广东省食源性副溶血弧菌表型特征与分型比较研究

目的 了解广东省食源性副溶血弧菌的表型特征,并对其分型进行综合比较.方法 对分离自广东省水产品和食物中毒的74株副溶血弧菌分离株进行生化鉴定、药敏试验、耐热直接溶血素(tdh)和耐热直接溶血素相关溶血素(trh)毒力基因的PCR检测.并对副溶血弧菌进行血清分型、核糖体基因分型(Ribotyping)和脉冲场凝胶电泳(PFGE)分型,应用BioNumerics软件对不同来源、时间和地点的分离株进行比对,分析菌株之间的相关性.结果 副溶血弧菌除对氯霉素100.00％敏感外,对其余13种抗生素均有不同程度的耐药.tdh阳性率为24.32％、trh阳性率为4.05％.74株副溶血弧菌分为26种血清型,O5:K17和O2:K28型为水产品分离株的优势血清型,O3:K6型为食物中毒分离株的优势血清型.74株副溶血弧菌分为62个核糖体型、67个PFGE型,表现出较大的遗传多样性.结论 广东省大部分食物中毒副溶血弧菌分离株携带tdh毒力基因.3种分型方法中,PFGE的分辨率最高,Ribotyping居中,血清分型最低,3种方法相结合可提高分辨率.

Comparative study on the phenotypic characteristics and molecular typing of foodborne Vibrio parahaemolyticus in Guangdong province

Objective To understand the phenotypic characteristics of foodbome Vibrio parahaemolyticus in Guangdong province through carrying out a comprehensive comparison including pulse field gel electrophoresis,ribotyping and serotyping.Methods 74 different Vibrio parahaemolyticus strains isolated from seafood and cases due to food poisoning in Guangdong province were under serotyping and susceptibility testing,in addition to the testing of direct heat hemolysin(tdh)and the heat hemolysin-related hemolysin hormone(trh)via PCR.Ribosomal genotyping(ribotyping)with EcoR Ⅰ restriction enzyme was utilized on 74 different Vibrio parahaemolyticus isolates,whereas pulsed-field gel electrophoresis(PFGE)with the Not Ⅰ restriction enzyme was used on 74 different Vibrio parahaemolyticus isolates.BioNumerics software was used to compare the isolates from different sources,times and places in order to elicit the correlation between different strains.Results Although Vibrio parahaemolyticus was 100.00％ sensitive to chloramphenicol,it still presented different levels of resistance against 13 other antibiotics.Among the 74 different strains of Vibrio parahaemolyticus under testing,24.32％ showed positive for the tdh virulence gene,whereas 4.05％ positive for trh.74 different Vibrio parahaemolyticus strains were found to belong to 26 serotypes,where the O5:K17 and O2:K28 serotypes were dominant in those isolates that causing seafood-poisoning.The O3:K6 serotype was found to be the dominant of those isolates that causing food-poisoning.Based on ribosomal genotyping,the 74 Vibrio parahaemolyticus isolates were divided into 62 different ribotypes,whereas the 74 strains of Vibrio parahaemolyticus were divided into 67 different PFGE types,thus exhibiting considerable genetic diversities of the strains.Conclusion Majority of the isolates causing food-poisoning carried tdh virulence gene.PFGE was shown to have the highest resolution,followed by ribotyping with serotyping being the lowest,where the combination of the three could improve the resolution.