In vitro activities of daptomycin, ciprofloxacin, and other antimicrobial agents against the cells and spores of clinical isolates of Bacillus species

Daptomycin inhibited 67 of 70 clinical isolates of Bacillus species at <= 1 mu g/ml and 100% of them at <= 2 mu g/ml. It showed bactericidal activity similar to that of ciprofloxacin against vegetative cells but not against spores. For 2 strains, the ciprofloxacin MICs were > 4 g/ml, and 10 strains were resistant to erythromycin.