Fig. 7.

Marginal decrease in in vivo virulence of the ΔqseB mutant in a septicaemic mouse model of A. hydrophila infection. Swiss Webster mice were injected via the intraperitoneal route with 5×10⁷ c.f.u. of WT A. hydrophila SSU (n = 22; ▪). The same dose was used to infect mice with the ΔqseB mutant (n = 27; ▴), and both groups were monitored for death over a 16 day period. The percentage of surviving mice over time combined from three independent experiments is shown. The data were analysed by using Kaplan–Meier’s survival estimates showing statistically significant differences in animal survival between the ΔqseB mutant and the WT A. hydrophila SSU (P = 0.0058).