title: The FhaB/FhaC two-partner secretion system is involved in adhesion of Acinetobacter baumannii AbH12O-A2 strain.
abstract: Acinetobacter baumannii is a hospital-acquired pathogen that shows an extraordinary capacity to stay in the hospital environment. Adherence of the bacteria to eukaryotic cells or to abiotic surfaces is the first step for establishing an infection. The A. baumannii strain AbH12O-A2 showed an exceptional ability to adhere to A549 epithelial cells. The AbFhaB/FhaC 2-partner secretion (TPS) system involved in adhesion was discovered after the screening of the recently determined A. baumannii AbH12O-A2 strain genome (CP009534.1). The AbFhaB is a large exoprotein which transport to the bacterial surface is mediated by the AbFhaC protein. In the present study, the role of this TPS system in the AbH12O-A2 adherence phenotype was investigated. The functional inactivation of this 2-partner secretion system was addressed by analyzing the outer membrane vesicles (OMV) proteomic profile from the wild-type strain and its derivative mutant AbH12O-A2ΔfhaC demonstrating that AbFhaB is no longer detected in the absence of AbFhaC. Scanning electron microscopy (SEM) and adhesion experiments demonstrated that inactivation of the AbFhaB/FhaC system significantly decreases bacterial attachment to A549 alveolar epithelial cells. Moreover, it has been demonstrated that this 2-partner secretion system is involved in fibronectin-mediated adherence of the A. baumannii AbH12O-A2 isolate. Finally, we report that the AbFhaB/FhaC system is involved in virulence when tested using invertebrate and vertebrate hosts. These data suggest the potential role that this AbFhaB/FhaC secretion system could play in the pathobiology of A. baumannii.
authors.affiliation: a Departamento de Microbiología , Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), Universidad da Coruña (UDC) , A Coruña , Spain.|b Departamento de Microbiología y Parasitología , Universidad de Santiago de Compostela (USC) , Santiago de Compostela , Spain.|c Department of Microbiology , Miami University , Oxford , OH , USA.
authors.forename: A
authors.initials: A
authors.lastname: Pérez
authors.affiliation: a Departamento de Microbiología , Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), Universidad da Coruña (UDC) , A Coruña , Spain.
authors.forename: M
authors.initials: M
authors.lastname: Merino
authors.affiliation: a Departamento de Microbiología , Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), Universidad da Coruña (UDC) , A Coruña , Spain.
authors.forename: S
authors.initials: S
authors.lastname: Rumbo-Feal
authors.affiliation: a Departamento de Microbiología , Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), Universidad da Coruña (UDC) , A Coruña , Spain.
authors.forename: L
authors.initials: L
authors.lastname: Álvarez-Fraga
authors.affiliation: a Departamento de Microbiología , Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), Universidad da Coruña (UDC) , A Coruña , Spain.
authors.forename: J A
authors.initials: JA
authors.lastname: Vallejo
authors.affiliation: a Departamento de Microbiología , Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), Universidad da Coruña (UDC) , A Coruña , Spain.
authors.forename: A
authors.initials: A
authors.lastname: Beceiro
authors.affiliation: c Department of Microbiology , Miami University , Oxford , OH , USA.
authors.forename: E J
authors.initials: EJ
authors.lastname: Ohneck
authors.affiliation: d Grupo de Proteómica-ProteoRed/Plataforma PBR2-ISCIII, Servicio de Reumatología, Instituto de Investigación Biomédica de A Coruña (INIBIC), Complejo Hospitalario Universitario de A Coruña (CHUAC), Universidade da Coruña (UDC) , A Coruña , Spain.|e Marine Research Institute, Consejo Superior de Investigaciones Científicas (CSIC) , Vigo , Spain.
authors.forename: J
authors.initials: J
authors.lastname: Mateos
authors.affiliation: d Grupo de Proteómica-ProteoRed/Plataforma PBR2-ISCIII, Servicio de Reumatología, Instituto de Investigación Biomédica de A Coruña (INIBIC), Complejo Hospitalario Universitario de A Coruña (CHUAC), Universidade da Coruña (UDC) , A Coruña , Spain.
authors.forename: P
authors.initials: P
authors.lastname: Fernández-Puente
authors.affiliation: c Department of Microbiology , Miami University , Oxford , OH , USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Actis
authors.affiliation: a Departamento de Microbiología , Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), Universidad da Coruña (UDC) , A Coruña , Spain.
authors.forename: M
authors.initials: M
authors.lastname: Poza
authors.affiliation: a Departamento de Microbiología , Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), Universidad da Coruña (UDC) , A Coruña , Spain.
authors.forename: G
authors.initials: G
authors.lastname: Bou
mesh_terms: D000072283:A549 Cells; D000151:Acinetobacter Infections / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000378:metabolism / Q000472:pathogenicity*; D018829:Adhesins, Bacterial / Q000378:metabolism*; D001422:Bacterial Adhesion; D004847:Epithelial Cells / Q000382:microbiology; D006801:Humans; D008855:Microscopy, Electron, Scanning; D040901:Proteomics; D000069320:Type V Secretion Systems / Q000378:metabolism*; D014774:Virulence
chemical_list: D018829:Adhesins, Bacterial; D000069320:Type V Secretion Systems
keywords: Acinetobacter baumannii; adherence; proteomics; two-partner secretion system