Zhang Yuan, Ji Yan, Tang Xinyue, Chen Minglong, Su Jianqiang
School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China.
Key Laboratory of Urban Pollutant Conversion, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.
Environ Sci Pollut Res Int. 2024 May;31(23):34295-34308. doi: 10.1007/s11356-024-33509-1. Epub 2024 May 3.
Fertilization can change the composition of antibiotic resistance genes(ARGs) and their host bacteria in agricultural fields, while complex microbial activities help ARGs into crops and transmit them to humans through agricultural products.Therefore, this study constructed a farmland food chain with soil-lettuce-snail as a typical structure, added genetically engineered Pseudomonas fluorescens containing multidrug-resistant plasmid RP4 to track its spread in the farmland food chain, and used different fertilization methods to explore its influence on the spread and diffusion of ARGs and intl1 in the farmland food chain. It was found that exogenous Pseudomonas can enter plants from soil and pass into snails' intestines, and there is horizontal gene transfer phenomenon of RP4 plasmid in bacteria. At different interfaces of the constructed food chain, the addition of exogenous drug-resistant bacteria had different effects on the total abundance of ARGs and intl1. Fertilization, especially manure, not only promoted the spread of Pseudomonas aeruginosa and the transfer of RP4 plasmid levels, but also significantly increased the total abundance of ARGs and intl1 at all interfaces of the constructed food chain. The main ARGs host bacteria in the constructed food chain include Proteobacteria, Bacteroides, and Firmicutes, while Flavobacterium of Bacteroides is the unique potential host bacteria of RP4 plasmid. In conclusion, this study provides a reference for the risk assessment of ARGs transmitted to the human body through the food chain, and has important practical significance to reduce the antibiotic resistance contamination of agricultural products and ensure the safety of vegetable basket.
受精作用会改变农田中抗生素抗性基因（ARGs）及其宿主细菌的组成，而复杂的微生物活动会促使ARGs进入作物，并通过农产品将其传播给人类。因此，本研究构建了以土壤-生菜-蜗牛为典型结构的农田食物链，添加含有多重耐药质粒RP4的基因工程荧光假单胞菌来追踪其在农田食物链中的传播，并采用不同施肥方式来探究其对农田食物链中ARGs和intl1传播扩散的影响。研究发现，外源假单胞菌可从土壤进入植物并进入蜗牛肠道，且细菌中存在RP4质粒的水平基因转移现象。在构建的食物链不同界面处，添加外源耐药菌对ARGs和intl1的总丰度有不同影响。施肥，尤其是施用粪肥，不仅促进了铜绿假单胞菌的传播和RP4质粒水平的转移，还显著增加了构建的食物链所有界面处ARGs和intl1的总丰度。构建的食物链中主要的ARGs宿主细菌包括变形菌门、拟杆菌门和厚壁菌门，而拟杆菌门中的黄杆菌属是RP4质粒独特的潜在宿主细菌。总之，本研究为通过食物链传播至人体的ARGs风险评估提供了参考，对减少农产品抗生素抗性污染、保障菜篮子安全具有重要现实意义。
