Analysis of Genetic Characterization and Clonality of Legionella pneumophila Isolated from Cooling Towers in Japan
Analysis of Genetic Characterization and Clonality of Legionella pneumophila Isolated from Cooling Towers in Japan
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DOI：
10.3390/ijerph16091664
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发表时间：
2019-05
影响因子：
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通讯作者：
N. Nakanishi;R. Nomoto;Shinobu Tanaka;K. Arikawa;T. Iwamoto
中科院分区：
文献类型：
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作者：
N. Nakanishi;R. Nomoto;Shinobu Tanaka;K. Arikawa;T. Iwamoto
我们调查了 10 年来从日本冷却塔中分离出的 161 株嗜肺军团菌的遗传特征。基于序列分型（SBT）的最小生成树分析确定了三个克隆复合体（CC）； CC1 (105/161, 65.2%)、CC2 (22 /161, 13.7%) 和 CC3 (20/161, 12.4%)。 CC1由血清群(SG)1和SG7形成，而CC2主要由SG1形成。除两个菌株外，所有 CC3 分离株均为 SG13。 CC1 和 CC2 中的主要序列类型 (ST) 分别是 ST1 (88/105, 83.8%) 和 ST154 (15/22, 68.2%)。这些 ST 被认为是日本冷却塔中嗜肺军团菌 SG1 的典型类型。此外，我们还鉴定出 15 个 ST2603 菌株作为 CC3 中的主要类型。该ST在日本冷却塔中尚未见报道。对 10 年来从各个冷却塔中分离出的三个 CC 中的代表性菌株进行全基因组测序 (WGS) 分析，阐明了日本冷却塔中嗜肺军团菌的高克隆种群。此外，CC2菌株与CC1和CC3菌株相比，在系统发育上较远，属于嗜肺军团菌亚种（L. pneumophila subsp.）。弗拉塞里。
We investigated the genetic characteristics of 161 Legionella pneumophila strains isolated over a period of 10 years from cooling towers in Japan. Minimum spanning tree analysis based on the sequence-based typing (SBT) of them identified three clonal complexes (CCs); CC1 (105/161, 65.2%), CC2 (22 /161, 13.7%), and CC3 (20/161, 12.4%). CC1 was formed by serogroup (SG) 1 and SG7, whereas CC2 was mainly formed by SG1. All of the CC3 isolates except two strains were SG13. The major sequence types (STs) in CC1 and CC2 were ST1 (88/105, 83.8%) and ST154 (15/22, 68.2%), respectively. These STs are known as typical types of L. pneumophila SG1 in Japanese cooling tower. Additionally, we identified 15 strains of ST2603 as the major type in CC3. This ST has not been reported in Japanese cooling tower. Whole genome sequencing (WGS) analysis of the representative strains in the three CCs, which were isolated from various cooling towers over the 10 years, elucidated high clonal population of L. pneumophila in Japanese cooling tower. Moreover, it revealed that the strains of CC2 are phylogenetically distant compared to those of CC1 and CC3, and belonged to L. pneumophila subsp. fraseri.