Table 2.

MICs (agar dilution) of rifampin and rifabutin forH. pylori with wild-type rpoB sequence (DR62a and 2802A) and for H. pylori harboring a novel mutation, V149F (DR62n and 2802A-R)a

StrainCodon no. (V149/V176) and amino acidMIC (μg/ml)
RifampinRifabutin
H. pylori
 DR62a0.250.002
 DR62nV149F168
 2802A0.250.008
 2802A-RV149F1616
M. tuberculosisb
 6910.03
 7120.5
 7241
 75V176F81
 83V176F322
 84V176F322
  • a The equivalent mutation (V176F) was seen for three of six M. tuberculosis samples with the rifampin resistance phenotype but the wild-type cluster region.

  • b M. tuberculosis strain designations are from the work of Yang et al. (17). The data for M. tuberculosis come from 6 samples out of 100 of a collection ofM. tuberculosis isolates for which MICs of rifamycin are elevated.