Ribotype distribution of Clostridioides difficile isolated from patients with diarrhea in Ahvaz, Iran.

Diarrhea is one of the leading infectious diseases, causing the greatest health burden in most developing countries, with Clostridioides difficile-associated diarrhea being the primary cause of hospital-acquired diarrhea. Given the demonstrated mortality associated with diarrhea and its consequences and the significant association between C. difficile and diarrhea, this study aimed to investigate the ribotype distribution of C. difficile isolated from patients with diarrhea in Ahvaz, Iran. From May to November of 2025, 50 patients with diarrhea were admitted to the hospital. The tpi gene was amplified by the PCR method to detect C. difficile isolates. The other method was a real-time PCR to identify C. difficile isolates from stool samples. The two diagnostic methods applied in this study were comparable. PCR was used to investigate the presence of C. difficile toxin genes. Among the 12 positive isolates, the tcdA gene was detected in 6/12 (50%) of the isolates. Additionally, 6/12 (50%) of the isolates was detected the tcdB gene. 1/12 C. difficile isolate was resistant to vancomycin, but all isolates were susceptible to metronidazole and fidaxomicin. Ribotype 001 was the most dominant (n = 4, 33.3%), with ribotype 126 representing the second most common at 25% (n = 3). Ribotype 070 (n = 2, 16.7%), 084 (n = 2, 16.7%), and 078 (n = 1, 8.3%) were detected at lower frequencies. The detection of toxin-producing genes in some isolates is also an indication of the bacterium's significant virulence potential. The findings indicated the need for ongoing surveillance of C. difficile and the antibiotic resistance characteristics in hospital settings.