Drug Resistance in Tuberculous Lymphadenitis: Molecular Characterization

Table 3

Common gene mutations observed in isoniazid and rifampicin-resistant MTB strains isolated from TB lymphadenitis patients in ALERT and St. Peter TB Specialized Hospital, Addis Ababa, Ethiopia.

TB drugs	Target gene	Gene mutation pattern (MUT/WT)	Change in amino acid sequences	INH/RIF mono-resistance ()	MDR-RR-TB ()	The pattern of drug resistance	SIT
INH	inhA	—	—	—	—	—
	KatG	^-WT/^+MUT1	S315T1	3 (75%)	3 (100%)	INH-R	SIT498, SIT53, and orphan
		^-WT/^+MUT2	S315T2	1 (25%)	0	INH-R	Orphan
RIF	rpoB	-WT8/MUT3	S531L	0	2 (66.6%)	MDR	SIT149, orphan
		-WT7/MUT1	H526Y	0	1 (33.3%)	MDR	Orphan

^-Gene deletion. ⁺Gene insertion. WT: wild type; MUT: mutation; INH-R: isoniazid resistance; SIT: spoligotype international type.