贵州省伤寒沙门菌分离株16s核糖体基因型的多态性及其流行病学意义

Diversity of 16s rDNA ribotypes of the Salmonella typhi strains isolated in Guizhou province

目的 探讨贵州省不同时间、不同地区伤寒流行菌株的遗传多态性及内在联系。方法 利用southern杂交技术 ,对贵州省 9个地区 2 6个县、市 195 9～ 1999年伤寒沙门菌分离株进行染色体DNA基因限制性酶切 16srDNA探针杂交图谱分析及药物敏感性试验。结果 分析发现选择的2 0 9株分属 2 6个RT型 ,以RT1和RT2为优势型 ;在局部发生伤寒流行时 ,均由独特RT型引起。耐药菌株以RT7和RT1型为主。结论 贵州省不同地区、不同时间的分离菌株在核糖体杂交图谱上有明显的多态性 ,分析认为具有多重耐药性以及存在众多克隆群菌株是引起贵州伤寒发病率居高不下的主要原因。

Objective To analyses the genetic diversity and relationship of Salmonella typhi strains isolated from different years and districts in Guizhou province. Methods Ribotyping with 16s rDNA probe was used to describe the diversity of the 209 strains which were isolated in 26 counties of Guizhou province, from 1959 to 1999. The antibiotics resistance was also studied. Results Twenty-six ribotypes were found in all 209 strains, with two dominant types. The strains isolated from local typhoid epidemics belonged to the unique Ribotypes. The major ribotypes of the resistant strains were RT7 and RT1. Conclusion The Salmonella typhi isolates from Guizhou diverged obviously. The abundant clones and multi-resistance of the strains might serve the major reasons of the high morbidity of typhoid in Guizhou.