山东省济南市公共场所集中空调冷却塔水军团菌污染状况调查

Survey on Legionella contamination in water from centralized air conditioning cooling tower in public places in Jinan city,Shandong province

目的了解2013-2022年山东省济南市公共场所集中空调冷却塔水的军团菌污染状况,分析菌株毒力基因携带情况,为军团菌污染防控提供科学数据。方法参照《公共场所集中空调通风系统卫生规范》,2013-2022年对山东省济南市113家公共场所集中空调冷却塔水进行军团菌分离,通过生化培养及飞行时间质谱对疑似菌株进行鉴定。使用诊断血清对嗜肺军团菌进行分型。采用PCR方法扩增菌株的毒力基因lvh和rtxA,产物通过毛细管电泳判读。结果2013-2022年采集山东省济南市113家公共场所集中空调冷却塔水样216份,47份分离到军团菌,检出率为21.8%(47/216)。获得军团菌81株,其中嗜肺军团菌占90.1%(73/81)。73株嗜肺军团菌中,有84.9%(62/73)同时携带lvh和rtxA两种毒力基因,1.1%(8/73)仅携带一种毒力基因。其余3株嗜肺军团菌及8株非嗜肺军团菌均未检出lvh和rtxA。结论济南市公共场所集中空调冷却塔水军团菌污染较为严重,存在公共卫生危害。分离的嗜肺军团菌大多数均携带lvh和rtxA两种毒力基因,可能导致军团菌病。

Objective To understand the contamination status of Legionella in water from centralized air conditioning cooling tower in public places from 2013 to 2022 in Jinan city,Shandong province,and analyze the virulence genes of the strains,so as to provide scientific data for Legionella contamination control and prevention.Methods From 2013 to 2022,according to the Hygienic Standards for Centralized Air Conditioning and Ventilation Systems in Public Places,Legionella were isolated in the water from 113 centralized air conditioning cooling towers in Jinan city.The suspected strains were identified through biochemical culture and time-of-flight mass spctrometry.Legionella pneumophila was classified by diagnostic serum.The virulence genes lvh and rtxA were amplified by PCR,and the products were identified by capillary electrophoresis.Results From 2013 to 2022,a total of 216 water samples were collected from 113 centralized air conditioning cooling tower in public places in Jinan city,Shandong province,and Legionella were detected from 47 samples,with a positive rate of 21.8%.A total of 81 Legionella were isolated and 90.1%(73/81)of them were Legionella pneumophila.Among these 73 Legionella pneumophila,84.9%(62/73)carried 2 virulence genes(lvh and rtxA),while 1.1%(8/73)only carried 1.lvh or rtxA was not detected in the other three Legionella pneumophila and eight Legionella non-pneumophila strains.Conclusion Legionella contamination in the water from centralized air conditioning cooling towers in public places in Jinan city is relatively serious with public health risks.Most of the isolated Legionella pneumophila carried 2 virulence genes,lvh and rtxA,which may lead to Legionella disease.