Coexistence of Clostridioides difficile and Staphylococcus aureus in gut of Iranian outpatients with underlying inflammatory bowel disease.

Clostridioides difficile and Staphylococcus aureus are two well-known pathogens both causing hospital- and community-acquired infections. However, their intestinal coexistence was not well investigated in inflammatory bowel disease (IBD). Herein, we explored the prevalence of C. difficile, S. aureus and their coexistence in the gut of Iranian patients with IBD. Fecal and colon specimens were obtained from 70 outpatients with underlying IBD, and investigated for the presence of C. difficile and S. aureus. C. difficile isolates were characterised by CE-ribotyping. PCR was used for detection of toxin-encoding genes of C. difficile and S. aureus isolates. The antimicrobial susceptibility testing of C. difficile and S. aureus isolates were examined by agar dilution and Kirby-Bauer disk diffusion methods, respectively. Totally, C. difficile and S. aureus were detected in only 5.7% and 15.8% of IBD flares. Coexistence of C. difficile and S. aureus was detected in 5.7% of IBD flares. Two different C. difficile ribotypes including RT 126 and RT 017 were identified showing toxin profiles of tcdAB/cdtAB and tcdAB, respectively. In S. aureus isolates, only positivity for the presence of sea enterotoxin was detected. C. difficile isolates were susceptible to metronidazole, ceftazidime and fidaxomicin. The highest resistance of S. aureus isolates was observed against penicillin (92.3%), following amoxicillin-clavulanate (38.5%) and amikacin (30.8%). Our findings demonstrated that patients with IBD flare are more sensitive to acquire coinfection of C. difficile and S. aureus than remission. However, more robust data is required to study the crosstalk between these enteric infections and their clinical relevance in patients with IBD flare.