IN-VIVO AND IN-VITRO ANALYSIS OF BORDETELLA-PERTUSSIS CATALASE AND FE-SUPEROXIDE DISMUTASE MUTANTS

Bordetella pertussis produces a catalase and a Fe-superoxide dismutase . The importance of these enzymes in virulence was investigated, in vi tro as well as in vivo, by using mutants deficient in their production . The catalase-deficient mutant survived within polymorphonuclear leuk ocytes, killed J774A.1 macrophages through apoptosis, and behaved as t he parental strain in a murine respiratory infection model. These resu lts suggest no direct role for catalase in B. pertussis virulence. The absence of expression of Fe-superoxide dismutase had profound effects on the bacterium including a reduced ability to express adenylate cyc lase-hemolysin and pertactin, two factors important for B. pertussis p athogenesis. The Fe-superoxide dismutase-deficient mutant also had dec reased abilities to colonize and persist in the murine respiratory inf ection model.