Table 4.

Rifamycin resistance of M. tuberculosisrecombinant clones

StrainaMutated amino acidbMIC (μg/ml) ofc:
RifampinRifabutinRifapentineKRM-1648
H37RvNone0.25≤0.0150.031≤0.015
H37Rv-pLN-2None0.25≤0.0150.031≤0.015
H37Rv-pLN-sigNone0.25≤0.015≤0.031≤0.015
H37Rv-pAVVal 51632≤0.01516≤0.015
H37Rv-pHTTyr 5266416168
H37Rv-pSLLeu 531>6416>648
H37Rv-Rif-rLeu 531>6416>648
  • a H37Rv, M. tuberculosis H37Rv (ATCC 27294); H37Rv-pLN-2, M. tuberculosis H37Rv clone containing plasmid pLN-2 with wild-type rpoB; H37Rv-pLN-sig,M. tuberculosis H37Rv clone containing pLN-sig with signature nucleotides in rpoB; H37Rv-pAV, M. tuberculosis H37Rv clone containing plasmid pAV with Val 516 mutant allele in rpoB; H37Rv-pHT, M. tuberculosisH37Rv clone containing plasmid pHT with Tyr 526 mutant allele inrpoB; H37Rv-pSL, M. tuberculosis H37Rv clone containing plasmid pSL with Leu 531 mutant allele in rpoB; H37Rv-Rif-r, M. tuberculosis H37Rv (ATCC 35838).

  • b Amino acid numbering corresponds to that of the E. coli RNA polymerase β-subunit.

  • c MICs determined by the BACTEC radiometric method.