应用多重PCR法鉴定产志贺样毒素大肠杆菌毒力基因

目的：从各种来源的标本中快速鉴定STEC毒力基因，并了解其在菌株中的分布情况．方法：采用多重PCR的方法鉴定STEC的特征性毒力因子stx1，six2，eaeA和hlyA．结果：各种标本中鉴定出产志贺毒素的大肠杆菌共46株，38株(82．6％)携带stx1基因，30株(65．2％)具有six2基因，22株(47．8％)同时检测到2种基因．36株(78．3％)检测到hlyA基因，24株(52．2％)有eaeA基因．4种毒力基因即six1 stx2 eaeA hlyA的有19株(41．3％)，而且血清型均为O157．结论：产志贺样毒素大肠埃希菌毒力基因图谱是一个重要的分子流行病学标志，应用多重PCR可简便、快速、敏感、特异性地鉴定出STEC的特征性毒力基因，并依照毒力基因存在情况判定其致病性能．

Identification of Virulence Genes in Shiga toxigenic Escherichia coli by Using Multiplex PCR

Objective To identify Shiga toxigenic Escherichia coli rapidly and to understand the distribution of putative virulence factors in STEC. Methods The multiplex PCR(mPCR) protocol was used to detect marker genes. PCR products were analysed by gel electrophoresis in 2% gels stained with ethidium bromide, visualized with u. v. illumination, and imaged with the UV WHITE-2020D documentation system. Results A total 46 isolates of Shiga toiigenic Escherichia coli were detected, 38 isolates(82. 6% )carried stx1 gene, 30 (65.2%)carried stx2 gene, 22(47.8% )were detected stxj and stx2 simultaneously, 36(78.3%) carried hlyA gene, 24(52. 2% )carried eaeA gene. Four kinds of virulence factors existed in 19 isolates(41. 3% ), and all were O157 serotype. Conclusion Since virulence gene pattern of STEC is an important molecular epidemiological marker, it can provide the Information for epidemiologic studies, and explore the pathogenicity of STEC. For virulence genes detection, PCR seems to be a simple, rapid, sensitive and specific method.