Figure 4. Mice infected with the bbfA mutant demonstrated a delay to death in comparison to those challenged with the parental strain.

Groups of six BALB/c mice were challenged via the intra-peritoneal route and the median time to death was determined by the Mantel-Cox log-rank test at 35 days post-infection. Mice inoculated with the bbfA mutant had a mean survival time of 3.5 days versus 2 days for those dosed with the wild-type (p = 0.03).