Fig 5.

Serum from mice immunized with rApfA afforded passive protection against lethal challenges with strain 4074 (serovar 1) and strain WF83 (serovar 7). Serum against rApfA or bacterin significantly increased the survival rates after a challenge with (A) strain 4074 (serovar 1) or (B) strain WF83 (serovar 7), while control mice immunized with serum from adjuvant-immunized mice all succumbed to infection. The data shown shown are representative of the results of one of three independent experiments; the survival data were analyzed using the log rank (Mantel-Cox) test. The asterisks show significant differences (*, P < 0.05; **, P < 0.01).