title: Analysis of prophages harbored by the human-adapted subpopulation of Staphylococcus aureus CC398.
abstract: Staphylococcus aureus clonal complex 398 is a livestock-associated pathogen that poses a worldwide threat because of its ability to colonize and infect both humans and animals. We used high-resolution whole-genome microarrays, prophage profiling, immune evasion cluster characterization and whole-genome sequencing to investigate the roles of prophages in the emerging human-adapted subpopulation of CC398 that has been associated with invasive infections in humans living in animal-free environments. We characterized one phage and two prophages specifically harbored by CC398 isolates belonging to the emerging subpopulation. We introduced the phage into permissive prophage-free isolates. We investigated the effects of lysogeny on the host ability to resist further phage infection and transformation, to acquire the capacity to invade human cells, and to express virulence factors encoded by prophages. We report evidence of a defective ϕMR11-like helper prophage, named StauST398-5pro, specifically associated with the emerging non-LA CC398 subpopulation. StauST398-5pro confers substantial protection against horizontal genetic transfer to its host. It interacts with a human-associated β-converting prophage encoding immune-modulating proteins such that virulence genes are expressed during stress situations. Our findings provide insight into the role of phages in the expression of virulence and in the spread of genetic information among new host-adapted S. aureus isolates. We demonstrate that functional prophage elements can condition host specificity and confer new virulence traits on emerging intra-species clones of bacteria.
authors.affiliation: Service de Bactériologie et Hygiène, Centre Hospitalier Régional Universitaire, F37044 Tours Cedex, France. n.vandermee@chu-tours.fr
authors.forename: Nathalie
authors.initials: N
authors.lastname: van der Mee-Marquet
authors.forename: Anna-Rita
authors.initials: AR
authors.lastname: Corvaglia
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Valentin
authors.forename: David
authors.initials: D
authors.lastname: Hernandez
authors.forename: Xavier
authors.initials: X
authors.lastname: Bertrand
authors.forename: Myriam
authors.initials: M
authors.lastname: Girard
authors.forename: Jan
authors.initials: J
authors.lastname: Kluytmans
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Donnio
authors.forename: Roland
authors.initials: R
authors.lastname: Quentin
authors.forename: Patrice
authors.initials: P
authors.lastname: François
mesh_terms: D000818:Animals; D016009:Chi-Square Distribution; D024881:Drug Resistance, Bacterial; D057809:HEK293 Cells; D058507:Host Specificity; D006801:Humans; D058751:Livestock; D008242:Lysogeny; D020411:Oligonucleotide Array Sequence Analysis; D039002:Prophages / Q000235:genetics*; D013203:Staphylococcal Infections / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000145:classification / Q000235:genetics / Q000821:virology*; D014774:Virulence; D015047:Zoonoses / Q000382:microbiology*
keywords: Host specificity; Prophage; Sequence type 398; Staphylococcus aureus; Virulence