嗜肺军团菌基因检测及分子特征研究

Study on gene detection and molecular characteristics of Legionella pneumophila

目的:了解外环境水中分离的嗜肺军团菌菌株的基因特征及遗传背景。方法:40株分离株分别经血清学凝集试验、胶乳凝集试验确定为LP1型嗜肺军团菌后,利用普通PCR技术对军团菌属5S rRNA基因和嗜肺军团菌mip毒力基因的特异序列进行扩增,应用实时荧光定量PCR技术扩增嗜肺军团菌mip基因,使用脉冲场凝胶电泳(PFGE)分型技术对菌株进行全染色体DNA酶切电泳分型,并用BioNumerics Version 4.0软件进行聚类分析。结果:所有的菌株均带有属特异性5S rRNA基因及mip毒力基因,PFGE聚类分析结果显示大多数菌株的遗传相似度有一定差异。结论:所有菌株经普通PCR或定量PCR均相应扩增出其特征基因,PFGE聚类分析结果提示浙江省散在水系中分离的嗜肺军团菌菌株存在遗传多样性。

Objective：To investigate the genetic characteristics and heredity background of LP1 Legionella strains isolated from environmental water. Methods： Forty isolates were confirmed to be LP1 Legionella by serological and latex agglutination. Polymerase chain reaction （PCR） was used for 5S rRNA genc and mip toxic gene detection. Furthermore, fluorescence quantitative PCR （FQ - PCR） was used for mip gene detection. Pulse field gel electronphoresis （PFGE） was applied for chromosomal gene typing, and BioNumerics software was applied for cluster analysis. Results：All of the strains carried both 5S rRNA gene and mip toxic gene. The cluster analysis results of PFGE maps showed that most of the strains differed in genetic similarity. Conclusion ： Characterized genes are detected positive in all of the strains with PCR and FQ - PCR. According to the cluster analysis results of PFGE maps ,genetic diversity exists in LP1 Legionella strains isolated from environmental water in Zhejiang Province.