College of Veterinary Medicine, National Risk Assessment Laboratory for Antimicrobial Resistant of Microorganisms in Animals, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China; College of Animal Science and Technology, State International Joint Research Center for Animal Health Breeding, Shihezi University, Shihezi 832003, China.
Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China.
Environ Int. 2024 Sep;191:108974. doi: 10.1016/j.envint.2024.108974. Epub 2024 Aug 21.
In 2018, China implemented the Veterinary Antimicrobial Use Reduction Action to curb the rapid development of antibiotic resistance (AR). However, the AR-related pollutions in animal farms after the reduction policy has been poorly investigated. Here, we performed a comprehensive investigation combining UPLC-MS/MS, metagenomic, and bacterial genomic analyses in eight representative large-scale chicken farms in Guangdong, China. Our results showed that antibiotics and ARGs contaminations were more severe in broiler farms than in layer farms. Notably, diverse tet(X) variants were prevalent in the chicken farms. These tet(X)s was carried by diverse E. coli lineages and obviously correlated with ISCR2 and IS1B transposases. The resistomes in chicken farms was significantly correlated with microbial community, and multiple factor analyses indicated that the joint effect of antibiotics-microbial community-MGEs was the most dominant driver of ARGs. Host tracking identified a variety of ARG bacterial hosts and the co-occurrence of ARGs-MRGs-MGEs. Source tracking indicated that the inherent component represented the main feature of resistomes in different hosts, while ARG transfer between the chicken gut and farm environments were frequent. A multiperspective evaluation of AR risk revealed that the early effect of antibiotic reduction was exhibited by the mitigation of maximum level of risky ARGs, prevalence of environmental AR pathogens, and HGT potential of ARGs mediated by phage structures. Overall, our findings provide insights into the antibiotic and ARG profiles in large-scale chicken farms with different rearing strategies and demonstrate a preliminary view of the performance of antibiotic reduction actions in China.
2018 年，中国实施了《兽医抗菌药物使用减量化行动》，以遏制抗生素耐药性（AR）的快速发展。然而，在减少政策实施后，动物养殖场中与 AR 相关的污染情况却鲜有调查。在这里，我们在中国广东的 8 个具有代表性的大型养鸡场中，结合 UPLC-MS/MS、宏基因组和细菌基因组分析进行了全面调查。结果表明，抗生素和 ARG 污染在肉鸡养殖场比蛋鸡养殖场更为严重。值得注意的是，不同的 tet(X) 变体在鸡场中广泛存在。这些 tet(X) 由不同的大肠杆菌谱系携带，与 ISCR2 和 IS1B 转座酶明显相关。鸡场中的耐药组与微生物群落显著相关，多因素分析表明抗生素-微生物群落-MGEs 的共同作用是 ARGs 的最主要驱动因素。宿主追踪确定了多种 ARG 细菌宿主，以及 ARGs-MRGs-MGEs 的共同发生。来源追踪表明，固有成分是不同宿主耐药组的主要特征，而鸡肠道和农场环境之间的 ARG 转移则较为频繁。对 AR 风险的多角度评估表明，抗生素减少的早期效果表现为高风险 ARGs 的最大水平的缓解、环境 AR 病原体的流行以及噬菌体结构介导的 ARG 的 HGT 潜力。总的来说，我们的研究结果提供了对不同饲养策略下大型养鸡场中抗生素和 ARG 谱的深入了解，并初步展示了中国抗生素减少行动的效果。
