Abstract

Capsulated bacteria exhibit serum (complement) resistance and resistance to phagocytosis, which result in disseminated infections. Vibrio cholerae O139 strains possess a thin capsule and have been found to be partially serum resistant in a previous study. In the present study, compared to a standard capsulated Klebsiella pneumoniae strain, which showed total resistance to killing by phagocytosis, V. cholerae O139 strains were shown to be only partially resistant, with most strains showing <40% survival. These findings may explain the relative rarity of V. cholerae O139 bacteremia in cholera caused by this organism.