摘要

       抗生素抗性进入土壤的主要途径是通过施用牲畜粪便。然而，抗生素抗性细菌（ARB）和抗生素抗性基因（ARGs）是否会随着粪肥和粪肥产品的应用而持续存在并传播到蔬菜中，目前尚不清楚。本研究评估了蔬菜生产链（从粪便到生物堆肥、土壤和蔬菜）中的 7 种培养 ARB、221 个 ARG 亚型和 3 个转座子基因。结果表明，有氧堆肥后至少 80% 的 ARB、ARG 和转座子基因被去除。然而，好氧堆肥并未降低猪粪和鸡粪中 ARGs 的多样性。在有氧堆肥过程中，共有 19 种 ARG 亚型仍然存在。与温度-嗜热阶段相比，对红霉素耐药的细菌数量、ARGs和IS613的相对丰度在降温阶段增加了1.7-4.9倍。生物堆肥的直接应用为小白菜引入了 11 种 ARGs 亚型，但这些 ARGs 不存在于生物堆肥改良的土壤中。在生物堆肥改良的土壤中也检测到转座子基因 tnpA，但令人惊讶的是在对照蔬菜中发现了转座子基因 tnpA。这表明转座子基因是小白菜内在的。细菌群落分析和网络分析显示，在蔬菜生产链中存在携带tetO、tetW ermB和tnpA的特里斯孢杆菌属，这可能对后续生产产生潜在风险。我们的研究阐明了蔬菜生产链中抗生素耐药性的持续存在和蔓延，这有助于管理粪便来源中抗生素耐药性引起的生态风险。

       The main avenue in which antibiotic resistance enters soils is through the application of livestock manure. However, whether antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) persist and spread to vegetables with the application of manure and manure products is still unclear. This study assessed seven kinds of cultured ARB, 221 ARGs subtypes and three transposon genes in the vegetable production chain (from manure to biocompost, soils and vegetables). Results showed that at least 80% of ARB, ARGs and transposon genes were removed after aerobic composting. However, aerobic composting did not reduce the diversity of ARGs in pig and chicken manure. A total of 19 ARGs subtypes still persisted during aerobic composting. Compared to the temperature-thermophilic stage, the number of bacteria resistant to erythromycin, the relative abundance of ARGs and IS613 increased 1.7–4.9 times at the temperature-decreasing stage. Direct application of biocompost introduced 11 ARGs subtypes to pakchoi, but these ARGs did not present in biocompost-amended soil. A transposon gene tnpA was also detected in the biocompost-amended soil, but surprisingly was found in the control vegetable. This demonstrated that the transposon gene is intrinsic in pakchoi. Bacterial community analysis and network analysis revealed that a specific genus Terrisporobacter carrying tetO, tetW ermB and tnpA persisted in the vegetable production chain, which may generate a potential risk in the following production. Our study illuminates the persistence and spreading of antibiotic resistance in the vegetable production chain which could help manage the ecological risks arising from antibiotic resistance in manure sources.

https://www.sciencedirect.com/science/article/abs/pii/S004896971932649X