论文部分内容阅读
目的对中国不同自然环境来源分离的嗜肺军团菌血清1型菌株进行分子分型和种群结构分析。方法应用7个基因(fla A、pil E、asd、mip、momp S、pro A、neu A)序列分型方法(Sequence based typing,SBT)对不同环境来源的206株嗜肺军团菌血清1型菌株进行分型研究,通过查询嗜肺军团菌SBT数据库(http://www.ewgli.org)和用Bio Numerics软件构建最小生成树揭示菌株的分子分型和种群结构特征。结果 206株菌分成54个ST型(IOD=0.7205)。其中49株温泉水分离株分成25个ST型(IOD=0.9498),各位点Nei指数0.7721~0.8563;130株冷却塔水分离株分成31个ST型(IOD=0.6453),各位点Nei指数为0.4227~0.4970;27株管道水分离株分成3个ST型(IOD=0.1453),各位点Nei指数为0.1425~0.1453。ST1型含108株菌,占52.4%,是优势带型。54个ST型形成5个克隆群。通过中国菌株和其他20个国家的菌株综合分析,共计1199株菌分成304个ST型,形成21个序列群。其中ST-1型为全球优势型别,其余型别和序列群呈地区性分布特征。结论中国环境分离的嗜肺军团菌1型菌株具有高度复杂的基因多态性和种群结构,其中ST1是我国也是全球环境菌株的优势型别。
Objective To analyze the molecular typing and population structure of Legionella pneumophila serotype 1 isolates from different natural environments in China. Methods Sixty-two Legionella pneumophila serotype 1 strains from different environments were sequenced using sequence-based typing (flaA, pil E, asD, mip, momp S, pro A, neu A) Strains were genotyped and the molecular typing and population structure characteristics of the strains were revealed by interrogating the Legionella pneumophila SBT database (http://www.ewgli.org) and constructing the minimal spanning tree with Bio Numerics software. Results 206 strains were divided into 54 ST type (IOD = 0.7205). Among them, 49 strains of hot spring water were divided into 25 ST types (IOD = 0.9498) and Nei index (0.7721-0.8563) at each locus. Water pools of 130 cooling towers were divided into 31 ST types (IOD = 0.6453), Nei index of each locus was 0.4227 ~ 0.4970. The 27 strains of water pipelines were divided into three ST types (IOD = 0.1453) and the Nei index of each locus was 0.1425 ~ 0.1453. ST1 contains 108 strains of bacteria, accounting for 52.4%, is the dominant band. 54 ST types formed 5 clonal groups. A total of 1199 strains were divided into 304 ST types through the comprehensive analysis of strains from China and other 20 countries, forming 21 sequence groups. Among them, ST-1 type is the dominant type in the world, and the rest types and sequence groups are characterized by regional distribution. Conclusion Legionella pneumophila type 1 isolates from China have highly complex genetic polymorphisms and population structure. Among them, ST1 is the predominant type in China and the global environmental strains.