Analysis on plasmid DNA polymorphism of S.flexneri 2a from different areas

  Objective   To identify homogenous clones of S1flexneri 2a, using gene distribution polymorphism of plasmid DNA of S.flexneri 2a.

  Methods   93 strains of S.flexneri 2a isolated from different areas at different time were detected by plasmid profiles and restriction endonuclease profiles to identify genetic type and homogenous clones of S.flexneri 2a.

  Results   Plasmid DNA analysis showed that the 93 strains of S.flexneri 2a isolated from different areas at different time possessed 13 different plasmid profile features (PLT1/-PLT13 type)and 15 different restriction endonuclease profile features(ReT1-ReT15 type).

  Conclusion   The 93 strains of S.flexneri 2a isolates obtained from different areas and at different time fell into 15 subclonial clusters.Although these isolates shared a common predominant clonial cluster(PLT1/ReT1 type)in Hainan, Jiangmen, Bengbu, Hefei, Anqing.The same phenotypingS.flexneri 2a was actually composed of various genetic polymorphism construction clonial clusters, there existed obvious difference in the clonial distribution and the population genetic construction.Phenotyping analysis for the determination of source of infection and the route of transmission will result in a one-side view.