Activity of OPT-80, a novel macrocycle, compared with those of eight other agents against selected anaerobic species

Agar dilution MIC was used to compare activities of OPT-80, linezolid, vancomycin, teicoplanin, quinupristin/dalfopristin, amoxicillin/clavulanate, imipenem, clindamycin, and metronidazole against 350 gram-positive and -negative anaerobes. OPT-80 was active against gram-positive strains only, especially Clostridium spp. (85 strains tested, including 21 strains of C difficile), with MICs ranging between less than or equal to 0.016 and 0.25 mug/ml.