BIOLUMINESCENCE SCREENING IN-VITRO (BIO-SIV) ASSAYS FOR HIGH-VOLUME ANTIMYCOBACTERIAL DRUG DISCOVERY

Bioluminescence-based assays to indicate antimicrobial susceptibility have been developed and validated for recombinant strains of Mycobacte rium tuberculosis, Mycobacterium bovis BCG, Mycobacterium avium, and M ycobacterium intracellulare expressing an integrated eukaryotic lucife rase gene. MICs determined with these bioluminescence assays for sever al antimycobacterial agents, including isoniazid, ethambutol, rifampin , amikacin, streptomycin, ciprofloxacin, and clarithromycin, compared favorably with traditional BACTEC methods and visual estimations of th e inhibitory end point, Assay methodology has been optimized for the a nalysis of large numbers of novel compounds and is simple, inexpensive , and labor efficient, The availability of these four recombinant myco bacteria has permitted a strategy for drug discovery employing the non pathogenic BCG strain for mass screening purposes with subsequent conf irmation of activity against the pathogenic mycobacteria, Furthermore, evidence suggests that the BCG-based screen may allow the direct iden tification of bactericidal agents.