Clostridium difficile infections in a Shanghai hospital: antimicrobial resistance, toxin profiles and ribotypes

The incidence of Clostridium difficile infection (CDI) has risen markedly since 2003, however data from China are limited. A 1-year study was conducted at the University Hospital Huashan to characterise clinical isolates of C. difficile. Of 74 isolates, 56 were from the first episode of CDI (43 A(+)B(+) and 13 A(-)B(+)), 5 were from recurrences and 13 were toxin-negative. No binary toxin or TcdC deletion was detected. All strains were susceptible to metronidazole, vancomycin, meropenem and piperacillin/tazobactam. Resistance to moxifloxacin, ciprofloxacin, levofloxacin, erythromycin, clindamycin, tetracycline, rifampicin and fusidic acid was found in 46.4%, 100%, 60.7%, 71.4%, 71.4%, 35.7%, 25.0% and 17.9% of the isolates, respectively. All moxifloxacin-resistant isolates carried a mutation in either gyrA, gyrB or both. Fourteen different polymerase chain reaction ribotypes were identified, with a specific clone (SH II) accounting for 25% of isolates. No isolates belonged to ribotype 027. The present study is the first systematic survey of clinical C. difficile isolates in China. Further surveillance is required to detect clustering of cases and to monitor the emergence of specific highly virulent clones and resistance.