Antimicrobial susceptibility of polymerase chain reaction ribotypes of Clostridium difficile commonly isolated from symptomatic hospital patients in the UK.

Two hundred and seventy-one clinical isolates of Clostridium difficile, including the six most common polymerase chain reaction (PCR) ribotypes isolated from symptomatic patients in UK hospitals, were tested against nine antibiotics (imipenem, erythromycin, levofloxacin, piperacillin/tazobactam, ciprofloxacin, co-amoxiclav, cefotaxime, amoxicillin and clindamycin). All 271 strains were susceptible to co-amoxiclav, piperacillin/tazobactam and amoxicillin, and resistant to cefotaxime and ciprofloxacin. Variable degrees of resistance were found to imipenem, erythromycin, levofloxacin and clindamycin. Significantly greater resistance to erythromycin, levofloxacin and imipenem was found in virtually all members of the two most common PCR ribotypes, 001 and 106. Resistance to these agents may have played a part in their selection as the most common strains of C. difficile found in UK hospitals.