摘要:目的 对不同地区、不同宿主大肠杆菌O 157 :H 7 分离株进行基因分型。 方法 应用插入序列PCR方法，对反应体系中dNTPs、引物以及镁离子浓度等反应条件进行优化。扩增产物通过琼脂糖凝胶电泳检测和分析。 结果 14株不同来源O 157 :H 7 分离株根据插入序列PCR图谱可分为A、B、C、D四个基因型。不同地区O 157 :H 7 菌株存在不同的基因型;同一地区、毒力基因谱相同的O 157 :H 7 菌株基因型也不相同;不同宿主O 157 :H 7 菌株也存在相同的基因型。 结论 插入序列PCR技术用于大肠杆菌O 157 :H 7 的基因分型，简便、快速、敏感，对大肠杆菌O 157 :H 7 的分子流行病学研究具有重要价值。

    关键词:大肠杆菌O 157 :H 7 基因分型插入序列聚合酶链反应

    Study on the application of insert sequence PCR in genotyping of E.coli O 157 :H 7 .

    GUO Xi-ling，SHI Zhi-yang，WANG hua，et al.

    (Zhejiang Provincial Center for Disease Control and Prevention，Nanjing210009，Zhejiang，P.R.China)

    Abstract:Objectiwe To perform genetic categorization of Ecoli O 157 :H 7 strains acquired from hosts in different districts. Methods IS-PCR was performed and PCR conditions were optimized.Amplification products were analyzed by agarose gel elec-trophoresis. Results A total of14strains of O 157 :H 7 were further categorized as genetic groups A，B，C and D.Both strains from different regions and strains with similar virulence gene profiles in the same region could be further differentiated by IS-PCR ......