Correlation of multidrug resistance, toxinotypes and PCR ribotypes in Clostridium difficile isolates from Kuwait

Clostridium difficile is a common cause of nosocomial diarrhea. its role in community-acquired diarrhea is also becoming an important public health concern. Hardly any studies have correlated strain ribotypes, toxinotypes and multidrug resistant (MDR) profiles. To investigate these characteristics, 65 C. difficile isolates obtained from stool samples of patients whose cultures were negative on admission but became positive after 48 h of admission to the ICUs of our hospitals were studied to determine the prevalent ribotypes, toxinotypes and their relationship with the MDR profiles using ELISA/cytotoxicity assays, PCR and Etest methods. The toxin-producing strains were toxinotyped by the PCR-RFLP technique. Of the 65 isolates, 42 (64.6%) were toxigenic (T). The isolates were of diverse ribotypes but types 097, 078, 056 and 039 (NT) were predominant. thirty (71.4%) of 42 T and 13 (56.5%) of 23 NT strains were multiresistant to 3 or more antibiotics. Only 3 toxinotypes (0, "V-like" and XII) were encountered. Of the 42 t strains, 30 (71.4%) were of toxinotype 0, and 12 belonged to variant toxinotypes: 4 (9.4%) to toxinotype XII and 8 (19%) to "V-like" toxinotype in which amplified B1 PCR fragments was amplified as expected for toxinotype V but the A3 PCR fragment could not be amplified. The 43 mDR strains were assigned to 3 arbitrary resistance groups; groups 1, 11 and III. the most prevalent isolates (37; 86.1%) were in group II. Of the predominant T ribotypes (097, 078 and 056), c. 62% clustered in group II. Although the number of strains toxinotyped was small, ribotyping and toxinotyping correlated well with the published literature, except for 078 with a novel "V-like" toxinotype. Antibiogram was not as clear-cut.