【摘要】 目的分析福建省新出现的福氏志贺菌4c血清亚型的毒力基因分布,菌株间的遗传关联度以及基因组的多态性。方法运用PCR扩增技术对17株F4c菌进行ipaH、set1(set1A和set1B)、sen、ial 4种毒力基因的检测,同时运用脉冲肠凝胶电泳(PFGE)技术进行分子分型。结果 ipaH、set1(set1A和set1B)、sen、ial基因阳性的菌株分别占100%、94.12%、82.35%、88.23%;17株F4c菌分为I-IV型不同的毒力基因分布模式,I型是优势模式占76.47%;按100%的相似度,PF-GE有12种型别(P1-P12),不存在集中优势的PFGE型别;根据TENOVER原则,分为3个PFGE群(G1-G3),G1是优势群,占64.71%。结论我省分离的F4c血清亚型的志贺菌大部分菌株具有较强的毒力特征;绝大多数感染患者之间无明显的传播关系,不同克隆群在传播中存在着集中趋势,提示某一克隆群的F4c菌有可能逐步演变成为我省主要且稳定的福氏志贺菌流行菌株。更多还原

【Abstract】 Shigella species remain the leading bacterial etiological agents of gastrointestinal diseases worldwide.To investigate virulence gene distribution,genetic relationship and genomic diversity of S.flexneri 4C strains from Fujian Province,four virulence genes ipaH,set1(set1A and set1B),sen and ial were detected by PCR for 17 S.flexneri 4C isolates.Molecular typing of these strains was performed with pulsed-field gel electrophoresis(PFGE).It was revealed that positive rates for the ipaH,set1(set1A and set1B),sen and ial gene were 100%,94.12%,82.35% and 88.23%,respectively.Four distribution modes of virulence genes were observed in the 17 strains,while 76.47% belonged to type I,the dominant mode.Twelve PFGE patterns(P1-P12) were detected according to 100% identity,and no clustered or dominant pattern was observed.However,three PFGE groups(G1-G3) were identified based on the TENOVER principle,among which Group 1 of 64.71% was the dominant.These results indicated that most S.flexneri 4C strains in Fujian were virulent.The fact that no obvious transmission chain was observed among most patients,whereas the clustering tendency of diverse circulating clones occurred,suggesting that certain clones of S.flexneri 4C might gradually develop as the main and stable S.flexneri strains in Fujian.更多还原