Fig 2.
ET and/or LT are required for virulence after an i.v. inoculation of rabbits with vegetative organisms. Survival after i.v. infection with fully capsulated, vegetative bacilli was assessed. (A) Rabbits were infected with 1.9 × 105 WT, 2.5 × 105 EF−, 2.7 × 105 LF−, or 2.9 × 105 PA− vegetative organisms/Rb (n = 3 Rb/strain). (B) Rabbits were infected with 1.3 × 105 WT, 2.2 × 105 EF−, 2.1 × 105 LF−, or 2.0 × 105 PA− organisms/Rb (n = 6 Rb/strain). At the end of the study, no bacteria were detectable in the spleens from rabbits infected with the PA− strain. Significant differences in survival curves were observed for rabbits infected with PA− versus WT, EF−, or LF− strains (P < 0.001) and WT versus EF− or LF− (P < 0.05) but not between rabbits infected with and LF− versus EF− strains (P = 0.23).