一类罕见硫化氢阴性山夫登堡沙门菌腹泻株的分子溯源

Molecular tracing of infection source of rare H_2S negative strains of Salmonella Senftenberg

[目的]研究一类罕见硫化氢阴性山夫登堡沙门菌腹泻菌株遗传克隆特征。[方法]收集、分析本地区参加全球沙门菌监测(GSS)腹泻病例中分离的山夫登堡沙门菌生化、编码SPI-1毒力岛基因(hilA、invA)和耐药特征;应用Riboprinter(r)(RP)DNA指纹图谱系统比较表型典型与不典型菌株的核糖体分型;通过Pluse Net China数据库中同型菌株的脉冲凝胶电泳(PFGE)图谱聚类比较分子型谱。[结果]2006年长宁区GSS监测病例分离出19株山夫登堡沙门菌,其中10株属于硫化氢阴性和SPI-1毒力岛缺失的表型变异菌株。RP分型证实发生变异的山夫登堡沙门菌与典型菌株间分属2个不同的克隆。Pluse Net China数据库将包括长宁区19株山夫登堡沙门菌在内的36株山夫登堡腹泻株共分18种PFGE带型。长宁区的表型变异株优势型分属4型(2株)和6型(6株),典型菌株的优势型分属11型(1株)、17型(4株)和23型(2株)。聚类分析显示,表型变异株的克隆在遗传相似度上高于典型株。[结论]分子溯源证实,SPI-1毒力岛缺失的山夫登堡沙门菌变异菌株与典型菌株同样具有引发局部爆发的致病性。2006年长宁区分离的硫化氢阴性山夫登堡沙门菌变种腹泻株与2002年深圳市的1例食物中毒案例分离的2株SPI-1毒力岛缺失株存在同源性。

[ Objective ] To investigate the genetic clone characteristics of rare H2S negative strains of Salmonella enterica subsp, enterica serovar Senftenberg（S. Senftenberg） . [ Methods ] A retrospective analysis was performed to explore the characteristics of biochemical test, encoding Salmonella pathogenecity island gene 1 （ SPI - 1 ） and antibiotic resistance of S. Senfienberg from diarrhea patients in Shanghai Global Salm - Surv （ GSS ）. Ribotyping comparisons were made between typical and atypical strains of S. Senftenberg using Riboprinter, （RP） DNA finger printing technique. Using cluster analysis we compared the molecular subtyping of these strains with the same serotyping strains in China PulseNet dynamic database by PFGE. [ Results] Of 19 strains of S. Senftenberg isolated from Changning district GSS - Surv hospital, there were 10 phenotype variant strains found to be H2S negative and lacking SPI - 1. There were two different clones between variant strains and typical strains, which was proved by RP Ribotyp- ing. Thirty six strains of S. Senftenberg including 19 strains from Changning district were divided into 18 PFGE typing - pattens by China PulseNet database. The PFGE subtype 4 （ 2 strains ） and 6 （ 6 strains ） were the predominant epidemic strains of variant strains , the subtype 11 （ 1 strains ） , 17 （4 strains ） and 23 （ 2 strains ） were the predominant epidemic strains of typical strains in Changning district. Cluster analysis showed the clone of variant strains was higher than that of the typical riant strains of S. Senti strains in genetic similarity. [ Conclusion ] The molecular tracing of source confirms that vaenberg lacking SPI - 1 can induce sporadic outbreak as the typical strains. There was homologous nature between H2S negative variant strains of S. Senftenberg isolated from diarrhea patients in 2006 in Changning district and two strains of S. Senftenberg lacking SPI - 1 from a food - borne disease outbreak in 2002 in Shenzhen.