Evidence for phenotypic bistability resulting from transcriptional interference of bvgAS in Bordetella bronchiseptica.

ABSTRACT: Bordetella species cause respiratory infections in mammals. Their master regulatory system BvgAS controls expression of at least three distinct phenotypic phases in response to environmental cues. The Bvg⁺ phase is necessary and sufficient for respiratory infection while the Bvg⁻ phase is required for survival ex vivo. We obtained large colony variants (LCVs) from the lungs of mice infected with B. bronchiseptica strain RBX9, which contains an in-frame deletion mutation in fhaB, encoding filamentous haemagglutinin. RBX9 also yielded LCVs when switched from Bvg⁻ phase conditions to Bvg⁺ phase conditions in vitro. We determined that LCVs are composed of both Bvg⁺ and Bvg⁻ phase bacteria and that they result from defective bvgAS positive autoregulation. The LCV phenotype was linked to the pre

SUBMITTER: Mason E 

PROVIDER: S-EPMC4216693 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature