Table 1: Fifty Percent Lethal Dose (LD50) of B. anthracis, Y. pestis, and F. tularensis in Laboratory Animals Using Nasal Instillation

Animal Model B. anthracis Ames Spores (cfu) Y. pestis CO92 Cells (cfu) F. tularensis SCHU S4 Cells (cfu)
Swiss-Webster Mice 1.1 x 104 3.4 x 102 2.2 x 102
BALB/c Mice 1.7 x 104 1.0 x 102 3.3 x 101
Hartley Guinea Pigs 1.2 x 105 N.D. N.D.
Dutch-belted Rabbits 1.0 x 105 N.D. N.D.

N.D. = Not done.