Molecular diversity and high virulence of Legionella pneumophilastrains isolated from biofilms developed within a warm spring of a thermal spa

BMC Microbiology

Research Article

Françoise Forey¹  Monique Reyrolle¹  Sophie Jarraud²  Dominique Fontvieille³  Zineddine Chaabna³  Danièle Atlan⁴  Christophe Gilbert⁴ 

[1] Centre de Biologie et Pathologie Est, Centre National de Référence des Légionelles, F-69677, Bron, France;Centre de Biologie et Pathologie Est, Centre National de Référence des Légionelles, F-69677, Bron, France;Université Lyon, INSERM U851, Université Lyon 1, F-69008, Lyon, France;UMR CARRTEL, Université de Savoie-INRA, F-73376, Le Bourget du Lac, France;Université de Lyon, CNRS UMR 5240, Université Lyon1, F-69622, Villeurbanne, France;

关键词: Legionella pneumophila;    Biofilms;    Warm spring;    Biodiversity;    Virulence;   

DOI  :  10.1186/1471-2180-13-17

 received in 2012-07-24, accepted in 2013-01-14,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundSeveral cases of legionellosis have been diagnosed in the same French thermal spa in 1986, 1994 and 1997. L. pneumophila serogroup 1 (Lp1) strains have been isolated from several patients, but the source of contamination was not identified despite the presence of different Lp1 in water samples of the three natural springs feeding the spa at this period.ResultsOur strategy was to investigate L. pneumophila (Lp) strains from natural biofilms developed in a sulphur-rich warm spring of this contaminated site. Biofilm analysis revealed the presence of three Lp serogroups (Lp1, Lp10 and Lp12). Surprisingly, Lp10 and Lp12 were not reported in the previous described studies from water samples. Besides, the new seven Lp1 we isolated exhibit a high molecular diversity and have been differentiated in five classes according to their DNA genome patterns obtained by PFGE and mip sequences. It must be noted that these DNA patterns are original and unknown in databases. Interestingly, the 27 Lp environmental strains we isolated display a higher cytotoxicity and virulence towards the amoeba Acanthamoeba castellanii than those of known Lp1 epidemic strains.ConclusionThe characteristics of Legionella pneumophila Lp1 strains isolated from the warm spring are in agreement with their presence in biofilms and their probable long-term persistence in this ecosystem.

【 授权许可】

Unknown   
© Chaabna et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.