广州腹泻患者艰难梭菌的分离鉴定、毒素类型和MLST分型

The isolation and identification,toxins types and MLST typing of Clostridium difficile from patients with diarrhea in Guangzhou

目的了解广州地区腹泻患者中艰难梭菌(CD)的分布、毒素类型和基因型。方法 PCR直接检测粪便中CD tpi基因、毒素基因tcd A、tcd B和cdt A/cdt B。对tpi阳性的标本富集芽孢后,进行厌氧分离培养CD及分子鉴定,同时对菌株进行MLST分型。结果 467份标本的tpi基因阳性率为6.2%(29/467);29份tpi阳性标本的CD培养阳性率为75.9%(22/29);22株CD可分成9种不同的ST型,其中ST54、ST3为相对优势型别,未检测到高产毒株ST1和ST11。结论目前广州地区腹泻患者中CD感染发病率不高,感染多为散发,未发现CD高产毒菌株和暴发流行。对于腹泻患者粪便标本,先采用PCR检测CD种特异性tpi,再富集芽孢厌氧培养和鉴定CD的方法,是一种经济、实用的实验室检测方法。

Objective To realize the distribution,toxin＇s type and genetypes of Clostridium difficile（ CD） from patients with diarrhea in Guangzhou. Methods PCR method was used to detect the CD gene tpi and toxin gene tcd A,tcd B,cdt A / cdt B. The CD spores of tpi positive samples were enriched and incubated in anaerobic environment,and CD isolates were typed by MLST.Results The positive rate of CD gene tpi was 6. 2%（ 29 /467） in 467 stool samples. The CD isolation rate of 29 positive stool specimens with gene tpi was 75. 9%（ 22 /29）. 22 CD strains can be divided into 9 different ST types,ST54 and ST3 were relatively dominant types. ST11 and ST1 of hypervirulent CD strains were not detected. Conclusion The incidence of CD infection is not high,CD infection is sporadic,CD infection＇s outbreak and the hypervirulent CD strain have not be found till now in patients with diarrhea in Guangzhou. As for the stool specimens from the patients with diarrhea,the CD gene tpi is detected by PCR at first,then CD spores are enriched and cultured in anaerobic environment for CD isolation and identification,which is a kind of economic and practical laboratory monitoring method for CD infection.