CHARACTERIZATION OF BRKA EXPRESSION IN BORDETELLA-BRONCHISEPTICA

BrkA confers resistance to killing by complement in Bordetella pertuss is. Complement resistance in Bordetella bronchiseptica was examined. F our B. bronchiseptica strains possessed the brkA gene; however, only t hree expressed the protein. Only the strain lacking BrkA was susceptib le to complement. Introduction of the B. pertussis brkA gene restored BrkA expression to this strain but did not confer resistance. brkA was mutated in the strains that naturally expressed BrkA, and loss of Brk A did not confer sensitivity to complement. As a species, B. bronchise ptica is more resistant to complement than B. pertussis, and BrkA does not mediate resistance.