Gong Xiangli, Li Juntao, Zhang Ying, Hou Shuiping, Qu Pinghua, Yang Zhicong, Chen Shouyi
Guangzhou Center for Disease Control and Prevention, Guangzhou 510440, China; Ocean University of China, Qingdao 266100, China.
Guangzhou Center for Disease Control and Prevention, Guangzhou 510440, China.
J Microbiol Methods. 2017 Aug;139:1-7. doi: 10.1016/j.mimet.2017.04.002. Epub 2017 Apr 7.
Legionella spp. are important waterborne pathogens. Molecular typing has become an important method for outbreaks investigations and source tracking of Legionnaires. In a survey program conducted by the Guangzhou Center for Disease Control and Prevention, multiple serotypes Legionella pneumophila (L. pneumophila) were isolated from waters in air-conditioning cooling towers in urban Guangzhou region, China between 2008 and 2011. Three genotyping methods, mip (macrophage infectivity potentiator) genotyping, SBT (sequence-based typing), and FAFLP (fluorescent amplified fragment length polymorphism analysis) were used to type these waterborne L. pneumophila isolates. The three methods were capable of typing all the 134 isolates and a reference strain of L. pneumophila (ATCC33153), with discriminatory indices of 0.7034, 0.9218, and 0.9376, for the mip, SBT, and FAFLP methods respectively. Among the 9 serotypes of the 134 isolates, 10, 50, and 34 molecular types were detected by the mip, SBT, and FAFLP methods respectively. The mip genotyping and SBT typing are more feasible for inter-laboratory results sharing and comparison of different types of L. pneumophila. The SBT and FAFLP typing methods were rapid with higher discriminatory abilities. Combinations of two or more of the typing methods enables more accurate typing of Legionella isolates for outbreak investigations and source tracking of Legionnaires.
军团菌属是重要的水源性病原体。分子分型已成为军团菌病暴发调查和源头追踪的重要方法。在广州市疾病预防控制中心开展的一项调查项目中，2008年至2011年期间从中国广州城区空调冷却塔的水中分离出了多种血清型的嗜肺军团菌。采用三种基因分型方法，即巨噬细胞感染增强蛋白（mip）基因分型、基于序列的分型（SBT）和荧光扩增片段长度多态性分析（FAFLP）对这些水源性嗜肺军团菌分离株进行分型。这三种方法能够对所有134株分离株以及一株嗜肺军团菌参考菌株（ATCC33153）进行分型，mip、SBT和FAFLP方法的鉴别指数分别为0.7034、0.9218和0.9376。在134株分离株的9种血清型中，mip、SBT和FAFLP方法分别检测到10种、50种和34种分子型。mip基因分型和SBT分型对于不同类型嗜肺军团菌的实验室间结果共享和比较更可行。SBT和FAFLP分型方法快速且鉴别能力更高。两种或更多种分型方法的组合能够更准确地对军团菌分离株进行分型，用于军团菌病的暴发调查和源头追踪。
