title: Genomics and Proteomics Provide New Insight into the Commensal and Pathogenic Lifestyles of Bovine- and Human-Associated Staphylococcus epidermidis Strains.
abstract: The present study reports comparative genomics and proteomics of Staphylococcus epidermidis (SE) strains isolated from bovine intramammary infection (PM221) and human hosts (ATCC12228 and RP62A). Genome-level profiling and protein expression analyses revealed that the bovine strain and the mildly infectious ATCC12228 strain are highly similar. Their genomes share high sequence identity and synteny, and both were predicted to encode the commensal-associated fdr marker gene. In contrast, PM221 was judged to differ from the sepsis-associated virulent human RP62A strain on the basis of distinct protein expression patterns and overall lack of genome synteny. The 2D DIGE and phenotypic analyses suggest that PM221 and ATCC12228 coordinate the TCA cycle activity and the formation of small colony variants in a way that could result in increased viability. Pilot experimental infection studies indicated that although ATCC12228 was able to infect a bovine host, the PM221 strain caused more severe clinical signs. Further investigation revealed strain- and condition-specific differences among surface bound proteins with likely roles in adhesion, biofilm formation, and immunomodulatory functions. Thus, our findings revealed a close link between the bovine and commensal-type human strains and suggest that humans could act as a reservoir of bovine mastitis-causing SE strains.
authors.forename: Kirsi
authors.initials: K
authors.lastname: Savijoki
authors.forename: Antti
authors.initials: A
authors.lastname: Iivanainen
authors.forename: Pia
authors.initials: P
authors.lastname: Siljamäki
authors.forename: Pia K
authors.initials: PK
authors.lastname: Laine
authors.forename: Lars
authors.initials: L
authors.lastname: Paulin
authors.forename: Taru
authors.initials: T
authors.lastname: Karonen
authors.forename: Satu
authors.initials: S
authors.lastname: Pyörälä
authors.affiliation: CSC - IT Center for Science Ltd. , FI-02101 Espoo, Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Kankainen
authors.forename: Tuula A
authors.initials: TA
authors.lastname: Nyman
authors.forename: Tiina
authors.initials: T
authors.lastname: Salomäki
authors.forename: Patrik
authors.initials: P
authors.lastname: Koskinen
authors.forename: Liisa
authors.initials: L
authors.lastname: Holm
authors.forename: Heli
authors.initials: H
authors.lastname: Simojoki
authors.forename: Suvi
authors.initials: S
authors.lastname: Taponen
authors.forename: Antti
authors.initials: A
authors.lastname: Sukura
authors.forename: Nisse
authors.initials: N
authors.lastname: Kalkkinen
authors.forename: Petri
authors.initials: P
authors.lastname: Auvinen
authors.forename: Pekka
authors.initials: P
authors.lastname: Varmanen
keywords: 2D DIGE; Genomics; Staphylococcus epidermidis; adaptation; intramammary infection; surfacome shaving; virulence