TABLE 1.

Median LD₅₀ of R. australis in wild-type C57BL/6 and MHC-I, IFN-γ, and perforin gene knockout mice

Strain of mice	Dilution of R. australis	No. of survivors/ total no. of mice	LD50 (PFU/mouse)
MHC-I KOa	10−5	0/6	10−6.34 (0.5)
	10−6	4/10
	10−7	8/10
	10−8	7/7
IFN-γ KO	10−3	0/10	10−3.71 (195)
	10−4	7/10
	10−5	10/10
Perforin KO	10−3	0/8	10−4.51 (31)
	10−4	1/7
	10−5	5/6
Wild-type C57BL/6	10−1	3/10	10−1.44 (3.6 × 104)
	10−2	8/10
	10−3	10/10

^aKO, knockout.