Intracellular Antimycobacterial Activity of Ciprofloxacin and Ofloxacin in Mycobacterium Fortuitum Infected Human Polymorphonuclear Leucocytes

Abstract

The broadspectrum quinolone antibiotics ciprofloxacin and ofloxacin were tested for activity against the atypical mycobacterium M.fortuitum. In vitro minimal inhibitory concentrations (MIC) were done in Brain Heart Infusion broth and intracellular determinations in Medium 199 cell culture medium. The PMNs with intracellular bacteria and controls with or without drugs were incubated for six hours at 37°C. Hourly, 0.1 ml aliquotes were taken for colony forming units (cfu) assays. In vitro and intracellular MIC's for ciprofloxacin were 0.125mg/l and 0.625 mg/l respectively, while for ofloxacin they were 0.2mg/l and 0.4 mg/l, respectively.