Antagonism toward the intestinal microbiota and its effect on Vibrio cholerae virulence

Cholera pathogen zaps competition Many bacterial pathogens inject their hosts with virulence effectors delivered by specialist secretion machines. Vibrio cholerae has a type VI secretion system (T6SS) that can be loaded with protein toxins that target eukaryote host cells or kill competing bacteria. Zhao et al. discovered that mutant V. cholerae lacking a T6SS could not compete against Escherichia coli strains in the mouse gut. In contrast, intact V. cholerae readily gained a foothold in the gut of young mice, pumping up inflammatory immune responses and prompting more violent symptoms. Science , this issue p. 210