Frequency and antibiotic resistance profile of Clostridioides difficile among cancer patients in an adult hematology-oncology unit: Contributing factors and Follow up.

Cancer patients are particularly at risk of Clostridioides (Clostridium) difficile (C. difficile) infection as a considerable healthcare burden and common cause of nosocomial diarrhea. This study aimed to investigate the risk factors and microbiological follow-up of C. difficile among hospitalized hematology-oncology patients in the central part of Iran. Of 1100 patients who were diagnosed with cancer receiving radiotherapy and/or chemotherapy,70 patients with clinical signs of gastrointestinal complications were entered in the study. The Glutamate Dehydrogenase test kit was used for the first detection of the bacteria. The faecal specimens were cultured in Cefoxitin-Cycloserine-fructose agar in anaerobic conditions. PCR was conducted for the precise detection of C. difficile and toxin by evaluation of the presence of tpi, cdd, and tcdA/B genes by PCR. The antimicrobial susceptibility testing of all the isolates was performed. The fecal samples were analyzed for resistant Escherichia coli, which may indicate co-infections in the patients. C. difficile was isolated from 16 (22.8 %) cases. Thirteen (81.2 %) patients with diarrhea compared with 3(18.8 %) patients without diarrhea were positive for C. difficile (P < 0.001). PCR confirmed all bacteria as toxigenic and possessed genes encoding for toxins A and/or B. Of 16 isolates, six isolated (37.5 %) and two isolates (12.5 %) were resistante to vancomycin, and metronidazole, respectively. Notably, 8 (50 %) cases harbored E. coli, and six isolates (75 %) were ESBL-positive. Results showed that C. difficile can cause gastrointestinal complaints in cancer patients in our study. We underscore the necessity for early diagnosis of this pathogen in oncology patients.