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目的了解浙江省空调冷却塔/冷凝水中嗜肺军团菌血清1型(Lp1)菌株的序列分型特征。方法选取2005～2011年间浙江省10个地区空调冷却塔/冷凝水中分离的61株Lp1型嗜肺军团菌菌株,采用欧盟军团菌感染工作组(EWGLI)军团菌序列分型(SBT)方法,PCR扩增7对管家基因,对扩增产物进行测序、比对、递交,以获取等位基因号以及SBT序列型,运用DNAsp 5.0软件对测序结果进行核苷酸多态性分析,采用SplitsTree及eBURST软件对分型结果进行聚类分析。结果 61株Lp1型嗜肺军团菌可分为11种SBT序列型,其中5株(5/61)均为新发现序列型;ST-1型在10个地区(市)的冷却塔/冷凝水中均有分布,该序列型菌株占81.9%(50/61)。7个管家基因的核苷酸多态性(Pi)范围为0.01095(mip)～0.05355(pilE)。聚类分析显示,浙江省Lp1型菌株分属多个克隆系,但主要分属ST-1序列群、ST-154序列群和ST-149三大序列群,另有1株为不属于任何序列群的单体。结论聚类分析表明浙江省空调冷却塔/冷凝水中分离的Lp1型嗜肺军团菌存在遗传多样性,序列群分布与国内部分省份的结果相似,以ST-1序列型为主。
Objective To understand the sequence typing characteristics of Legionella pneumophila serotype 1 (Lp1) strains in air conditioning cooling tower / condensate water in Zhejiang Province. Methods Totally 61 strains of Legionella pneumophila Lp1 isolated from air-conditioning cooling tower / condensate water in 10 districts of Zhejiang Province from 2005 to 2011 were selected. Legionella pneumophila serogroups (EWGLI) Seven pairs of housekeeping genes were amplified, and the amplified products were sequenced, aligned and submitted to obtain the allele number and SBT sequence type. Nucleotide polymorphisms were analyzed using DNAsp 5.0 software. SplitsTree and eBURST The software performs clustering analysis on the classification results. Results 61 strains of Legionella pneumophila Lp1 were classified into 11 SBT sequences, of which 5 (5/61) were newly discovered. ST-1 was found in 10 cooling tower / condensate water in 10 cities All the strains were sequenced, accounting for 81.9% (50/61). Nucleotide polymorphisms (Pi) of 7 housekeeping genes ranged from 0.01095 (mip) to 0.05355 (pilE). Cluster analysis showed that Lp1 strains belong to several clonal lines in Zhejiang Province, but mainly belong to ST-1 sequence group, ST-154 sequence group and ST-149 three sequence groups, and another strain belongs to any sequence Single group. Conclusion The cluster analysis showed that the genetic diversity of Legionella pneumophila Lp1 isolated from the air-conditioning cooling tower / condensate water in Zhejiang Province was similar. The distribution of the sequence group was similar to the results of some provinces in China, and the predominant ST-1 sequence type.