Extensive recombination events and horizontal gene transfer shaped the Legionella pneumophila genomes

BMC Genomics

Research Article

Valerie Barbe¹  Benoit Vacherie¹  Claudine Medigue²  Zoé Rouy²  Laura Gomez-Valero³  Carmen Buchrieser³  Christophe Rusniok³  Jerome Etienne⁴  Sophie Jarraud⁴ 

[1] CEA/DSV/FAR/IG/Genoscope Laboratoire de Génomique Comparative, Evry Cedex, France;CEA/DSV/FAR/IG/Genoscope Laboratoire de Génomique Comparative, Evry Cedex, France;CNRS UMR8030 Laboratoire d'Analyses Bioinformatiques en Métabolisme et Génomique, Evry, France;Institut Pasteur, Biologie des Bactéries Intracellulaires, 75724, Paris, France;CNRS URA 2171, 75724, Paris, France;Lyon, France, Centre National de Référence des Legionella, Université de Lyon, Lyon, France;INSERM, U851, 69007, Lyon, France;Hospices Civils de Lyon, Lyon, France;

关键词: Horizontal Gene Transfer;    Mobile Genetic Element;    Genomic Island;    Cluster Regularly Interspaced Short Palindromic Repeat;    Intragenic Recombination;   

DOI  :  10.1186/1471-2164-12-536

 received in 2011-07-29, accepted in 2011-11-01,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundLegionella pneumophila is an intracellular pathogen of environmental protozoa. When humans inhale contaminated aerosols this bacterium may cause a severe pneumonia called Legionnaires' disease. Despite the abundance of dozens of Legionella species in aquatic reservoirs, the vast majority of human disease is caused by a single serogroup (Sg) of a single species, namely L. pneumophila Sg1. To get further insights into genome dynamics and evolution of Sg1 strains, we sequenced strains Lorraine and HL 0604 1035 (Sg1) and compared them to the available sequences of Sg1 strains Paris, Lens, Corby and Philadelphia, resulting in a comprehensive multigenome analysis.ResultsWe show that L. pneumophila Sg1 has a highly conserved and syntenic core genome that comprises the many eukaryotic like proteins and a conserved repertoire of over 200 Dot/Icm type IV secreted substrates. However, recombination events and horizontal gene transfer are frequent. In particular the analyses of the distribution of nucleotide polymorphisms suggests that large chromosomal fragments of over 200 kbs are exchanged between L. pneumophila strains and contribute to the genome dynamics in the natural population. The many secretion systems present might be implicated in exchange of these fragments by conjugal transfer. Plasmids also play a role in genome diversification and are exchanged among strains and circulate between different Legionella species.ConclusionHorizontal gene transfer among bacteria and from eukaryotes to L. pneumophila as well as recombination between strains allows different clones to evolve into predominant disease clones and others to replace them subsequently within relatively short periods of time.

【 授权许可】

Unknown   
© Gomez-Valero et al; licensee BioMed Central Ltd. 2011. 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.