榆林市2017-2020年公共场所空调冷却塔水嗜肺军团菌的调查研究  

Investigation of Legionella pneumophila in the water of air condition cooling towers of public places in Yulin from 2017 to 2020

作　　者：钟瑞 王彩乔 钟笑 王治平[1] 焦亚东[1] ZHONG Rui;WANG Cai-qiao;ZHONG Xiao;WANG Zhi-ping;JIAO Ya-dong(Yulin City Center for Disease Control and Prevention,Shaanxi 719000,China)

机构地区：[1]榆林市疾病预防控制中心,陕西719000

出　　处：《医学动物防制》2022年第7期659-662,共4页Journal of Medical Pest Control

基　　金：榆林市食品安全和卫生应急市级重点实验室建设项目(榆政财教发[2018]152号)。

摘　　要：目的了解2017—2020年榆林市公共场所集中空调系统冷却塔水嗜肺军团菌(Legionella pneumophila,Lp)的污染情况,为嗜肺军团菌防控提供数据支撑。方法采用分离培养法进行嗜肺军团菌分离、鉴定和血清分型。荧光定量PCR检测所有样品的mip基因,检出率和分离培养法分离率做卡方检验。对部分菌株进行16S rRNA基因测序,将所得序列在GenBank中Blast比对,并用DNA Star和Mega 5进行同源性和系统发育分析。结果138份样品中分离到嗜肺军团菌38株,分离率27.54%。嗜肺军团菌血清型存在多样性,包括Lp1、Lp4、Lp6、Lp7、Lp8、Lp9型,其中Lp1型17株,占44.74%,为优势血清型。PCR检出率明显高于分离培养法,为47.10%,差异有统计学意义(χ^(2)=11.29,P<0.05)。16S基因在NCBI上经Blast比对,显示本研究序列和嗜肺军团菌的GC-B2、ERS1305867同源性最高(99.8%~100.0%)。系统发育树显示16S rRNA基因序列分析与血清学分析差异明显,但本研究的两条Lp1序列聚拢在一起。结论榆林市公共场所中央空调冷却塔水嗜肺军团菌污染较严重,很可能引起军团病的暴发。应引起相关部门的重视,监督企业加强空调系统的清洗和消毒,同时做好外环境的监测,预防军团病的发生。Objective To provide data support for Legionella pneumophila(Lp)prevention and control by understanding the contaminations of Lp in air condition cooling towers at public places in Yulin from 2017 to 2020.Methods The isolation,identification and serotype of Lp from samples were conducted by means of the isolation culture method.Fluorogenic quantitative PCR was used to detect the mip genes in the samples,Chi-square test was performed for the detection rate and the isolation rates of isolated culture method.Some strains were subject to 16 S rRNA gene sequencing,the obtained sequences were Blast aligned in GenBank,then the homologous and phylogenetic analysis were performed using DNA Star and Mega 5.Results Totally 38 Lp strains out of 138 samples with an isolation rate of 27.54%were isolated.The serotypes of Lp were diverse,including Lp1,Lp4,Lp6,Lp7,Lp8 and Lp9,among them,17 strains of Lp1 were the superiority serotype,accounting for 44.74%.The detection rate of PCR was significantly higher than that of isolation culture method(47.10%),and the difference was statistically significant(χ^(2)=11.29,P<0.05).Blast comparison of 16 S genes based on NCBI showed that the sequence of the present study was found to have the maxium homology with GC-B2 and ERS1305867(99.8%-100.0%).Phylogenetic tree showed the difference between 16 S rRNA gene analysis and serological analysis was significant.While two Lp1 sequences in this study were gathered together.Conclusion The contamination of Lp in the air condition cooling towers of public places in Yulin is serious,and it may cause the outbreak of legionnaires′disease.The competent authorities should throw concerns,supervise the cleaning and disinfection of air condition cooling towers,and properly conduct the surveillance on external environment to prevent the infection of legionnaires′disease.

关 键 词：冷却塔水 嗜肺军团菌 分离培养 同源性 系统发育分析 16S rRNA基因 

分 类 号：R126.4[医药卫生—环境卫生学] R378[医药卫生—公共卫生与预防医学]