<i>In Vitro</i> Activities of MCB3681 and Eight Comparators against Clostridium difficile Isolates with Known Ribotypes and Diverse Geographical Spread

Abstract

Treatments for <i>Clostridium difficile</i> infection remain limited, despite the introduction of fidaxomicin, and development of new agents is necessary. We determined the <i>in vitro</i> susceptibilities of 199 prevalent or emerging <i>Clostridium difficile</i> PCR ribotypes to MCB3681, a novel investigational quinolonyl-oxazolidinone, and 8 comparators (metronidazole, vancomycin, fidaxomicin, moxifloxacin, ciprofloxacin, clindamycin, tigecycline, and linezolid). MCB3681 showed good activity against <i>C. difficile</i> with no evidence of MCB3681 resistance in isolates showing either moxifloxacin or linezolid resistance or both moxifloxacin and linezolid resistance.