TABLE 1.

Results for rabbits given aerosol doses of different M. tuberculosis strains

Expt no.a	Strainb	Mean impinger dose (CFU/ml) ± SD	Mean inhaled dose (CFU/ml) ± SE	Log10 inhaled bacilli	Mean no. of tubercles at 5 wk	Mean tubercle diameter (mm) ± SE	No. of bacilli inhaled/tubercle
1	H37Rv	121,250 ± 16,530	393,330 ± 63,180	5.59	278 ± 65	2.3 ± 0.1	1,415
2	H37Rv	31,170 ± 3,820	60,050 ± 4,950	4.78	81 ± 21	1.6 ± 0.2	741
3	H37Rv	105,000 ± 6,190	410,000 ± 78,300	5.61	217 ± 53	1.6 ± 0.2	1,889
4	H37Rv	24,880 ± 2,490	38,880 ± 6,230	4.58	65 ± 10	2.2 ± 0.2	598
5a	H37Rv		7,930 ± 1,340	3.90	8 ± 4	1.9 ± 0.2	991
5b	CDC1551	600	8,500 ± 1,730	3.92	5.1 ± 1.5	1.2 ± 0.2	1,667
6	CDC1551(f)	14,100 ± 1,670	53,600 ± 6,570	4.73	3 ± 0.8	0.8 ± 0.1	17,867
7	Erdman	134,170 ± 16,700	309,300 ± 46,440	5.49	374 ± 97	1.93 ± 0.1	827
8a	Erdman	12,170 ± 2,090	75,000 ± 20,980	4.87	210 ± 44	1.5 ± 0.1	357
8b	Erdman(f)	329,440 ± 8,870	1,231,670 ± 196,940	6.09	353 ± 60	1.7 ± 0.1	3,489
9	Erdman	29,670 ± 1,930	63,700 ± 7,050	4.80	94 ± 19	1.5 ± 0.1	678
10	Erdman	34,330 ± 9,420	60,470 ± 20,560	4.78	189 ± 51	2.0 ± 0.4	320
11	Erdman(f)	52,330 ± 13,310	113,830 ± 32,690	5.06	135 ± 23	2.8 ± 0.3	843

^aThe number of rabbits per experiment was six, except for experiment 6, which had 12. Experiments 1 to 5 have been described previously (3, 10).

^b(f), frozen thawed inoculum. All others were grown to logarithmic phase in 7H9 Middlebrook broth.