Colorimetric phage-based assay for detection of rifampin-resistant Mycobacterium tuberculosis.

Tests based on bacteriophage replication enable rapid screening of Mycobacterium tuberculosis for drug resistance. We describe a novel broth-based colorimetric method for detecting phage replication. When clinical isolates were tested by this novel method, high concordance was observed with both the traditional phage assay and gene mutation analysis for detection of resistance to rifampin.