FIG. 5.

Pathogenicity of the Yts1 secreton for mice (oral inoculation). BALB/c mice (five per group) were orally challenged with 5 × 10⁹ Y. enterocolitica. At 48 h after infection, mice were sacrificed, and the bacterial load was determined by plating the intestinal lavage (SI) and tissue homogenates from Peyer's patches (PP), liver (L), and spleen (SP). (A) Comparison of mice infected with strain WA-314 (wt) and yts1E mutant; (B) comparison of mice infected with reconstituted wild-type strain (rwt) harboring an intact yts1E gene (after gene replacement of the kanamycin-inactivated yts1E gene with the wild-type parental allele) and with the yts1E mutant. Values are means for five animals, with the standard error of the means indicated by an error bar.