S. WongwanichP. PongpechC. DhiraputraS. HuttayananontP. SawanpanyalertNational Institutes of Health, BethesdaChulalongkorn UniversityMahidol University2018-09-072018-09-072001-01-01Clinical Microbiology and Infection. Vol.7, No.8 (2001), 438-4411198743X2-s2.0-0035436320https://repository.li.mahidol.ac.th/handle/20.500.14594/26881Objectives. To characterise genotypes of Clostridium difficile strains isolated from asymptomatic individuals and patients with diarrhea. Methods. Fecal specimens from 235 asymptomatic infants <12 months, 76 asymptomatic children 1-11 years and 132 adult patients with antibiotic-associated and non-antibiotic-associated diarrhea obtained from Siriraj Hospital, Bangkok from October 1998 to April 1999 were examined for C. difficile by cycloserine-cefoxitin-fructose agar culture. The presence of the C. difficile toxin A gene was determined by specific PCR with the use of primers 5-(CCC AAT AGA AGA TTC AAT ATT AAG CTT)- 3 and 5-(GGA AGA AAA GAA CTT CTG GCT CAC TCA GGT)-3. All C. difficile isolates were subsequently genotyped by pulsed-field gel electrophoresis (PFGE). Results. The C. difficile strains were found in 28 (11.9%) asymptomatic infants, 16 (21.1%) asymptomatic children and 33 (25%) adult patients. In total, 14 PFGE types and eight subtypes designated as types A, B, C, D, E, F, G, H, I, K, L, M and N, and A1, A2, A3, A4, B1, B2, B3 and E1, respectively, were identified. Only two isolates from infants and 18 isolates from adult patients were toxin A gene positive by PCR. Both isolates of toxigenic C. difficile were from infants in the same ward and were PFGE type B. PFGE type A was the predominant type among all toxigenic isolates (12 of 18 isolates) from adult patients. The other PFGE types of toxigenic C. difficile found in adult patients were: type A1, one isolate; type B, four isolates; and type C, one isolate. Types B2 and D were identified in 38.5% and 46.2%, respectively, of the toxin A gene-negative isolates of C. difficile from infants. Conclusions. These results revealed the occurrence of three distinct clusters from different wards in Siriraj Hospital. The toxigenic C. difficile of PFGE type A and related subtypes was a predominant infective clone in adult patients, whereas non-toxigenic C. difficile types B2 and D were encountered in asymptornatic infants. This information can be useful in epidemiologic investigations.Mahidol UniversityMedicineArticleSCOPUS10.1046/j.1198-743X.2001.00308.x