FIG 3.

Effect of CpxR activation on the recovery of Vibrio cholerae on TCBS agar. The V. cholerae WT, cpxA* mutant, and ΔcpxR mutant were cultured in LB broth or LB broth containing 2 M KCl before aliquots were diluted in PBS and plated in duplicate onto LB agar and TCBS agar plates for enumeration. The plates were incubated overnight at 37°C before the resulting colonies were counted. The recovery ratio for each mutant was calculated by the following equation: (the number of mutant colonies on TCBS/the number of mutant colonies on LB agar)/(the number of WT colonies on TCBS/the number of WT colonies on LB agar). The values are the means of results of three independent experiments ± SD. Statistical significance relative to WT values was determined by ANOVA with the Tukey-Kramer multiple-comparison test. *, P < 0.001.