TABLE 1.

Cumulative frequencies of all mutations among Mycobacterium tuberculosis specimens resistant or susceptible to isoniazid

Gene(s)	Observed mutation(s) by gene location	No. of INHr specimens sequenced	No. of INHs specimens sequenced	No. of INHr specimens with mutation	No. of INHs specimens with mutation	Frequency of mutation among INHr specimens (%)a	Frequency of mutation among INHs specimens (%)b
katG only	315ACC	546	254	334	6	61.2	2.4
	315ACA	546	254	7	0	1.3	0.0
	315AAC	546	254	1	0	0.2	0.0
inhA only	−15T	553	277	24	1	4.3	0.4
	−17T	553	277	5	2	0.9	0.7
	−8C	553	277	2	0	0.4	0.0
ahpC only	−10A	542	287	3	0	0.6	0.0
	−6T	542	287	1	0	0.2	0.0
	−12A	542	287	1	0	0.2	0.0
	−9T	542	287	1	0	0.2	0.0
katG and inhA	315ACC/−15T	530	237	106	1	20.0	0.4
	315ACC/−17T	530	237	14	0	2.6	0.0
	315ACC/−8C	530	237	6	0	1.1	0.0
	315ACC/−8G	530	237	3	0	0.6	0.0
	315ACC/−8A	530	237	1	0	0.2	0.0
	315GGC/−15T	530	237	1	0	0.2	0.0
	315ACA/−8C	530	237	1	0	0.2	0.0
katG and ahpC	315ACC/−6T	526	235	4	0	0.8	0.0
	315ACC/−10A	526	235	3	0	0.6	0.0
	315ACC/−12A	526	235	1	0	0.2	0.0
	315ACC/−4A insertion	526	235	1	0	0.2	0.0
inhA and ahpC	−15T/−6T	528	263	1	0	0.2	0.0
	−15T/−10A	528	263	1	0	0.2	0.0
katG, inhA, or ahpC with no mutation	Wild type	516	225	26	222	5.0	98.7

^aFrequency of mutation among INH^r specimens was calculated as the number of INH^r specimens with the mutation/number of INH^r specimens sequenced.

^bFrequency of mutation among INH^s specimens was calculated as the number of INH^s specimens with the mutation/number of INH^s specimens sequenced.