In vitro susceptibility of genotypically distinct and clonal Clostridium difficile strains to oritavancin

Clostridium difficile infection is a nosocomial disease of increasing importance. First-line treatment is limited to metronidazole or vancomycin. Oritavancin is a lipoglycopeptide with activity against Gram-positive bacteria, including drug-resistant pathogens. MICs of oritavancin, metronidazole and vancomycin for genotypically distinct C. difficile strains, including epidemic C. difficile PCR ribotypes 001 and 027, were determined by agar incorporation and broth macrodilution methods. In agar incorporation methods, the impact of supplements on oritavancin MICs was tested to address oritavancin binding to surfaces.