Table 2. Development of Rif-resistance in wild type Mtb H37Rv but not in Δ-tgs1 mutant upon application of multiple-stress; complementation restores Rif-resistance.

Mtb strains	Days under Multiple-stress	Resistance to Antibiotics (%)
		INH (0.8 µg/ml)	Rif (5.0 µg/ml)
WT-H37Rv	0	0.03 (±0.01)	0.04 (±0.02)
	9	34.7 (±12)	4.7 (±1.9)
	18	84.4 (±17.5)	12.5 (±3.4)
Δ-tgs1	0	0.01 (±0.01)	0.03 (±0.02)
	9	21.1 (±7.8)	1.2 (±0.9)
	18	31.2 (±13.1)	1.9 (±0.9)
C-Δ-tgs1	0	0.04 (±0.02)	0.03 (±0.01)
	9	37.9 (±13.5)	5.2 (±2.1)
	18	91.0 (±19)	11.0 (±4.5)

Mtb cultures at 0, 9 or 18 days of multiple-stress were treated with Rif (5 µg/ml) or INH (0.8 µg/ml) for 5 days. Viable bacilli were enumerated by the cfu count method and compared with controls not subjected to antibiotic treatment. WT-H37RV, Mtb H37RV, Δ-tgs1, tgs1 deletion mutant of WT-H37Rv, C-Δ-tgs1, complemented tgs1 mutant. Rif, Rifampicin; INH, Isoniazid.