Construction and virulence testing of a collagenase mutant of Clostridium perfringens

Clostridium perfringens produces several extracellular toxins and enzymes, including an extracellular collagenase or kappa toxin that is encoded by th e colA gene. To determine if the ability to produce collagenase was a signi ficant virulence factor in cases of gas gangrene or clostridial myonecrosis that are caused by C. perfringens, a chromosomal colA mutant was construct ed by homologous recombination and subsequently virulence tested in the mou se myonecrosis model. The results clearly indicate that loss of the ability to produce collagenase does not alter the ability of the mutant to establi sh a virulent infection. By contrast, infection with a mutant unable to pro duce alpha-toxin led to a marked decrease in virulence. These results indic ate that collagenase is not a major determinant of virulence in C. perfring ens-mediated clostridial myonecrosis. (C) 2000 Academic Press.