Analysis of a novel virulence factor produced by Bordetella bronchiseptica

2015 Fiscal Year Final Research Report

• Project/Area Number: 26860288
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Bacteriology (including mycology)
• Research Institution: Osaka University
• Principal Investigator: NAKAMURA Keiji 大阪大学, 微生物病研究所, 特任研究員(常勤) (60706216)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: ボルデテラ属細菌 / 気管支敗血症菌 / バイオフィルム / 二成分制御系

Outline of Final Research Achievements

In the present study, the gene brtA (Bordetella RTX-family Adhesin), which was identified as one of genes expressed in B. bronchiseptica infecting host respiratory tracts, was characterized. Expression of virulence factors in Bordetella is mainly controlled by a two-component regulatory BvgAS system, which regulates a bacterial phase conversion between virulent Bvg+ and avirulent Bvg- phases. Immunoblotting and qRT-PCR analysis revealed that BrtA was expressed and secreted from the bacteria in the Bvg- phase. Furthermore, qRT-PCR confirmed that brtA was expressed in the bacteria colonizing rat trachea. Phenotypic analyses of a brtA-deficient strain demonstrated that BrtA is essential for adherence to plastic plate and is involved in biofilm formation of B. bronchiseptica. Although the role of brtA during Bordetella-infection remains to be elucidated, these results imply that the genes expressed in avirulent Bvg- phase may play a certain role in the course of infection.

Free Research Field

細菌学