The etiology, molecular epidemiology and clinical characteristics of Clostridium difficile infections in Xiangya Hospital

Abstract

Objective A preliminary study on the etiology, the gene typing, the PCR-ribotyping and the clinical features of Clostridium difficile from clinical isolates at Xiangya Hospital could improve the isolation rate and provide the basis for effectively prevention of C.difficile. Methods A prospective observational study was performed.A total of 452 stool samples were collected during June to December 2012 at Xiangya Hospital.All stools were anaerobic cultured by selective medium and identified by API 20A for C.difficile.The positive isolates were detected the toxin genes（tcdA, tcdB, cdtA, cdtB）and ribotyping (16S-23S internal spacer region) by PCR.The clinical data of all patients were collected and analyzed through Logistic regression to discover the risk factors for the development of C.difficile infection（CDI）. Results The rate of CDI occurrence was 13.94%(63/452), among them, 42.86%(36/63) were A-B+ strains and only 14.29%(9/63) were obtained from community acquired-CDI.No binary toxin was detected in any of the isolates.Eleven different PCR ribotypes were identified, the dominant ribotype CD017 accounted for 22.22%（14/63）.Logistic regression analysis showed that the risk factors for CDI included age >55（P=0.016; OR=4.45; 95%CI: 1.33-14.91）, diarrhea frequency（P=0.007, OR=0.03; 95%CI: 0.002-0.38） and the duration of diarrhea（P=0.015; OR=7.86; 95%CI: 1.50-41.16）. Conclusions C.difficile is the main pathogens of diarrhea patients and is mainly from hospital infections with higher detection rate of A-B+ in Xiangya Hospital.Ribotyping exist comparative advantages type CD017.No evidence suggests outbreak of C.difficile infection.（Chin J Lab Med,2014,37: 855-860） Key words: Diarrhea; Clostridium difficile; Bacterial toxins; Ribotyping; Epidemiology, molecular