摘要

    本研究调查了35和55粪肥厌氧消化（AD）过程中抗生素（磺酰胺和四环素）耐药基因（ARGs）和耐药细菌（ARB）的变化，并探讨了ARGs的变化机理。 AD持续60天，在嗜热温度下AD后，五个ARG和intI1的丰度均降低，而在中温温度下仅降低了一半。在第10、30和60天，在选择性培养基上筛选磺酰胺和四环素ARB。在嗜热性AD期间，ARB数量每克干粪肥减少4-log CFU，但在中温温度下仅减少约1-log CFU。但是，ARB组成分析表明，在任一温度下，均未观察到已鉴定出的ARB种类的明显减少。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都被各种宿主所携带，并且ARG与细菌物种之间没有明确的联系。另外，通过与培养方法鉴定的宿主进行比较，基于ARG和细菌群落之间相关性分析的宿主预测结果被证明是不可靠的。总体而言，这些发现表明ARB与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