FIG. 1.

Competition assays in infant mice between LacZ⁺ V. cholerae N16961 and LacZ⁻ V. cholerae KFV10 grown in various conditions prior to competition in CD-1 infant mice. (a) LacZ⁺ versus LacZ⁻ V. cholerae, both grown to stationary phase in LB; (b) mouse-passaged LacZ⁺ V. cholerae versus LacZ⁻ V. cholerae grown to stationary phase in LB; (c) mouse-passaged LacZ⁺ V. cholerae versus LacZ⁻ V. cholerae grown to exponential phase in LB; (d) mouse-passaged LacZ⁺ V. cholerae versus LacZ⁻ V. cholerae grown overnight in AKI conditions. Each data point represents the competitive index (CI) from a single animal. The flat bars indicate the median of the CIs for each experiment. By the unpaired t test, the results of experiments b to d each differed significantly from those for experiment a (P < 0.04).