Table 1.

Genes associated with drug resistance and mutation frequency for each gene in clinical isolates of Mycobacterium tuberculosis

Group	Drug	Gene associated with drug resistance	Mutation frequency in isolates (%)
First line anti-TB drugs	Rifampicin (R)	rpoB encoding for β-subunit of RNA polymerase	90–100
	Isoniazid (H)	katG encoding for catalase-peroxidase	40–97
		inhA encoding for fatty acid enoyl acyl carrier protein reductase A (InhA)	8–64
	Ethambutol (E)	embB encoding for arabinosyl transferase	47–89
	Pyrazinamide (Z)	pncA encoding for pyrazinamidase	44–97
	Streptomycin (S)	rrs encoding for 16S rRNA subunit	12–26
		rpsL encoding for S12 ribosomal protein	40–68
		gidB encoding for 7-methylguanosine methyltransferase	5–13
Second line anti-TB drugs	Amikacin, Kanamycin, Capreomycin	rrs encoding for 16S rRNA	40–90
	Kanamycin	eis encoding for aminoglycoside acetyltransferase	28–80
	Capreomycin	tlyA encoding for 2′-O- methyltransferase	4–13
	Ofloxacin, levofloxacin, moxifloxacin, gatifloxacin	gyrA encoding for DNA gyrase subunit A	70–90
		gyrB encoding for DNA gyrase subunit B	0–11
	Ethionamide	inhA encoding for fatty acid enoyl acyl carrier protein reductase A (InhA)	33–62
		ethA encoding for EthA	46–72
		ethR encoding for transcriptional repressor EthR, NADH-ACP	0–4