Analysis of genetic characterization of Legionella isolated in the environment to reduce infection risk

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K16219
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Environmental risk control and evaluation
• Research Institution: Kobe Institute of Health
• Principal Investigator: Nakanishi Noriko 神戸市環境保健研究所, その他部局等, 研究員 (50615490)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: レジオネラ / 遺伝子型別 / 分子疫学 / アメーバ / ゲノム比較解析

Outline of Final Research Achievements

In this study, we aimed to clarify the genetic characteristics and virulence traits of L. pneumophila and the distribution of Legionella spp. isolated from cooling tower (CT) and hot spring (HS). It was elucidated three high clonal groups, CC1, CC2, and CC3, which had colonized cooling towers in Japan over our ten year monitoring period. On the other hand, we found the high prevalence and genetic polymorphism in HS. We also found that L. londiniensis and L. israelensis predominated in HS. Furthermore, core SNPs genotypes were elucidated the genomic proximity and stability between L. pneumophila strains isolated in the same accommodation in HS, despite the difference in separation years. This study highlights the importance of the epidemiology and ecology of Legionella from the standpoint of public health.

Free Research Field

病原微生物学

Academic Significance and Societal Importance of the Research Achievements

レジオネラ症の発生機構を細菌とヒト宿主との関係に着目する病原微生物学だけでなく、生息環境下における病原細菌の挙動に着目する微生物生態学の観点をも有する点に学術的意義がある。また、長期に渡り環境から集積した多種多様なレジオネラ属菌を扱えることから、レジオネラの病原性獲得機構および生存戦略の進化機序を解明でき、レジオネラ症を引き起こす病原性の高い株の選定や環境リスク因子を抽出できる可能性が考えられ、レジオネラ症の予防対策の基盤となる。