温泉水中嗜肺军团菌污染调查及分子分型研究

目的 探讨温泉水环境中嗜肺军团菌的污染状况和分布规律,了解其主要血清型别及基因型别。方法 采取随机抽样方法采集温泉场所蓄水池、温泉池、客房淋浴水等,浓缩后用细菌培养法分离得到可疑菌株,用血清学与荧光定量 PCR技术进行嗜肺军团菌的鉴定。对分离的菌株用脉冲场凝胶电泳(PFGE)和多位点序列分型方法(SBT)进行基因分型。结果 65份温泉水中35份检出嗜肺军团菌,检出率为53.85%。嗜肺军团菌计数范围在20 CFU/100 mL-16 000 CFU/100 mL之间。血清分型以LP1、LP3为主。分离的嗜肺军团菌菌株均携带dot基因。对40株嗜肺军团菌菌株进行了PFGE聚类分析,得到10种不同的带型。40株菌株13种ST型可以被分为3个克隆群和1个单态群。结论 本地区温泉水嗜肺军团菌污染程度较高,分子分型结果表明这些菌株具有遗传多样性。

Contamination status and molecular typing of Legionella pneumophila in spring environments

To research the contamination status and distributive regulation of Legionella pneumophila in samples from spring water and analyze the main serotypes and genotypes of the pathogen, a stratified sampling method was adopted to collect water samples randomly from water tank, hot spring pool, shower room of hot spring recreations. Suspected strains were isolated from condensed water samples. Serum agglutination assay and real-time PCR technology were used to identify L. pneumophila. Pulsed-field gel electrophoresis (PFGE) and sequence-based typing (SBT) were used to describe the genetic polymorphism of the isolates. Overall, 53.85% of water samples showed Legionella-positive, and their concentrations ranged from 20 CFU/100 mL to 16 000 CFU/100 mL. The main serotypes were LP1 type and LP3 type and all strains carried dot gene. Among them, 40 isolates were analyzed by PFGE by which 10 distinct patterns were differentiated. They were also selected for SBT analysis and divided into 13 different sequence types in 3 main clonal groups belonging to one homomorphic type. Our results demonstrated high prevalence and genetic polymorphism of Legionella in hot spring recreations of Wenzhou. Hot spring area posed a potential threat to tourists. Spring water of these places should be intervened to prevent occurrence of Legionnaires? disease.