Antibiotic susceptibility of clostridium difficile isolates from adult patients at two Jamaican hospitals. Clinical and epidemiological implications

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 demonstrates a significant association with diarrhoea (60.9 percent, 14/23, p<0.001). These strains were predominantly found at the University Hospital of the West Indies (UHWI, 94.1 percent, 16/17). Strains resistant to erythromycin and clindamycin together were commonly found at the National Chest Hospital (NCH, 68.2 percent, 15/22). All erythromycin sensitive strains found at the NCH were from patients transfered to that hospital. These findings suggest that there is a common strain of C difficile (erythrmycin 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 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 suppression of the normal microflora by antibiotics and colonic over growth with C difficile. (AU)

Antibiotic susceptibility of 39 Clostridium difficile isolates from adult patients at the University Hospital of the West Indies (UHWI) and the National Chest Hospital (NCH)

The antibiotic susceptibility to six antibiotics of 39 C. difficile isolates (38 toxigenic) from stool specimens (14 adult diarrhoeal and 25 adult nondiarrhoeal) was determined by disc diffusion. Susceptibility to clindamycin (CC), cotrimoxazole (SXT), erythromycin (E), vancomycin (VA), tetracycline (TE) and chloramphenicol (C) was correlated with diarrhoeal and nondiarrhoeal cases. With the exception of VA, a wide variation in susceptibility was noted with CC, E, SXT, TE, and C, with a strong correlation between E sensitive isolates in diarrhoeal cases (69.8 percent). Compartively and of equal significance were erythromycin resistant isolates, primarily form NCH (93.8 percent). All erthromycin resistant isolates were simultaneously resistant to clindamycin (no zone) with only one isolate associated with a diarrhoeal case from UHWI. A review of patients' dockets revealed that actual transferrals to hospitals were largely responsible for the differences in erythromycin susceptibility among isolates.(AU)