Two-component systems in Haemophilus influenzae: a regulatory role for ArcA in serum resistance.

ABSTRACT: Knockout mutations were constructed in the arcA gene of a virulent type b strain of Haemophilus influenzae, and the behavior of the resulting mutants was investigated in a number of conditions that mimicked distinct steps in the natural infection pathway. In arcA mutants, synthesis of capsule and lipooligosaccharide (LOS) and growth in synthetic media were unaltered compared to synthesis of capsule and LOS and growth in synthetic media in the wild-type H. influenzae type b parent strain. However, the virulence of the arcA mutants for BALB/c mice was significantly reduced. Upon exposure to human blood or serum, the arcA mutants showed markedly reduced survival compared with the survival of its wild-type parent. Serum resistance could be fully restored by complementation in cis with the H. i

SUBMITTER: De Souza-Hart JA 

PROVIDER: S-EPMC143216 | biostudies-literature | 2003 Jan

REPOSITORIES: biostudies-literature