[Ciprofloxacin, clarithromycin, rifampin: in vitro bactericidal activity of double and triple drug combinations against strains of atypical mycobacteria].

Bactericidal activity of ciprofloxacin (CIP), clarithromycin (CLA), rifampin (RIF) alone and in combinations was studied against five atypical mycobacteria (4 isolates from patients with Acquired Immunodeficiency Syndrome and 1 collection strain) by time killing curves method. Drugs were used at their attainable serum levels: CIP (1 microgram/ml), CLA (2 micrograms/ml), RIF (16 micrograms/ml). The decrease in CFU in comparison to inoculum (10(6)-10(7) CFU/ml) was evaluated by viable counts after 1, 2, 3, 4 and 5 days of incubation at 35-37 degrees C. Drug combinations enhanced slightly the killing of drugs alone. CIP+CLA was the most effective against MAC strains whereas CIP+RIF appeared as the best combination against rapidly growing species except M. phlei which was the most resistant strain.