中文摘要：

目的分析广东霍乱弧菌（VC）代表菌株主要毒力基因和管家基因序列。方法PCR扩增霍乱弧菌的主要毒力基因（ctxAB和tcpA）和管家基因（dnaE、hlyA、mdh和recA）、基因测序、对序列进行生物信息学分析。结果不同年代分离的2株埃尔托型（EVC）产毒株和1株0139群VC产毒株的主要毒力基因序列与国内外相关报告比较，ctxA基因及推测的氨基酸序列的同源性分别为99．7％～100％和98．8％～100％．ctxB基因及推测的氨基酸序列的同源性分别为98．8％～100％和96．8％～100％，tcpA基因序列与EVC国际标准株N16961 100％同源。3株产毒株的dnaE、hlyA、mdh和recA基因序列同源性分别为99．8％～100％，100％，99．5％～99．8％和100％，氨基酸序列同源性分别为100％．100％，98．5％～99．3％和100％；3株产毒株和O139群VC非产毒株的管家基因序列同源性分别为97．0％～97．2％，91．8％，94．1％～94．4％，96．9％，氨基酸序列同源性分别为100％，94．6％，94．3％～98．5％和99．7％。结论广东省不同年代EVC产毒株和O139群VC产毒株的群体遗传学关系高度密切，而与O139群VC非产毒株较远，O139群VC产毒株可能起源于EVC产毒株。

英文摘要：

Objective To analyse the sequences of important toxic genes and housekeeping genes of Vibrio cholerae strains isolated from Guangdong province. Methods Toxic genes（ctxAB and tcpA）, and housekeeping genes（dnaE, hlyA, mdh and recA）of Vibrio cholerae were obtained by PCR, sequenced and analysed. Results Toxic genes of 2 toxic EVC strains and 1 toxic O139 VC strain were analysed with those reported by others. The identities of ctxA and CtxA were 99.7 % - 100 % and 98.8 % - 100 % . The identities of ctxB and CtxB were 98.8 % - 100 % and 96.8 % - 100 %. The identity of tcpA of 3 toxic strains was 100%, and sequences of tcpA were the same as that of international standard EVC （N16961）. The identities of dnaE, hlyA, mdh, and recA of 3 toxic VC strains were 99.8% - 100%, 100%, 99.5% - 99.8%,and 100%. The identities of DnaE, HIyA, Mdh, and RecA of 3 toxic VC strains were 100%, 100%, 98.5% - 99.3 %, and 100 % . The identities of dnaE, hlyA, mdh, and recA of 3 toxic VC strains and 1 non-toxic O139 VC strain were 97.0 % - 97.2 %, 91.8 %, 94.1% - 94.4 %, and 96.9 %. The identities of DnaE, HlyA, Mdh, and RecA of 3 toxic VC strains and 1 non-toxic O139 VC strain were 100 %, 94.6 %, 94.3 % - 98.5 %, and 99.7 %. Conclusion Toxic EVC strains and toxic O139 VC strain isolated from Guangdong province are very closely related and there has been a high of recombination in their evolution.