Aggregatibacter actinomycetemcomitansarcB influences hydrophobic properties, biofilm formation and adhesion to hydroxyapatite

Author(s)

PL Longo ^[1] ; C Ota-Tsuzuki ^[2] ; ACR Nunes ^[3] ; BL Fernandes ^[4] ; K Mintz ^[5] ; P Fives-Taylor ^[6] ; MPA Mayer ^[7]

Affiliation

^[1] Universidade de São Paulo. Instituto de Ciências Biomédicas. Departamento de Microbiologia - Brasil

^[2] Universidade de São Paulo. Instituto de Ciências Biomédicas. Departamento de Microbiologia - Brasil

^[3] Universidade de São Paulo. Instituto de Ciências Biomédicas. Departamento de Microbiologia - Brasil

^[4] Universidade de São Paulo. Instituto de Ciências Biomédicas. Departamento de Microbiologia - Brasil

^[5] University of Vermont. Departament of Molecular Genetics - Estados Unidos

^[6] University of Vermont. Departament of Molecular Genetics - Estados Unidos

^[7] University of Vermont. Departament of Molecular Genetics - Estados Unidos

• Document type: Journal article
• Source: Brazilian Journal of Microbiology; v. 40, n. 3, p. 550-562, 2009-09-00.

Abstract

The regulation of gene expression in the oral pathogen Aggregatibacter actinomycetemcomitans is still not fully elucidated. ArcAB is a two-component system which allows facultative anaerobic bacteria to sense various respiratory growth conditions and adapt their gene expression accordingly. This study investigated in A. actinomycetemcomitans the role of arcB on the regulation of biofilm formation, adhesion to saliva coated hydroxyapatite (SHA) and the hydrophobic properties of the cell. These phenotypic traits were determined for an A. actinomycetemcomitansarcB deficient type and a wild type strain. Differences in hydrophobic properties were shown at early and late exponential growth phases under microaerobic incubation and at late exponential phase under anaerobiosis. The arcB mutant formed less biofilm than the wild type strain when grown under anaerobic incubation, but displayed higher biofilm formation activity under microaerobic conditions. The adherence to SHA was significantly lower in the mutant when compared with the wild type strain. These results suggest that the transmembrane sensor kinase arcB, in A. actinomycetemcomitans, senses redox growth conditions and regulates the expression of surface components of the bacterial cell related to biofilm formation and adhesion to saliva coated surfaces. (AU)

• FAPESP's process: 03/08598-0 - Virulence factors of A. actinomycetemcomitans: role in disease, expression regulation, diversity and immune response
• Grantee: Marcia Pinto Alves Mayer
• Support Opportunities: Research Projects - Thematic Grants