Bioluminescent Mycobacterium aurum expressing firefly luciferase for rapidand high throughput screening of antimycobacterial drugs in vitro and in infected macrophages

The slow growth and highly infectious nature of Mycobacterium tuberculosis is a limiting factor in its use as test organism in high throughput screeni ng for inhibitory compounds. To overcome these problems, use of surrogate s trains and reporter genes have been considered. In this study, we have inve stigated the application of a fast growing nonpathogenic M. aurum expressin g firefly luciferase in rapid screening of antituberculosis compounds in vi tro and in infected macrophages using bioluminescence assay. The assay is b ased on luminescence determination using luciferin as substrate. Inhibition of bioluminescence was obtained with frontline antimycobacterial drugs lik e streptomycin, rifampicin, isoniazid, ethambutol, ofloxacin, and sparfloxa cin at their reported MICs. Inhibition could be observed as early as 2 h in vitro and within 24 h in infected macrophages. The system can reliably be used in high throughput screening. (C) 2000 Academic Press.