with the ARGs and mobile genetic elements (MGEs) they harbor. Characterization of BMVs revealed particle sizes ranging from 20 to 500 nm and concentrations from 10 to 10 particles/g, containing DNA and proteins. Metagenomic sequencing identified BMVs predominantly composed of members of the Proteobacteria phyla, including Pseudomonadaceae, Moraxellaceae, and Enterobacteriaceae, carrying diverse functional genes encompassing resistance to 14 common antibiotics and 74,340 virulence genes. Notably, multidrug resistance, tetracycline, and chloramphenicol resistance genes were particularly abundant. Furthermore, BMVs harbored various MGEs, primarily plasmids, and demonstrated the ability to protect their DNA cargo from degradation and facilitate horizontal gene transfer, including the transmission of resistance genes. In conclusion, this study reveals widespread presence of BMVs carrying ARGs and potential virulence genes in swine farm feces, soil, and fecal wastewater. These findings not only provide new insights into the role of extracellular DNA in the environment but also highlight concerns regarding the gene transfer potential mediated by BMVs and associated health risks.
抗生素耐药性（AMR）是一个全球性的重大健康挑战，养猪场被认为是抗生素耐药基因（ARGs）的主要储存库。最近，细菌膜泡（BMVs）作为介导水平基因转移的新型载体而备受关注。然而，关于养猪场环境中 BMVs 携带的 ARGs 及其转移潜力，我们知之甚少。本研究调查了三种养猪场关键微生物生境（粪便、土壤和粪便污水）中 BMVs 的分布、来源和微生物起源，以及它们携带的 ARGs 和移动遗传元件（MGEs）。对 BMVs 的特征分析表明，其粒径范围为 20 至 500nm，浓度为 10 至 10 个/克，包含 DNA 和蛋白质。宏基因组测序鉴定出 BMVs 主要由变形菌门的成员组成，包括假单胞菌科、莫拉氏菌科和肠杆菌科，携带多种功能基因，涵盖对 14 种常见抗生素和 74340 种毒力基因的抗性。值得注意的是，多药耐药、四环素和氯霉素耐药基因尤为丰富。此外，BMVs 还携带各种 MGEs，主要是质粒，并表现出保护其 DNA 货物免受降解和促进水平基因转移的能力，包括耐药基因的传递。综上所述，本研究揭示了养猪场粪便、土壤和粪便污水中广泛存在携带 ARGs 和潜在毒力基因的 BMVs。这些发现不仅为环境中细胞外 DNA 的作用提供了新的见解，还强调了 BMVs 介导的基因转移潜力及其相关健康风险。
