title: Analysis of the role of the LH92_11085 gene of a biofilm hyper-producing Acinetobacter baumannii strain on biofilm formation and attachment to eukaryotic cells.
abstract: Acinetobacter baumannii is a nosocomial pathogen that has a considerable ability to survive in the hospital environment partly due to its capacity to form biofilms. The first step in the process of establishing an infection is adherence of the bacteria to target cells. Chaperone-usher pili assembly systems are involved in pilus biogenesis pathways that play an important role in adhesion to host cells and tissues as well as medically relevant surfaces. After screening a collection of strains, a biofilm hyper-producing A. baumannii strain (MAR002) was selected to describe potential targets involved in pathogenicity. MAR002 showed a remarkable ability to form biofilm and attach to A549 human alveolar epithelial cells. Analysis of MAR002 using transmission electron microscopy (TEM) showed a significant presence of pili on the bacterial surface. Putative protein-coding genes involved in pili formation were identified based on the newly sequenced genome of MAR002 strain (JRHB01000001/2 or NZ_JRHB01000001/2). As assessed by qRT-PCR, the gene LH92_11085, belonging to the operon LH92_11070-11085, is overexpressed (ca. 25-fold more) in biofilm-associated cells compared to exponential planktonic cells. In the present work we investigate the role of this gene on the MAR002 biofilm phenotype. Scanning electron microscopy (SEM) and biofilm assays showed that inactivation of LH92_11085 gene significantly reduced bacterial attachment to A549 cells and biofilm formation on plastic, respectively. TEM analysis of the LH92_11085 mutant showed the absence of long pili formations normally present in the wild-type. These observations indicate the potential role this LH92_11085 gene could play in the pathobiology of A baumannii.
authors: a Departamento de Microbiología , Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), Universidad de A Coruña (UDC) , A Coruña , Spain.
authors: Laura
authors: L
authors: Álvarez-Fraga
authors: a Departamento de Microbiología , Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), Universidad de A 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: Astrid
authors: A
authors: Pérez
authors: a Departamento de Microbiología , Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), Universidad de A Coruña (UDC) , A Coruña , Spain.
authors: Soraya
authors: S
authors: Rumbo-Feal
authors: a Departamento de Microbiología , Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), Universidad de A Coruña (UDC) , A Coruña , Spain.
authors: María
authors: M
authors: Merino
authors: a Departamento de Microbiología , Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), Universidad de A Coruña (UDC) , A Coruña , Spain.
authors: Juan Andrés
authors: JA
authors: Vallejo
authors: c Department of Microbiology , Miami University , Oxford , OH , USA.
authors: Emily J
authors: EJ
authors: Ohneck
authors: d Center for Advanced Microscopy and Imaging, Miami University , Oxford , OH , USA.
authors: Richard E
authors: RE
authors: Edelmann
authors: a Departamento de Microbiología , Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), Universidad de A Coruña (UDC) , A Coruña , Spain.
authors: Alejandro
authors: A
authors: Beceiro
authors: a Departamento de Microbiología , Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), Universidad de A Coruña (UDC) , A Coruña , Spain.
authors: Juan C
authors: JC
authors: Vázquez-Ucha
authors: e Departamento de Biofilms Microbianos , Instituto de Agrobiotecnología , Navarra , Spain.
authors: Jaione
authors: J
authors: Valle
authors: 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: Luis A
authors: LA
authors: Actis
authors: a Departamento de Microbiología , Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), Universidad de A Coruña (UDC) , A Coruña , Spain.
authors: Germán
authors: G
authors: Bou
authors: a Departamento de Microbiología , Instituto de Investigación Biomédica (INIBIC), Complejo Hospitalario Universitario (CHUAC), Universidad de A Coruña (UDC) , A Coruña , Spain.
authors: Margarita
authors: M
authors: Poza
mesh_terms: D000072283:A549 Cells; D040981:Acinetobacter baumannii / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology* / Q000648:ultrastructure; D056809:Alveolar Epithelial Cells / Q000382:microbiology; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development*; D010861:Fimbriae, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D006801:Humans; D008855:Microscopy, Electron, Scanning; D014774:Virulence / Q000235:genetics
chemical_list: D001426:Bacterial Proteins
keywords: acinetobacter baumannii; attachment; biofilm; pathogenicity; pili; virulence