摘要
目的对武汉市某区一起疑似产气荚膜梭菌引起的食物中毒事件进行分子分型溯源及耐药特征性分析。方法采用FIlm Array TM检测系统和多重荧光定量PCR方法对中毒事件所涉样本进行病原菌初筛,根据初筛结果进行细菌分离培养和质谱鉴定分析,采用荧光PCR对分离菌株进行产气荚膜梭菌6种毒力基因检测,基于全基因组测序结果分析其毒力基因、耐药基因及全基因组单核苷酸多态性遗传进化分析(wgSNPs),采用琼脂稀释法进行抗生素敏感性试验。结果共分离到10株产荚膜梭菌,其中8株来自7份肛拭子样本,1株来自粪便样本,1株来自食品样本。可疑食品产气荚膜梭菌计数为7.8×10^(6) CFU/g。10株产气荚膜分离菌株均检出plc(a)毒素基因,未检出cpe等其他5种毒素基因,证实均为A型菌产气荚膜梭菌。所有菌株对克林霉素100%耐药,对万古霉素、头孢西丁、美罗培南等抗生素几乎完全敏感。10株产气荚膜梭菌均携带tetB(P)、tetA(P)和mprF等耐药基因,其次是ermQ(70%)、ant(6)-Ib(10%)以及LnuP(10%)。wgSNPs遗传进化分析显示4株暴发菌株聚成一簇,与可疑食品来源株同属一个独立的亚分支,亲缘关系较近。结论此次食物中毒事件可能是由被产气荚膜梭菌污染的手撕鸡所致,菌株未出现多重耐药现象,但均对克林霉素耐药,需引起临床重视。
This study was aimed at tracing the molecular typing and drug resistance characteristics of a suspected food poisoning event caused by Clostridium perfringens in a district of Wuhan City.The FilmArray detection system and multiple fluorescence quantitative PCR methods were used to rapidly screen for pathogens in samples from the poisoning event.According to the initial screening results,bacteria were isolated,cultured,and identified by mass spectrometry.Fluorescence PCR was used to detect six virulence genes of the isolated Clostridium perfringens strains.On the basis of whole genome sequencing results,we conducted virulence genes,resistance genes,and whole genome single nucleotide polymorphism genetic evolution(wgSNPs)analyses.Antibiotic sensitivity testing was conducted with the agar dilution method.A total of ten strains of Clostridium perfringens were isolated,including eight strains from seven anal swab samples,one strain from fecal samples,and one strain from food samples.Food with suspected contamination had a Clostridium perfringens count of 7.8×10^(6) CFU/g.The PLC(a)toxin gene was detected in all ten gas producing capsule isolation strains,but no other 5 tox-in genes such as CPE were detected,thus confirming that all were type A bacteria producing capsule Clostridium.All strains were 100%resistant to clindamycin and almost completely sensitive to antibiotics such as vancomycin,cefoxitin,and meropenem.Ten strains of Clostridium perfringens carried resistance genes such as tetB(P),tetA(P),and mprF,followed by ermQ(70%),ant(6)-Ib(10%),and LnuP(10%).Genetic evolution analysis of wgSNPs indicated that the four outbreak strains clustered together and belonged to an independent subbranch with the suspected food source strains,thus indicating close genetic relationships.In conclusion,this food poisoning incident might have been be caused by hand torn chickens contaminated with Clostridium perfringens,and the molecular types of the strains revealed high genetic diversity.No multiple drug resistance was observed,but all strains were resistant to clindamycin,an aspect requiring further clinical attention.
作者
余树坤
崔紫妍
刘浪
谭雅心
崔洲莹
陶志阳
YU Shu-kun;CUI Zi-yan;LIU Lang;TAN Ya-xin;CUI Zhou-ying;TAO Zhi-yang(Disease Prevention and Control Center of Dongxihu District,Wuhan 430040,China)
出处
《中国人兽共患病学报》
北大核心
2025年第1期61-66,共6页
Chinese Journal of Zoonoses
基金
武汉中青年医学骨干人才培养工程(No.武卫通〔2020〕55号)。
关键词
产气荚膜梭菌
多重PCR初筛
全基因组测序
耐药基因
食物中毒
clostridium perfringens
multiple PCR initial screening
whole genome sequencing
drug resistance genes
food poisoning
