Differential complement activation and susceptibility to human serum bactericidal action by Vibrio species.

The ability of Vibrio vulnificus to resist human serum bactericidal action and to activate human complement was compared with similar cultures of Vibrio cholerae and Vibrio parahaemolyticus. Both V. vulnificus and V. parahaemolyticus had similar survival rates in sera and were much more resistant to killing than was V. cholerae. In contrast, V. vulnificus activated significantly less serum complement than did V. cholerae and V. parahaemolyticus. The relative ability of V. vulnificus to survive in serum and activate less complement than other Vibrio spp. tested may be related to its ability to cause chronic tissue infections and septicemias.