中央空调冷却塔水嗜肺军团菌PFGE分子分型

目的了解中山市中央空调冷却塔水血清1型(LP1)及血清7型(LP7)嗜肺军团菌脉冲场凝胶电泳(PFGE)分子分型情况。方法对2012—2014年从中山市部分酒店、娱乐场所、商场、医院等公共场所中央空调冷却塔水样本中分离出的41株LP1型嗜肺军团菌和12株LP7型嗜肺军团菌进行脉冲场凝胶电泳,运用Bio Numerics6.6软件进行聚类分析。结果按照100%的相似程度,41株LP1型嗜肺军团菌分为26种PFGE型别,每个带型包括1～6株菌,菌株之间的相似系数为16.6%～100%;12株LP7型嗜肺军团菌分为10种PFGE型别,每个带型包括1～2株菌,菌株之间的相似系数为19.3%～100%。不同地区和不同年份分离的菌株存在相同的PFGE型别;同一场所可存在相同的PFGE型别,也可跨月份或年份存在不同的型别。按照90%以上的相似程度,LP1型嗜肺军团菌有4个克隆群,包含的菌株数和PFGE带型占其血清型别分离株总数以及PFGE型别总数的51.2%(21/41)和30.8%(8/26);LP7型嗜肺军团菌有2个克隆群,包含的菌株数和PFGE带型占其血清型别分离株总数以及PFGE型别总数的50.0%(6/12)和40.0%(4/10)。克隆群在空间和时间分布上无明显差异。结论中山市中央空调冷却塔水中LP1型及LP7型嗜肺军团菌分离株存在广泛的PFGE基因型别,未形成某一优势基因群的地区优势及时间趋势。

PFGE molecular typing of Legionella pneumophila isolated from cooling water of central air-conditioner system

Objective To study the PFGE molecular typing of Legionella pneumophila strains serotype 1 (LP1) and serotype 7 (LP7) isolated from cooling water of central air-conditioner system in Zhongshan. Methods Pulsed-field gel electrophoresis was used to analyze 41 strains of LP1 and 12 strains of LP7 isolated from cooling water of central air-conditioner system in partial public places (hotel, entertainment venue, shopping mall and hospital) of Zhongshan from 2012 to 2014, and the cluster results were analyzed by BioNumerics6.6 software. Results According to 100% similarity, 41 strains of LP1 were divided into 26 PFGE patterns,each pattern contained 1-6 strains with similarity ranged from 16.6%-100%; 12 strains of LP7 were divided into 10 PFGE patterns, each pattern contained 1-2 strains with similarity ranged from 19.3%-100%. Some of Legionella pneumophila strains collected from different districts and different years had same PFGE pattern. Some of Legionella pneumophila strains from same site were identified as same PFGE pattern, while some were identified as different PFGE patterns over months and years. According to over 90% similarity, there were 4 clone groups of LP1, containing number of strains and PFGE patterns accounted for 51.2% （21/41）and 30.8% （8/26）in those of all the serotype 1 strains. There were 2 clone groups of LP7, containing number of strains and PFGE patterns accounted for 50.0% （6/12）and 40.0% （4/10）in those of all the serotype 7 strains. There was no obviously difference among clone groups in spatial distribution and temporal distribution. Conclusion The strains of Legionella pneumophila serotype 1 and 7 isolated from cooling water of central air-conditioner system in Zhongshan were genetic diversity. No dominant clone group was found in spatial trend and temporal trend.