The effects of rifampicin and fluoroquinolones on tubercle bacilli within human macrophages

The objective of this study was to determine the activities of rifampicin, ciprofloxacin and sparfloxacin against M. tuberculosis H37Rv in human macrophages. The minimal inhibitory concentrations (MIC) were determined by agar macrodilution and broth microdilution methods and were 0.5, 1 and 0.125mg/l, respectively. Concentrations of rifampicin at 0.5 and 2.5µg (P<0.001), ciprofloxacin at 4 and 8µg (P<0.001) and sparfloxacin at 0.125µg (P<0.05), 0.625µg (P<0.001) and 1.25µg (P<0.001) were found to be effective against intracellular bacteria. Ciprofloxacin and especially sparfloxacin were effective in macrophages and may be useful in the treatment of tuberculosis particularly infections caused by multiply drug resistant strains. © 2003 Published by Elsevier B.V. and the International Society of Chemotherapy.