肠道细菌基因间重复序列基因分型方法研究副溶血性弧菌的基因多态性

Study of gene polymorphism of Vibrio parahaemolyticus based on enterobacterial repetitive intergenic consensus sequences

目的采用肠道细菌基因间重复序列（enterobacterial repetitive intergenic consensus,，ERIC）基因分型技术对副溶血性弧菌进行分型，评估其基因多态性，探讨其在鉴别该菌散发和暴发中的应用。方法采用ERIC-PCR分型方法对187例分离自患者、海产品和环境中的副溶血性弧菌基因组模板进行扩增，根据PCR产物中不同产物片段组合模式获得基因型，采用进化树分析软件直观评价不同基因型的相似性，并根据离散程度分为不同的族，同时进行血清分型。结果187例菌株可获得产物长度160—2780bp共16种大小不同的PCR产物片段，所有菌株根据扩增片段分布可分为59种基因指纹模式，通过进化树软件可分为12族，血清分型结果表明03：K6为86％（161／187），02、04和012占4％（8／187），10％（18／187）无法分型。结论ERIC—PCR分型结果表明，我国分离的副溶血性弧菌具有较高基因多态性，ERIC—PCR具有高分辨力，可用于快速基因分型。

Objective To evaluate the genotype polymorphism of V. parahaemolyticus using enterobacterial repetitive intergenic consensus （ERIC） -PCR and explore its application in distinguishing the sporadic or outbreak cases of V. parahaemolyticus. Methods One hundred and eighty-seven samples of V. parahaemolyticus isolated from patients, seafood, marine and estuarine environments in Ningbo city were typed with both anti-sera and ERIC-PCR. The ERIC-PCR typing results were analyzed with cluster analysis method to evaluate the variation in ERIC sequences of V. parahaemolyticus. Results Sixteen different sizes of DNA bands varying from 160 bp to 2780 bp were detected in 187 isolates by ERIC-PCR. These samples were grouped into 59 fingerprint patterns according to the distribution of amplified DNA bands, which were classified into 12 different types with cluster analysis. 03 ：K6 was the most popular serotype accounting for 86% （161/187）. About 4% （8/187） of the samples were other serotypes （02, 04, and O12） while about 10% （18/187） could not be typed by antisera. Conclusion Our study showed that ERIC-PCR is a suitable rapid typing method for V. parahaemolyticus with highly discriminative ability and that V. parahae-molyticus in China is genomically diversified concerning ERIC sequences.