福建省非典型 O1群埃尔托型霍乱弧菌的研究  

Genetic diversities in atypical El Tor strains fromVibrio cholerae O1 serogroup in Fujian Province,China

作　　者：陈爱平[1,2,3] 郑恩惠[1] 李曲文[1] 徐海滨[1] 杨劲松[1] 王灵岚[1] 郑金凤[1] 严延生[1] 

机构地区：[1]福建省疾病预防控制中心,福州350001 [2]福建省人兽共患病研究重点实验室,福州350001 [3]福建医科大学公共卫生学院教学基地,福州350001

出　　处：《中国人兽共患病学报》2014年第8期787-792,共6页Chinese Journal of Zoonoses

基　　金：福建省自然科学基金(No.2014J01282)资助~~

摘　　要：目的探索非典型O1群埃尔托型霍乱弧菌在福建省1962-2005年霍乱菌株中的存在及其意义。方法选择1962-2005年代表性霍乱菌株69株(稻叶21、小川48),运用PCR技术进行ctxB、tcpA、rstR、hlyA各毒力因子的古典型(Cl)和埃尔托型(El)基因的扩增;同时对部分菌株的ctxB和rstR基因的序列进行测定和比对;分析福建省O1群埃尔托型霍乱弧菌(EVC)中非典型菌株出现的时间和存在意义。结果 1962年福建省分离的O1群EVC菌株中携带有ctxB-Cl、tcpA-Cl、hlyA-Cl基因;rstR-Cl基因仅在1994-2000年的霍乱菌株中检出。序列比对结果发现ctxB基因出现新的204位碱基突变位点(T→G);同时报道两种新的ctxB基因型别(10和11),且发现存在于同一个菌株中;ctxB基因型11的115位碱基为C,表现为古典型ctxB位点特征,203位碱基为T,表现为埃尔托型ctxB位点特征。结论福建省在1962年的O1群EVC菌株中就出现杂合有ctxB-Cl、tcpA-Cl、hlyA-Cl基因的非典型EVC菌株,是迄今为止报道出现非典型EVC最早的年代;1994年以后出现整合有rstR-Cl基因的非典型EVC菌株。另外,在福建省O1群EVC中存在国内外未曾报道的新的ctxB碱基突变位点和ctxB基因型别;同时在同一菌株中存在不同的ctxB基因型别杂合形式;ctxB序列也存在不同生物型别的特异位点组合形式。福建省O1群EVC表现为独特的地方性分子特征。The emergence of atypical El Tor strains from V .cholerae in South Asia and Africa has been attributed to several outbreaks in recent decades ,however ,backgrounds of such strains in China remain exclusive .In this study ,PCR am-plification of both El Tor and classical alleles for ctxB ,tcpA ,rstR and hlyA genes was attempted in sixty-nine El Tor isolates from Fujian between 1962 to 2005 ,in addition ,some amplicons were sequence-analyzed .Thus ,the time point of atypical EVC strains in Fujian was determined ,genetic diversities of such strains were investigated .It was revealed that ctxB-Cl ,tcpA-Cl and hlyA genes were detected in O1 serogroup EVC isolates from Fujian since 1962 .Although rstR-Cl gene was solely detected in isolates between 1994 to 2000 .It was indicated by sequence analysis that atypical EVC strains from Fujian possessed a novel T→G mutation at residual 204 of the ctxB gene .Remarkably ,two novel ctxB genotypes （ctxB-10 and ctxB-11） were identified in one strain .The residual 115-C of ctxB in ctxB-11 showed characteristics of ctxB-Cl ,however ,its residual 203-T demonstra-ted characteristics of ctxB-El .This observation implied that it was common in O1 serogroup EVC strains from Fujian hybrid-ized with classical alleles since 1962 ,which would be the earliest time-point for the emergence of atypical El Tor strains hitherto in literature .Emergence of atypical El Tor strains harboring rstR-Cl in Fujian occurred since 1994 .Meanwhile ,novel mutation sites and ctxB genotypes were observed in Fujian isolates ,including diverse combination of ctxB genotypes in one strain and combination of biotype-specific sites in ctxB sequences .In summary ,molecular characterization of O 1 serogroup EVC strains from Fujian was unique and geography-associated .

关 键 词：霍乱弧菌 毒力基因 等位基因 序列分析 

分 类 号：R378.3[医药卫生—病原生物学]