RESUMO
The susceptibility of 39 toxin producing Clostridium difficile isolates from stools of hospitalized patients was determined, by disc diffusion, to six antibiotics. All but one isolate (toxin A negative) produced toxin A and toxin B. A wide variation in susceptibility to clindamycin, tetracycline and chloramphenicol was noted. Erythromycin and cotrimoxazole showed a clear-cut discrimination in resistance and susceptibility, while all isolates were sensitive to vancomycin. Erythromycin sensitive isolates demonstrated a significant association with diarrhoea (60.9, 14/23, p < 0.001). These strains were predominantly found at the University Hospital of the West Indies (UHWI, 94.1, 16/17). Strains resistant to erythromycin and clindamycin together were commonly found at the National Chest Hospital (NCH, 68.2, 15/22). All erythromycin sensitive strains found at the NCH were from patients transferred to that hospital. These findings suggest that there is a common strain of C difficile (erythromycin resistant) at the NCH different from that found at the UHWI; the resistant pattern seen with isolates from the NCH was typical of toxigenic serogroup C strain and could be typed by the the disc diffusion method. Patients at the NCH who were colonized with either of the two strains of C difficile were likely to get diarrhoea, once there was suppression of the normal microflora by antibiotics and colonic overgrowth with C difficile.