Table 3.

Gene mutations conferring INH resistance identified by the MTBDRplus assay

Conventional DSTb (no. of slides)	No. (%) of slides	MTBDRplus assaya
		INH pattern (katG)	INH pattern (inhA)	Mutation or mutated codon (katG)	Mutation or mutated codon (inhA)
INHr (55)	39 (66.1)	ΔWT, MUT1	WT	S315T	WT
	1 (1.69)	WT, MUT1	WT	S315T	WT
	3 (5.08)	ΔWT	WT	315	WT
	11 (18.64)	WT	ΔWT1, MUT1	WT	C15T
	1 (1.69)	ΔWT, MUT1	ΔWT1, MUT1	S315T	C15T
INHs (4)	1 (1.69)	WT	ΔWT1, MUT1	WT	C15T
	1 (1.69)	WT, MUT1	WT	S315T	WT
	2 (3.39)	ΔWT1, MUT1	WT	S315T	WT

^aWT, wild-type pattern; Δ, missing bands; MUT, mutation.

^bINH^r, isoniazid resistant; INH^s, isoniazid susceptible.