Activity of a Novel Cyclic Lipopeptide, CB-183,315, against Resistant Clostridium difficile and Other Gram-Positive Aerobic and Anaerobic Intestinal Pathogens

We evaluated the activity of CB-183,315 against Clostridium difficile, including strains that are resistant to fluoroquinolones and metronidazole and with elevated MICs to vancomycin as well as other Gram-positive intestinal pathogens. The MICs of CB-183,315 against all C. difficile isolates were <= 1 mu g/ml. CB-183,315 had greater activity than vancomycin and metronidazole against C. difficile isolates and was more active than the comparators against vancomycin-resistant enterococcus (VRE). CB-183,315 also had excellent activity against methicillin-resistant Staphylococcus aureus (MRSA), other Clostridium spp., and Peptostreptococcus spp.