摘要

       本研究调查了35 ℃和55 ℃粪便厌氧消化（AD）过程中抗生素（磺胺类和四环素）抗性基因（ARGs）和抗性细菌（ARB）的变异，并讨论了ARGs变异的机制。 AD持续60天，AD后5个ARGs和intI1在高温下丰度下降，而在中温下仅减少一半。在第 10、30 和 60 天，在选择性培养基上筛选磺胺和四环素 ARB。在嗜热 AD 期间，ARB 数量每克干粪减少 4-log CFU，但在中温下仅减少约 1-log CFU。然而，ARB 成分分析表明，在任一温度下，均未观察到已识别 ARB 种类的显着减少。此外，随机选择了 72 个 ARB 克隆来检测它们所携带的 ARG，结果表明每个 ARG 都被不同的宿主所携带，ARG 与细菌物种之间不存在明确的联系。此外，通过与通过培养方法鉴定的宿主进行比较，证明基于ARGs与细菌群落相关性分析的宿主预测结果是不可靠的。总体而言，这些发现表明 ARB 和 ARG 之间的关系错综复杂。

       This study investigated the variations in antibiotic (sulfonamide and tetracycline) resistance genes (ARGs) and resistant bacteria (ARB) during manure anaerobic digestion (AD) at 35 ℃ and 55 ℃, and discussed the mechanisms of variations in ARGs. The AD lasted for 60 days, five ARGs and intI1 each decreased in abundance after AD at the thermophilic temperature, while only half decreased at the mesophilic temperature. On days 10, 30, and 60, sulfonamide and tetracycline ARB were screened on selective media. During thermophilic AD, ARB numbers reduced by 4-log CFUs per gram dry manure, but only by approximately 1-log CFU at the mesophilic temperature. However, ARB composition analysis showed that at either temperature, no significant reduction in identified ARB species was observed. Furthermore, 72 ARB clones were randomly selected to detect the ARGs they harbored, and the results showed that each ARG was harbored by various hosts, and no definitive link existed between ARGs and bacterial species. In addition, by comparison with the identified host by culture method, the host prediction results based on the correlation analysis between ARGs and the bacterial community was proven to be unreliable. Overall, these findings indicated that relationships between ARB and ARGs were intricate.

https://www.sciencedirect.com/science/article/abs/pii/S0304389419313871