一株水源分离军团菌的分子生物学鉴定和系统发育学及毒力分析  

Molecular Identification,Phylogenic and Virulence Analysis of a Legionella Strain Isolated from Aquatic Environment

作　　者：关望[1] 陈建平[1] 徐佳楠[1] 许颖[1] 

机构地区：[1]四川大学华西基础医学与法医学院寄生虫学教研室.病原生物学研究室,成都610041

出　　处：《四川大学学报（医学版）》2012年第1期50-53,59,共5页Journal of Sichuan University(Medical Sciences)

基　　金：国家自然科学基金(批准号81001345;30771883);教育部博士学科点专项科研基金(20060610091)资助

摘　　要：目的对我室2009年分离获得的一株疑似军团菌菌株(编号为CD-1)进行分子生物学鉴定、系统发育学及毒力分析。方法对CD-1株进行PCR扩增军团菌属特异性16SrRNA作为分子生物学鉴定,扩增其rpoB基因片段并测序进行系统发育学分析。对CD-1株进行PCR扩增以检测其毒力基因mip,并用CD-1株感染BABL/c小鼠以研究其毒力。结果 PCR扩增军团菌属特异性16SrRNA显示CD-1株在650bp处有特异条带,说明CD-1株为一株军团菌,系统发育学分析显示CD-1株与长滩军团菌(Legionella longbeachae)聚为一枝,其后验概率为1.00。对CD-1株进行军团菌毒力基因mip扩增,扩增产物在650bp处有特异条带,显示CD-1株携带有mip基因。动物实验结果显示当感染菌量浓度达到107 cfu/mL时,实验组小鼠全部死亡。结论 CD-1株为一株长滩军团菌,对BALB/c小鼠具有较强毒力,并且有可能对人体致病。这是四川地区分离获得的首株长滩军团菌,也是国内首次对水源分离军团菌毒力进行报道。Objective CD-1 was isolated from aquatic environment,which grew with strict L-cysteine dependence.In this study,we applied molecular methods to identify CD-1,and animal test to understand its virulence. Methods To identify CD-1 strain,CD-1 strain was tested for genus-specific 16S rRNA of Legionella via PCR amplification,then its rpoB gene was sequenced for phylogenic analysis.To understand the virulence,CD-1 was detected for mip gene,which was an indispensable virulent gene of Legionella.Then,BABL/c mice were infected by CD-1 in different dosages.Results For identification,CD-1 was positive for genus-specific 16S rRNA of Legionella,while in the phylogenic tree CD-1 was a sister to Legionella longbeachae with high posterior probability（PP=1.00）.For the virulence analysis,CD-1 was positive for mip gene detection.In the animal test,all mice tested died when the infection dose of CD-1 strain reached 107 cfu/mL.Conclusion CD-1 strain was identified to be Legionella longbeachae with strong virulence to BALB/c mice.It may be a potential virulent strain to human.This is the first strain of Legionella longbeachae isolated in Sichuan province,and this is the first virulence analysis of Legionella strain isolated from aquatic environment in China.

关 键 词：军团菌 水环境 系统发育学 毒力 

分 类 号：R378[医药卫生—病原生物学]