摘要

       噬菌体颗粒已成为可能在不同环境（包括肠道栖息地）中动员抗生素抗性基因 (ARG) 的元素。这项研究旨在确定存在于粪便中的噬菌体颗粒中 ARG 的发生，这些颗粒是从粪便分离的菌株中诱导出来的。 9 个 ARG（blaTEM、blaCTX-M-1 组、blaCTX-M-9 组、blaOXA-48、qnrA、qnrS、mecA、sul1 和 armA）在从健康个体获得的 150 个粪便样本的噬菌体 DNA 部分中通过 qPCR 进行量化样本采集前3个月内未接受抗生素治疗或出国旅行的人。怀疑检测到的颗粒来自菌群，82株大肠杆菌和肺炎克雷伯菌分离株至少具有一个已鉴定的ARG（blaTEM、blaCTX-M-1组、blaCTX-M-9组、armA、qnrA、qnrS和sul1）分离并评估它们在诱导后产生携带这些 ARG 的噬菌体颗粒的能力。在 150 个样本中，72.7% 对至少一种 ARG 呈阳性，其中 blaTEM 和 blaCTX-M-9 组是最普遍和最丰富的。在 82 个分离株中，51 个（62%）在诱导后噬菌体部分中相应 ARG 的拷贝数增加，其中 blaTEM、blaCTX-M-1 组、blaCTX-M-9 组和 sul1 是最多的丰富。从分离物中诱导的噬菌体被进一步纯化并使用显微镜观察，它们的 DNA 显示 ARG 水平高达 1010 基因拷贝/mL。这项研究强调了大量含有 ARG 的噬菌体颗粒，并表明肠道栖息地中的细菌菌株可能是这些颗粒的来源。

       Phage particles have emerged as elements with the potential to mobilise antibiotic resistance genes (ARGs) in different environments, including the intestinal habitat. This study aimed to determine the occurrence of ARGs in phage particles present in faecal matter and induced from strains isolated from faeces. Nine ARGs (blaTEM, blaCTX-M-1 group, blaCTX-M-9 group, blaOXA-48, qnrA, qnrS, mecA, sul1 and armA) were quantified by qPCR in the phage DNA fractions of 150 faecal samples obtained from healthy individuals who had not received antibiotic treatment or travelled abroad in the 3 months prior to sample collection. On the suspicion that the detected particles originated from bacterial flora, 82 Escherichia coli and Klebsiella pneumoniae isolates possessing at least one identified ARG (blaTEM, blaCTX-M-1 group, blaCTX-M-9 group, armA, qnrA, qnrS and sul1) were isolated and their capacity to produce phage particles carrying these ARGs following induction was evaluated. Of 150 samples, 72.7% were positive for at least one ARG, with blaTEM and blaCTX-M-9 group being the most prevalent and abundant. Of the 82 isolates, 51 (62%) showed an increase in the number of copies of the respective ARG in the phage fraction following induction, with blaTEM, blaCTX-M-1 group, blaCTX-M-9 group and sul1 being the most abundant. Phages induced from the isolates were further purified and visualised using microscopy and their DNA showed ARG levels of up to 1010 gene copies/mL. This study highlights the abundance of phage particles harbouring ARGs and indicates that bacterial strains in the intestinal habitat could be source of these particles.

https://www.sciencedirect.com/science/article/abs/pii/S0924857917304314