2012—2018年中山市集中空调冷却塔水嗜肺军团菌分子分型及分布特征

Molecular typing and distribution characteristics of Legionella pneumophila isolated from cooling water of central air conditioning system in Zhongshan,2012-2018

目的分析中山市2012—2018年公共场所集中空调冷却塔水嗜肺军团菌分离株的基因特征,了解同源菌株时空分布特征,为嗜肺军团菌的防控和溯源提供依据。方法将分离获得的85株嗜肺军团菌进行血清型鉴定,采用脉冲场凝胶电泳(PFGE)对85株嗜肺军团菌进行分子分型。利用GIS地理编码技术对菌株来源地址进行经纬度转换,应用Qgis 2.18.11空间处理软件将地址叠加到中山市地图上,制作聚类簇分子分型空间分布特征地图。结果85株嗜肺军团菌包括9种血清型,以LP1占比最高为61.18%(52/85)。按照100%的相似程度,85株嗜肺军团菌经聚类分析可得到56种PFGE带型(T1-T56),3种优势型别。同一血清型菌株的PFGE型别较为多样;不同血清型的菌株基本存在不同的PFGE型别,也有存在相同的PFGE型别。按照85%以上相似性系数得到8个聚类簇(A-H),分布在12个地区。PFGE聚类簇不存在明显的时间和地区分布差异,也不存在时间和地区聚集性分布。结论中山市2012—2018年公共场所集中空调冷却塔水嗜肺军团菌分离株血清型以LP1为主,菌株分子分型呈现多样性,聚类簇分离株不存在不同年份和地区的分化克隆群。

Objective To analyze the genetic characteristics of Legionella pneumophila isolated from cooling water of central air conditioning system in public places in Zhongshan from 2012 to 2018,and to understand the spatiotemporal distribution of homologous strains,in order to provide evidence for the prevention,control and traceability of Legionella pneumophila infection.Methods Eighty-five Legionella pneumophila strains were isolated for serotype identification,and the molecular typing of the 85 isolates was performed using pulsed field gel electrophoresis(PFGE).The strain location data was converted into latitude and longitude coordinates by GIS geocoding technology.The converted location data was overlaid on the map of Zhongshan City,mapping the molecular typing distribution of clusters using Qgis2.18.11 spatial processing software.Results Eighty-five strains of Legionella pneumophila included 9 serotypes,and the highest proportion was LP1,accounting for 61.18%(52/85).According to the similarity of 100%,85 strains of Legionella pneumophila were divided into 56 patterns of PFGE bands(T1-T56),with 3 types being dominant.Same serotype of Legionella pneumophila strains showed diverse PFGE patterns.Different serotypes of Legionella pneumophila strains were basically identified as different PFGE patterns,while some were identified as same PFGE pattern.According to over 85%similarity,8 clusters(A-H)were designated,strains of which were distributed in 12 districts.PFGE clustering clusters did not display obvious temporal and regional distribution differences,nor did they have temporal and regional clustering distributions.Conclusion Strains of Legionella pneumophila isolated from cooling water of central air conditioning system in public places in Zhongshan from 2012 to 2018 showed genetic diversity,and the main serotype was LP1.Isolates of clusters did not exist in different years or regions.