Discrepancies in Drug Susceptibility Test for Tuberculosis Patients Resulted from the Mixed Infection and the Testing System

Table 4

MIC of INH and the katG, inhA, and oxyR-ahpC mutations of the 20 pairs of M. tuberculosis isolates with DST discrepancies.

Pairs	Isolate^*	7H9 Middlebrook (g/mL)	L-J agar (g/mL)	katG315	inhA reg	inhA ORF	oxyR-ahpC
1	2235	0.6	1	AAC	None	None	None
	3010	0.6	1	AAC	None	None	None
2	3195	0.1	1	AGC	None	None	None
	2986	0.1	1	AGC	None	None	None
3	3184	0.4	0.6	ACC	None	None	None
	3255	0.4	0.6	ACC	None	None	None
4	2577	0.2	0.4	AGC	None	None	None
	549	0.2	0.4	AGC	None	None	None
5	3478	0.6	1.2	ACC	None	None	None
	3972	0.6	1.2	ACC	None	None	None
6	322	0.4	1	ACC	None	None	None
	501	0.2	0.6	ACC	None	None	None
7	2671	0.6	1.2	AGC	None	None	None
	1182	0.4	1	AGC	None	None	None
8	2851	0.4	1	AAC	None	None	None
	1563	0.4	1	AAC	None	None	None
9	2566	0.4	1	ACC	None	None	None
	497	0.4	1	ACC	None	None	None
10	3079	0.6	1.4	AGC	None	None	None
	2435	0.6	1.4	AGC	None	None	None
11	3995	0.4	1	ACC	None	None	None
	4835	0.4	1	ACC	None	None	None
12	4394	0.4	0.8	ACC	None	None	None
	4396	0.4	0.8	ACC	None	None	None
13	4124	1	1.4	AAC	None	None	None
	4198	1	1.4	AAC	None	None	None
14	4192	0.4	1	ACC	None	None	None
	4199	0.4	1	ACC	None	None	None
15	4348	0.2	0.8	ACC	None	None	None
	4355	0.2	0.8	ACC	None	None	None
16	4482	0.4	1	AGC	None	None	None
	1901	0.4	1	AGC	None	None	None
17	4484	1	1.8	ACC	None	None	None
	1914	1	1.8	ACC	None	None	None
18	2098	0.4	1	AGC	None	None	None
	2099	0.4	1	AAC	None	None	None
19	2785	0.4	1	AAC	None	None	None
	1554	0.4	1	AAC	None	None	None
20	2789	0.2	0.6	AGC	None	None	None
	1344	0.2	0.6	AGC	None	None	None

Note: katG315 is the predominant mutation. The wild type is AGC.
^*16 isolates with consistent genotype in pair and 4 pairs of isolates (bold) with different genotypes in pair.