TABLE 2.

Reproducibility data generated at the six study sites (phase II) during AST of 20 strains of M. tuberculosis

Drug	Strain categorya (no. of strains)	Test system	Inhibitory concn (μg/ml)	No. of cultures at site:						Total no. of cultures
				1	2	3	4	5	6
Capreomycin	S (14)	BACTEC 460	≤1.25	14	13	14	11	7	13	72
			2.5	0	1	0	2	7	0	10
			5	0	0	0	1	0	1	2
		Middlebrook 7H10	≤10.0	13	13	12c	14	14	12	78
	R (6)	BACTEC 460	>5.0	6	6	6	6	6	6	36
		Middlebrook 7H10	>10.0	6	6	1	6	0c	6	25
Cycloserine	S (20)	BACTEC 460	≤75	20	20	18	17	14	—b	89
			100	0	0	1	3	5	—	9
			200	0	0	1	0	1	—	2
		Middlebrook 7H10	≤30	19	20	18	18	16	—	91
Ethionamide	S (10)	BACTEC 460	≤0.625	6	6	6	3	3	5	29
			1.25	3	4	4	6	6	5	28
			2.5	1	0	0	1	1	0	3
		Middlebrook 7H10	≤5.0	7	9	10	10	10	9	55
	R (10)	BACTEC 460	≤0.625	0	0	0	0	1	0	1
			1.25	1	2	1	1	1	0	6
			2.5	2	2	1	2	2	1	10
			>2.5	7	6	8	7	6	9	43
		Middlebrook 7H10	≥5.0	10	9	2c	10	4c	2	37
Kanamycin	S (11)	BACTEC 460	≤1.25	8	7	7	6	7	8	43
			2.5	3	4	4	5	4	3	23
		Middlebrook 7H10	≤5.0	11	11	11	11	11	10	65
	R (9)	BACTEC 460	≤1.25	0	0	1	0	1	3	1
			2.5	1	1	0	1	0	0	3
			5	8	8	8	8	8	8	48
		Middlebrook 7H10	≥5.0	9	9	9	9	7	9	52
Amikacin	S (12)	BACTEC 460	≤0.5	12	12	11c	12	12	12	71
		Middlebrook 7H10	≤2.0	11	11	11	10	12	12	67
			4.0	0	0	0	1	0	0	1
			>4.0	1	1	1	1	0	0	4
	R (8)	BACTEC 460	>2.0	8	8	8	8	8	8	48
		Middlebrook 7H10	>4.0	8	8	8	8	7c	8	47
Clofazimine	S (19)	BACTEC 460	≤0.125	13	19	18	19	18	19	106
			0.25	6	0	1	0	1	0	8
		Middlebrook 7H10	≤0.5	19	19	18c	19	18c	17	110
			1	0	0	0	0	0	2	2
	R (1)	BACTEC 460	≤0.125	0	0	0	1	0	0	1
			0.5	0	1	1	0	1	0	3
			>0.5	1	0	0	0	0	1	2
		Middlebrook 7H10	≤0.5	0	0	1	1	1	0	3
			1.0	1	1	0	0	0	0	2
			>1.0	0	0	0	0	0	1	1
Ofloxacin	S (19)	BACTEC 460	≤1.0	16	15	14	16	18	15	94
			2.0	3	4	5	3	1	4	20
		Middlebrook 7H10	≤1.0	18	19	17c	14	18c	12	98
			2.0	1	0	1	5	0	7	14
	R (1)	BACTEC 460	4.0	1	0	0	0	0	0	1
			>4.0	0	1	1	1	1	1	5
		Middlebrook 7H10	>4.0	1	1	1	1	1	1	6
Rifabutin	S (7)	BACTEC 460	≤0.5	6	6	6	7	7	7	39
			1.0	1	1	1	0	0	0	3
		Middlebrook 7H10	≤0.5	7	7	7	7	7	7	42
	R (13)	BACTEC 460	1.0	1	1	0	0	1	1	4
			2.0	0	0	1	1	0	0	2
			>2.0	12	12	12	12	12	12	72
		Middlebrook 7H10	≤0.5	1	1	0	0	1	1	4
			1.0	0	0	0	1	2	0	3
			2.0	0	0	3	0	2	0	5
			>2.0	12	12	9c	12	5c	12	62

^aS, susceptible; R, resistant. 

^bSite 6 was excluded (see Results). 

^cResults of some susceptibility tests are missing.