Table 2.

CFU-based MIC₉₀ of ETH in BCG and M. tuberculosis parental and mutant strains.

	Parental strain	ethA/R KO	ethA/R KO complement ethA/R	pMV262-ethR	pMV306-ethR	ethA KO
BCG	10–20	NA	10–20	ND	ND	ND
CDC1551	2.5–5	40	2.5–5	20–40	ND	20–40
Erdman	1.25–2.5	2.5–5	1.25–2.5	1.25–2.5	2.5–5	1.25–2.5
H37Rv	1.25–2.5	2.5–5	1.25–2.5	2.5–5	ND	2.5–5

Bacterial suspensions corresponding to 1x, 2x, and 4x MIC₅₀ were plated onto 7H11 agar plates. CFU were enumerated after 16 days incubation at 37°C and the CFU-based MIC₉₀ range (in μM) was determined. pMV262-ethR was introduced into WT MTB strains. pMV306-ethR was introduced into ethA/R KO Erdman strain.

ND, not determined; DF, drug-free; NA, not available due to complete resistance to the drug.