摘要

噬菌体颗粒已成为在不同环境（包括肠道环境）中动员抗药性基因（arg）的潜在元素。本研究旨在检测从粪便中分离的菌株在粪便中产生的噬菌体颗粒中ARGs的含量。在采集前3个月内未接受抗生素治疗或出国旅行的健康人150份粪便样本中，用qPCR法测定了9种ARGs（blaTEM、blaCTX-M-1组、blaCTX-M-9组、blaOXA-48、qnrA、qnrS、mecA、sul1和armA）。怀疑检测到的颗粒物来源于细菌区系，82株大肠埃希菌和肺炎克雷伯菌分离株至少有一个已鉴定的精氨酸（blaTEM，blaCTX-M-1组，blaCTX-M-9组，armA，qnrA，分离了qnrS和sul1），并评估了它们诱导后产生携带这些ARGs的噬菌体颗粒的能力。在150份样本中，72.7%的样本中至少有一个ARG呈阳性，其中blaTEM和blaCTX-M-9组最为普遍和丰富。在82株分离物中，51株（62%）在诱导后的噬菌体片段中相应ARG的拷贝数增加，其中blaTEM、blaCTX-M-1组、blaCTX-M-9组和sul1最为丰富。从分离的噬菌体中进一步纯化并用显微镜观察，其DNA显示ARG水平高达1010个基因拷贝/mL。本研究强调了含有ARG的噬菌体颗粒的丰富性，并表明肠道环境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 (bla_TEM, bla_{CTX-M-1 group}, bla_{CTX-M-9 group}, bla_OXA-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 (bla_TEM, bla_{CTX-M-1 group}, bla_{CTX-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 bla_TEM and bla_{CTX-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 bla_TEM, bla_{CTX-M-1 group}, bla_{CTX-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.