RECOMBINANT MYCOBACTERIUM-AURUM EXPRESSING ESCHERICHIA-COLI BETA-GALACTOSIDASE IN HIGH-THROUGHPUT SCREENING OF ANTITUBERCULOSIS DRUGS

Mycobacterium aurum is considered a surrogate of M. tuberculosis and r ecently has been proposed as test organism in high throughput screenin g of antituberculosis drugs (3). In this investigation, we suggest use of a recombinant M. aurum expressing E. coli lacZ gene, in which beta -galactosidase production is the reporter system as recently reported by us (6). The assay is based on production of beta-galactosidase in p resence of drugs during growth, Enzyme production was inhibited within 4 h by frontline antimycobacterial drugs like streptomycin, rifampici n, isoniazid, ethambutol, ofloxacin, and sparfloxacin at their MICs. T he assay could be performed conveniently in 96-well microtiter plate f ormat. (C) 1997 Academic Press.