Table 2.

Rifamycin MICs for clinical isolates of M. tuberculosis with mutant rpoB alleles

Clinical isolateAffected amino acid(s) (change)bMIC (μg/ml) ofa:
Rifam- pinRifa- butinRifa- pentineKRM1648
Resistantc
 TB54511 (Leu→Pro)20.51<0.01
 TB022513 (Gln→Pro)328.0320.32
 TB872513 (Gln→Pro)324.0320.32
 TB713513 (Gln→Leu)162.0160.16
 TBU36514 (Phe insertion)32<2.032<0.16
 TB3908516 (Asp→Val)32<0.5320.01
 TBYE-67516 (Asp→Val)320.5320.01
 TBGro-1516 (Asp→Tyr)2<0.580.04
 TB33517 (Gln deletion)328.0642.56
 TB4183518 (Asn deletion)6464>325.12
 TB053518–519 (Asn deletion)>64>32>32>10.24
 TBRos-1519 (Asn→Lys)320.5320.01
 TB3505521 (Leu→Met)328.0322.56
 TBNor-1522 (Ser→Leu)320.5320.01
 TB2230522 (Ser→Leu),  516 (Asp→Val)>32>1.0320.12
 TBRR-1526 (His→Arg)6464<325.12
 TB5095526 (His→Leu)168160.56
 TBRR-7526 (His→Pro)>6432>642.56
 TB160526 (His→Pro)>64>32>645.12
 TBYE-68526 (His→Tyr)>6432>64>2.56
 TB3081526 (His→Tyr)>64>32>645.12
 TB052526 (His→Asp)>6464>32>2.56
 TB3140526 (His→Asp)>6464>325.12
 TB91526 (His→Asp),  509 (Ser→Leu)>648>640.64
 TB023527 (Lys→Gln)>3216322.56
 TBYE-14531 (Ser→Leu)>6432>6410.24
 TB3241531 (Ser→Leu)>6432>64>10.24
 TB019531 (Ser→Phe)6432>6410.24
 TB3126533 (Leu→Pro)648642.56
Susceptible
 TBSmi-1None0.5<0.5<0.12<0.01
 TBH1-7None0.5<0.50.12<0.01
  • a MICs determined by the BACTEC radiometric method.

  • b Amino acid numbers correspond to the E. coli numbering system for the RNA polymerase β-subunit.

  • c Clinical isolates of M. tuberculosis resistant to rifampin at ≥2 μg/ml by the BACTEC radiometric method or at 1 μg/ml by conventional agar plate testing.