Abstract:

Objective To understand the clinical toxin status of clinical isolates of Clostridium difficile in patients with acquired diarrhea in Hohhot and the status of multilocus sequence typing（MLST） of Clostridium difficile. Methods The 326 fecal specimens of adult diarrhea patients in the Affiliated Hospital of Inner Mongolia Medical University were collected from July 2018 to December 2019 for the cultivation and identification of Clostridium difficile. The toxin genes（tcdA and tcdB） and binary toxin genes（cdtA and cdtB） of cultivated Clostridium difficile were amplified by polymerase chain reaction（PCR）to determine producing toxin. The MLST of Clostridium difficile producing toxin was performed. Results Totally,46 isolates of Clostridium difficile were cultivated,of which 35 isolates were Clostridium difficile producing toxin,among them 3 isolates were toxin gene tcdA（-） and tcdB（+） type,and 32 isolates were tcdA（+） and tcdB（+） type. However,binary toxin genes were all negative. The producing toxin isolates came from 13 different ST types（ST2,3,14,33,35,39,42,48,52,54,55,109 and 512）,ST54 was the most common type（22.9%,8/35）,followed by ST2（14.3%,5/35） and ST55（14.3%,5/35）,and no high-yielding isolate of ribosome type 027 （ST1）and high-yielding isolate of ribosome type 078 （ST11）were determined. Conclusions The producing toxin Clostridium difficile with tcdA（+） and tcdB（+） mainly is isolated from adult diarrhea patients in Hohhot,and no high-yielding isolates producing binary toxin are determined. The genotypes of Clostridium difficile are relatively more（13 types）,and ST54,ST2 and ST55 are the top 3 types.

Key words: Clostridium difficile, Toxin type, Multilocus sequence typing