title: Recombination drives genome evolution in outbreak-related Legionella pneumophila isolates.
abstract: Legionella pneumophila is a strictly environmental pathogen and the etiological agent of legionellosis. It is known that non-vertical processes have a major role in the short-term evolution of pathogens, but little is known about the relevance of these and other processes in environmental bacteria. We report the whole-genome sequencing of 69 L. pneumophila strains linked to recurrent outbreaks in a single location (Alcoy, Spain) over 11 years. We found some examples where the genome sequences of isolates of the same sequence type and outbreak did not cluster together and were more closely related to sequences from different outbreaks. Our analyses identify 16 recombination events responsible for almost 98% of the SNPs detected in the core genome and an apparent acceleration in the evolutionary rate. These results have profound implications for the understanding of microbial populations and for public health interventions in Legionella outbreak investigations.
authors.affiliation: 1] Infection and Public Health Joint Unit, FISABIO (Fundación para el Fomento de la Investigación Biomédica y Sanitaria de la Comunidad Valenciana), University of Valencia-Cavanilles Institute for Biodiversity and Evolutionary Biology, Valencia, Spain. [2] CIBER (Centro de Investigación Biomédica en Red) in Epidemiology and Public Health, Valencia, Spain.
authors.forename: Leonor
authors.initials: L
authors.lastname: Sánchez-Busó
authors.affiliation: 1] Infection and Public Health Joint Unit, FISABIO (Fundación para el Fomento de la Investigación Biomédica y Sanitaria de la Comunidad Valenciana), University of Valencia-Cavanilles Institute for Biodiversity and Evolutionary Biology, Valencia, Spain. [2] CIBER (Centro de Investigación Biomédica en Red) in Epidemiology and Public Health, Valencia, Spain.
authors.forename: Iñaki
authors.initials: I
authors.lastname: Comas
authors.affiliation: Public Health Centre, Alcoy, Spain.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Jorques
authors.affiliation: 1] Infection and Public Health Joint Unit, FISABIO (Fundación para el Fomento de la Investigación Biomédica y Sanitaria de la Comunidad Valenciana), University of Valencia-Cavanilles Institute for Biodiversity and Evolutionary Biology, Valencia, Spain. [2] CIBER (Centro de Investigación Biomédica en Red) in Epidemiology and Public Health, Valencia, Spain.
authors.forename: Fernando
authors.identifier: 0000000208795798
authors.initials: F
authors.lastname: González-Candelas
mesh_terms: D001483:Base Sequence; D001499:Bayes Theorem; D004196:Disease Outbreaks; D019143:Evolution, Molecular; D016680:Genome, Bacterial / Q000235:genetics*; D023281:Genomics / Q000379:methods; D006801:Humans; D016952:Legionella pneumophila / Q000235:genetics*; D007877:Legionnaires' Disease / Q000453:epidemiology* / Q000235:genetics; D016013:Likelihood Functions; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011995:Recombination, Genetic / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013030:Spain / Q000453:epidemiology