o Azizi - Master of medical microbiology, Pasteur institute of Iran, Tehran, Iran
M.M Aslani - Professor, Department of Microbiology, Pasteur institute of Iran, Tehran, Iran
M Azimi rad - Bachelor of laboratory science, Research Center of Gastroenterology and Liver Disease, Shahid Beheshti University of Medical Sciences, Tehran, Iran
M Aleboyeh - Assistant Professor of Microbiology, Research Center of Gastroenterology and Liver Disease, Shahid Beheshti University of Medical Sciences, Tehran, Iran
S.F Mosavi - Assistant Professor, Department of Microbiology, Pasteur institute of Iran, Tehran, Iran
M.R Zali - Professor, Research Center of Gastroenterology and Liver Disease, Shahid Beheshti University of Medical Sciences, Tehran, Iran

Background & Aims: Clostridium difficile has been identified as a pathogen in antibiotic associated diarrhea (AAD), pseudomembranous colitis and also nosocomial diarrhea. The present study was performed to find the prevalence of toxigenic strains of C .difficile isolated from diarrhea patients hospitalized in Tehran hospitals. Method: A total of ۹۸ fecal samples obtained during July to December ۲۰۱۰ were studied. Samples were rapidly cultured on the CCFA medium and incubated at the anaerobic conditions. Then ELISA was done to detect toxin A and B in the stool. Molecular identification of C.difficile was done by cdd۳ universal primer and toxin A gene (tcdA), toxin B gene (tcdB) and binary toxin profiles were determined by PCR method. Results: from a total of ۹۸ fecal samples, ۱۵ samples (۱۵.۳%) were positive of which, ۱۲ strains (۲۱.۲%) were A+B+, ۲ strains (۲%) were A+B-, and ۱ strain (۱%) was A-B+. Conclusion: This study showed that Clostridium difficile is an important pathogen in the development of nosocomial diarrhea. Therefore, routine detection of C.difficile in suspected cases is recommended.

clostridium difficile, C. difficile enterotoxin A, C. difficile enterotoxin B, Diarrhea