霍乱弧菌毒力相关基因ctxA B、zot、cri特征分析研究

目的在分子水平上了解霍乱弧菌毒力基因的分布特点和变迁及其流行规律。方法采用PCR方法对1964—2008年天津市疾病预防与控制中心分离、保存的176株霍乱弧菌的CTXΦ基因元件中的ctxAB、zot基因,TLC因子中的cri基因进行检测。结果176株霍乱弧菌中,有131株携带CTXΦ遗传单元中的ctxAB、zot基因,阳性率分别为72.72%(128/176),73.30%(129/176),TLC因子中cri基因的阳性率为40.34%(71/176)。在1964—1996年间分离的O1群霍乱弧菌中,有69.00%(69/100株)携带cri基因,而1998—2008年间分离的霍乱弧菌中cri基因的阳性率仅为1.33%(1/75)。1株O139群霍乱弧菌ctxAB、zot、cri均呈阳性。结论毒力相关基因检测能反映不同年代菌株间的分子特征,对于霍乱的分子流行病学研究具有重要意义。

Study on Characteristics of Virulence-related Gene ctrAB,zot,cri of Vibrio cholerae

Objective To understand the distribution, variation and prevalence of virulence-related gene of the V.cholerae at the molecular level. Methods PCR technique was applied to detect ctxA B, and zot gene of CTXφ genetic element,cri gene of TLC cluster of the 176 strains of V.cholerae isolated from 1964 to 2008. Results One hundred and thirty-one strains of V.cholerae carry ctxAB and zot of CTXφ genetic element in 176 strains,the positive rates were 72.72%(128/176 strain) and 73.30%(129/176 strain) respectively. 69.00%(69/100 strain) of V.cholerae O1 strains isolated from 1964 to 1996 carried cri gene, however the rate was only 1.33%(1/75) in the strains isolated from 1998 to 2008. ctxAB, zot and cri in V.cholerae 0139 were all positive. Conclusion Detection of virulence-related genes can reflect the molecular characteristics of strains,and it is important to the molecular epidemiology of V.cholerae research.