title: Genomic evidence for the emergence and evolution of pathogenicity and niche preferences in the genus Campylobacter.
abstract: The genus Campylobacter includes some of the most relevant pathogens for human and animal health; the continuous effort in their characterization has also revealed new species putatively involved in different kind of infections. Nowadays, the available genomic data for the genus comprise a wide variety of species with different pathogenic potential and niche preferences. In this work, we contribute to enlarge this available information presenting the first genome for the species Campylobacter sputorum bv. sputorum and use this and the already sequenced organisms to analyze the emergence and evolution of pathogenicity and niche preferences among Campylobacter species. We found that campylobacters can be unequivocally distinguished in established and putative pathogens depending on their repertory of virulence genes, which have been horizontally acquired from other bacteria because the nonpathogenic Campylobacter ancestor emerged, and posteriorly interchanged between some members of the genus. Additionally, we demonstrated the role of both horizontal gene transfers and diversifying evolution in niche preferences, being able to distinguish genetic features associated to the tropism for oral, genital, and gastrointestinal tissues. In particular, we highlight the role of nonsynonymous evolution of disulphide bond proteins, the invasion antigen B (CiaB), and other secreted proteins in the determination of niche preferences. Our results arise from assessing the previously unmet goal of considering the whole available Campylobacter diversity for genome comparisons, unveiling notorious genetic features that could explain particular phenotypes and set the basis for future research in Campylobacter biology.
authors.affiliation: Unidad de Bioinformática, Institut Pasteur Montevideo, Montevideo, Uruguay Sección Genética Evolutiva, Facultad de Ciencias, Montevideo, Uruguay giraola@pasteur.edu.uy.
authors.forename: Gregorio
authors.initials: G
authors.lastname: Iraola
authors.affiliation: Sección Genética Evolutiva, Facultad de Ciencias, Montevideo, Uruguay.
authors.forename: Ruben
authors.initials: R
authors.lastname: Pérez
authors.affiliation: Unidad de Bioinformática, Institut Pasteur Montevideo, Montevideo, Uruguay Departamento de Producción Animal y Pasturas, Facultad de Agronomía, Montevideo, Uruguay.
authors.forename: Hugo
authors.initials: H
authors.lastname: Naya
authors.affiliation: Laboratorio de Bacteriología, Unidad Integrada INTA-Universidad Nacional de Mar del Plata, Balcarce, Argentina.
authors.forename: Fernando
authors.initials: F
authors.lastname: Paolicchi
authors.affiliation: Unidad de Bioinformática, Institut Pasteur Montevideo, Montevideo, Uruguay.
authors.forename: Eugenia
authors.initials: E
authors.lastname: Pastor
authors.affiliation: Unidad de Bioinformática, Institut Pasteur Montevideo, Montevideo, Uruguay.
authors.forename: Sebastián
authors.initials: S
authors.lastname: Valenzuela
authors.affiliation: Sección Genética Evolutiva, Facultad de Ciencias, Montevideo, Uruguay.
authors.forename: Lucía
authors.initials: L
authors.lastname: Calleros
authors.affiliation: Laboratorio de Bacteriología, Unidad Integrada INTA-Universidad Nacional de Mar del Plata, Balcarce, Argentina.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Velilla
authors.affiliation: Sección Genética Evolutiva, Facultad de Ciencias, Montevideo, Uruguay.
authors.forename: Martín
authors.initials: M
authors.lastname: Hernández
authors.affiliation: Laboratorio de Bacteriología, Unidad Integrada INTA-Universidad Nacional de Mar del Plata, Balcarce, Argentina.
authors.forename: Claudia
authors.initials: C
authors.lastname: Morsella
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002167:Campylobacter / Q000145:classification / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity*; D002169:Campylobacter Infections / Q000382:microbiology*; D019143:Evolution, Molecular; D022761:Gene Transfer, Horizontal; D014644:Genetic Variation; D016680:Genome, Bacterial; D023281:Genomics; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny
chemical_list: D001426:Bacterial Proteins
keywords: Campylobacter; Campylobacter sputorum; comparative genomics; niche preferences; pathogenicity