Department of Parasitology, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu 610041, Sichuan, China; Sichuan Center for Disease Control and Prevention, Chengdu 610041, Sichuan, China.
Sichuan Center for Disease Control and Prevention, Chengdu 610041, Sichuan, China.
Biomed Environ Sci. 2019 Jul;32(7):520-530. doi: 10.3967/bes2019.069.
To investigate the molecular characteristics and intracellular growth ability of Legionella pneumophila (L. pneumophila) strains from 1989 to 2016 in Sichuan Province, China.
Seventy-nine isolates of L. pneumophila were collected from environmental and clinical sources, including cooling towers, hot springs, bath water, fountains, and patients, and identified with 16S rRNA gene analysis and serum agglutination assay. The isolates were then typed by Sequence-Based Typing (SBT), and Genotyping of forty-two LP1 strains were analyzed by means of multiple-locus VNTR analysis with 8 loci (MLVA-8). All strains were further analyzed for two virulence genes: Legionella vir homologue (lvh) and repeats in structural toxin (rtxA). The intracellular growth ability of 33 selected isolates was determined by examining their interaction with J774 cells.
All isolates were identified to L. pneumophila including 11 serogroups, among which the main serogroup were LP1, accounting for 54.43%. Thirty-three different sequence types (STs) from five main clonal groups and five singletons were identified, along with 8 different MLVA patterns. Both the lvh and rtxA loci were found in all 79 strains. Thirty isolates showed high intracellular growth ability in J774 cells.
L. pneumophila is a potential threat to public health, and effective control and prevention strategies are urgently needed.
调查 1989 年至 2016 年期间中国四川省嗜肺军团菌（L. pneumophila）菌株的分子特征和细胞内生长能力。
从冷却塔、温泉、洗浴水、喷泉和患者等环境和临床来源中收集了 79 株嗜肺军团菌分离株，通过 16S rRNA 基因分析和血清凝集试验进行鉴定。然后通过序列分型（SBT）对分离株进行分型，并用 8 个基因座（MLVA-8）的多位点 VNTR 分析对 42 株 LP1 株进行基因分型。所有菌株进一步分析了两个毒力基因：军团菌同源物（lvh）和结构毒素重复序列（rtxA）。通过检测与 J774 细胞的相互作用，确定 33 株选定分离株的细胞内生长能力。
所有分离株均鉴定为嗜肺军团菌，包括 11 个血清群，其中主要血清群为 LP1，占 54.43%。从五个主要克隆群和五个单克隆群中鉴定出 33 个不同的序列型（ST），以及 8 种不同的 MLVA 模式。79 株菌均存在 lvh 和 rtxA 基因座。30 株在 J774 细胞中表现出高细胞内生长能力。
嗜肺军团菌对公共健康构成潜在威胁，迫切需要采取有效的控制和预防策略。
