TABLE 4.

Dissemination of cryptococcal infection via infected lung IM compared with cryptococci cultured from them^a

Strain	No. of IM in donor mice at 6 days, prior to transfer	Cryptococcal CFU in pooled donor IM	CFU in donor brains	Cryptococcal load (mean CFU/g of tissue ± SEM) in mouse tissue (no. of infected mice/total no. of mice)		Cryptococcal load (mean CFU/g of tissue ± SEM) in mouse tissue (no. of infected mice/total no. of mice)
				5 days after IM transfers by tail vein injection (recipients)b		11 days after endotracheal infection (donors)c		5 days after tail vein injection, cultured from IM (recipients)d
				Lung	Brain	Lung	Brain	Lung	Brain
Δplb1	2.3 × 106	3.62 × 103	0	4.17 × 103 ± 2.41 × 103 (3/3)	0.32 × 103 ± 0.18 × 103 (2/3)	30.13 × 106 ± 8.36 × 106 (5/5)	—h	0.19 × 103 ± 0.1 × 103 (3/4)	9.11 × 103 ± 5.74 × 103 (3/4)
BL-1a	1.4 × 106	12.06 × 103	—h	11.48 × 103 ± 10.90 × 103 (2/3)	77.22 × 103 ± 21.89 × × 103 (3/3)e	72.52 × 106 ± 13.36 × 106 (5/5)f	0.93 × 103 ± 0.65 × 103 (3/5)g	—h	3.74 × 103 ± 2.98 × 103 (4/4)g

^aDonor mice were inoculated endotracheally with 3 × 10⁷ cells. Recipient mice were inoculated with IM containing 904 CFU of Δplb1 or 3,016 CFU of BL-1a or with the same number of cryptococci derived from these IM.

^bData are for three mice.

^cData are for five mice.

^dData are for four mice.

^eSignificantly different from Δplb1 (P < 0.05 by two-tailed unpaired t test).

^fSignificantly different by the Mann-Whitney U test.

^gSignificant (P ≤ 0.01) difference from the same cryptococci in the same tissue in recipient mice 5 days after IM transfer by the two-tailed unpaired t test and also (P ≤ 0.05) by the Mann-Whitney U test. In control experiments, no cryptococci were cultured from brains of animals injected intravenously with either BL-1a or Δplb1 strains.

^h—, CFU were present in only one mouse, and mean data are not available.