FIG. 5.

Impact of the pil gene cluster on Y. pseudotuberculosis pathogenicity in the mouse model. BALB/c mice (groups of 10) were inoculated by the i.g. route with 10⁸ pil⁺ or pil mutant bacteria. The body weights and survival times of the infected animals were recorded during a 20-day period after bacterial challenge. The experiments were repeated twice, and very similar results were found. Representative data are shown. The bars represent the mean body weights of infected animals. Symbols: • and solid line, wild-type strain 32777 (pil⁺); ○ and dashed line, isogenic mutant MIV (pil mutant).