RNA polymerase inhibitors with activity against rifampin-resistant mutantsof Staphylococcus aureus

A collection of rifampin-resistant mutants of Staphylococcus aureus with ch aracterized RNA polymerase beta -subunit (rpoB) gene mutations was cross-sc reened against a number of other RNA polymerase inhibitors to correlate sus ceptibility with specific rpoB genotypes. The rpoB mutants were cross-resis tant to streptolydigin and sorangicin A. In contrast, thiolutin, holomycin, corallopyronin A, and ripostatin A retained activity against the rpoB muta nts. The second group of inhibitors may be of interest as drug development candidates.