Background & Objectives: Clostridium difficile as an etiologic agent of pseudomembraneous colitis and major cause of nosocomial antibiotic-associated diarrhoea is typed by phenotypic and molecular methods. The aim of this study was to investigate the distribution of ribotypes of the organism in the given region and time.

  Methods: In this study 18 strains isolated from patients from different hospital wards of Poland in 2002 and 2003, were examined and identified by susceptibility to vancomycin and metronidazole. The samples were re-identified using UV and latex agglutination to ensure the existence of A and B toxins. DNA was extracted and after amplification by PCR and electrophoresis, the strains were ribotyped.

  Results : The findings showed that all the strains were susceptible to vancomycin and metronidazole and all the colonies showed greenish-yellow fluorescence under UV. Moreover, all the strains were positive in terms of latex agglutination. Seven strains were toxin A positive and all were toxin B positive except one strain. In molecular ribotyping it was found out that these strains belonged to seven ribotypes, namely 12, 14, 17, 18, 29, 70 and 90 most of which were ribotype 17 (61%).

  Conclusion: Our observations imply that in each area a particular ribotype of c.difficile is of higher prevalence and ribotyping of this clostridium is necessary for epidemiologic studies. Identification and PCR-ribotyping of common strains of this organism in Iran are recommended for epidemiologic follow-ups.