The diagnosis and treatment of Clostridium difficile in antibiotic-associated diarrhea.

Background/aims: This study was initiated to evaluate the role of C. difficile in diarrhea associated with the use of antibiotics, to determine which antibiotics are most often responsible, to characterize the response to several different treatment regimens, and to define the relapse rate as seen in a large teaching hospital in Turkey.

Methodology: Three different patient groups were studied. The first group consisted of 154 individuals with antibiotic-associated diarrhea. The stools of all 154 cases were cultured on cycloserine-cefoxitin-fructose agar (CCFA). If any bacteria grew out, they were identified specifically as C. difficile using a commercially available latex agglutination kit specific for bacterial antigens of C. difficile (MicroScreen C. difficile Latex Slide Test; Merica Diagnostic Limited, Guilford, England). The presence of toxin-A (CDTA) was determined using a MicroScreen CDTA Enzyme Immunoassay kit.

Results: The stools of 31 of these patients grew out enteric pathogens. Twenty-eight of these 31 were CCFA positive. Three different drug regimens (Ornidazole, Ornidazole + Cholestyramine, and Vancomycin) were used to treat these 28 C. difficile positive cases. The second group consisted of 37 hospitalized patients who had been in hospital for more than 30 days without any gastrointestinal symptoms. This group was used to identify the in-hospital carrier rate for C. difficile. Stools from these 37 cases were cultured on CCFA and were analyzed for the presence of CDTA by EIA. Colonization with C. difficile was detected in 4 cases. The third group consisted of 40 healthy subjects who served as a population-based control group. The stools obtained from these 40 cases were cultured on CCFA and analyzed for CDTA as were the stools for the other 2 groups. None were CDTA positive. One case was positive for the presence of non-toxigenic C. difficile.

Conclusions: It can be concluded from these data that, in Turkey, C. difficile is responsible for 20% of antibiotic-associated diarrheas. Lincomycin, Azithromycin and Ampicillin were most often associated with the development of antibiotic-associated diarrhea. Ornidazole and Vancomycin were effective agents for C. difficile-associated diarrhea with the latter agent being associated with no relapses.