TABLE 1.

Hygromycin B resistance mutations, MICs, and growth rates

Strain	MIC		Relative resistancea	Generation time (h)
	μg/ml	μM
Wild type
M. smegmatis SMR5	16	0.03		3.4 ± 0.4
M. smegmatis rrnB−	16	0.03		3.2 ± 0.5
Mutants
U1406C	1,024	1.9	64	5.3 ± 0.8
C1496U	512	0.97	32	5.2 ± 1.1
U1498C	128-256	0.24-0.48	8-16	3.8 ± 0.3
Recombinants
pMV361ΔKan-Gm-rRNA1406C	1,024	1.9	64	ND
pMV361ΔKan-Gm-rRNA1496U	512	0.97	32	ND
pMV361ΔKan-Gm-rRNA1498C	128-256	0.24-0.48	8-16	ND

^aRelative resistance is the MIC of mutant cells divided by the MIC of wild-type cells.

^bND, not done.