Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 272, CH-8057 Zurich, Switzerland.
State Laboratory of Basel-Stadt, Kannenfeldstrasse 2, 4056 Basel, Switzerland.
Int J Antimicrob Agents. 2017 Sep;50(3):436-440. doi: 10.1016/j.ijantimicag.2017.04.017. Epub 2017 Jun 28.
The aim of this study was to evaluate wastewater for carbapenemase-producing Enterobacteriaceae (CPE) and 16S rRNA methylase-producing Gram-negative bacteria (MPB) and to assess their occurrence following wastewater treatment. Wastewater samples were collected between June 2015 and March 2016 in the sewage network of the city of Basel (Switzerland) from sites located before and after influx of wastewater from the hospital into the sewage network. Samples were also obtained from the influent and effluent of the receiving wastewater treatment plant. Samples were screened for CPE and MPB using selective media. Escherichia coli and Klebsiella pneumoniae were typed by multilocus sequence typing (MLST). Carbapenemase and 16S rRNA methylase genes were identified by PCR and sequencing. Resistance profiles were determined by the disk diffusion test and Etest. The occurrence of CPE and MPB was increased downstream of hospital wastewater influx. Of 49 CPE isolates, 9 belonged to OXA-48-producing E. coli clone D:ST38, 7 were OXA-48-producing Citrobacter freundii, and 6 were KPC-2- or OXA-48-producing K. pneumoniae belonging to clonal complex 258. NDM (NDM-1, -5 and -9) and VIM (VIM-1) producers were detected sporadically. MPB included ArmA- and RmtB-producing E. coli and Citrobacter spp. Isolates corresponding to strains from wastewater were detected in the effluent of the treatment plant. Conclusively, CPE and MPB, predominantly OXA-48-producing Enterobacteriaceae, are readily detected in wastewater, survive wastewater treatment and are released into the aquatic environment. OXA-48-producers may represent an emerging threat to public health and environmental integrity.
本研究旨在评估污水中碳青霉烯酶产生肠杆菌科（CPE）和 16S rRNA 甲基酶产生革兰氏阴性菌（MPB）的情况，并评估其在废水处理后的发生情况。2015 年 6 月至 2016 年 3 月，在瑞士巴塞尔市的污水管网中，从医院污水进入污水管网前和后的位置采集污水样本。还从接收污水处理厂的进水和出水处采集样本。使用选择性培养基筛选 CPE 和 MPB。通过多位点序列分型（MLST）对大肠埃希菌和肺炎克雷伯菌进行分型。通过 PCR 和测序鉴定碳青霉烯酶和 16S rRNA 甲基酶基因。通过圆盘扩散试验和 Etest 确定耐药谱。在医院污水流入的下游，CPE 和 MPB 的发生增加。在 49 株 CPE 分离株中，9 株属于产 OXA-48 的大肠埃希菌克隆 D:ST38，7 株为产 OXA-48 的弗氏柠檬酸杆菌，6 株为产 KPC-2 或 OXA-48 的肺炎克雷伯菌，属于克隆复合体 258。偶尔检测到 NDM（NDM-1、-5 和 -9）和 VIM（VIM-1）产生菌。MPB 包括产 ArmA 和 RmtB 的大肠埃希菌和柠檬酸杆菌属。在处理厂的出水处检测到与废水来源菌株相对应的分离株。总之，CPE 和 MPB，主要是产 OXA-48 的肠杆菌科，很容易在废水中检测到，能够在废水处理中存活，并释放到水生态环境中。产 OXA-48 的菌株可能对公共卫生和环境完整性构成新的威胁。
