Fig 5. Median lethal dose determination of WT B. mallei and bpaB KO mutant strains.

Mice were inoculated intratracheally using a Microsprayer device to aerosolize the indicated number of bacterial CFU directly into the lungs (n = 5 mice/dose). Animals were then monitored daily for clinical signs of illness and morbidity. Panel A: Survival curves. Panel B: Calculated LD₅₀ values. Panels C and D: Tissues were collected from mice that survived challenge with 10² CFU, homogenized, diluted, and spread on agar plates to determine bacterial loads. Symbols show data for individual animals.