Fig 6.
V. parahaemolyticus ToxRS system is important for colonization of the adult mouse. A 1:1 mixed culture (1 × 109 CFU total) of WBWlacZ and a test strain were used to orogastrically infect streptomycin-treated adult mice. At 24 h postinfection, the entire gastrointestinal tracts were harvested, homogenized in PBS, and plated for CFU counting on LB plates containing 3% NaCl, streptomycin, and X-Gal. Data are reported as competitive index (CI), which is calculated as CI = ratio out(test strain/WBWlacZ)/ratio in(test strain/WBWlacZ). The solid line indicates the means. P values were calculated using a Kruskal-Wallis one-way ANOVA followed a Dunn's multiple-comparisons posttest. Asterisks denote significant differences between groups. *, P < 0.05; **, P < 0.001. WBW2467, ΔtoxRS strain ectopically expressing ompU (VP2467); ΔvscN1, T3SS-1 null mutant; ΔvscN2, T3SS-2 null mutant.