Antimicrobial susceptibility of Clostridium difficile by E test.

The in vitro inhibitory activity of 11 antimicrobials against 44 clinical isolates of Clostridium difficile was investigated. Minimum inhibitory concentrations (MICs) were determined using E test. Metronidazole (MIC90 0.38 microg/mL), teicoplanin (MIC90 0.75 microg/mL) and vancomycin (MIC90 1.0 microg/mL) were very active against the isolates examined, whereas, resistance to imipenem, cefoxitin, clindamycin and ciprofloxacin was found in most of the tested strains. We concluded that teicoplanin warrants clinical trials to determine its adequate dosage to treat C. difficile infection. The commonly used regimens to treat intra-abdominal and/or anaerobic infections (eg. imipenem, cefoxitin, clindamycin or ciprofloxacin) need special attention, while considering the side effects of C. difficile-associated diarrhea.