Diagnosis of Clostridium difficile antibiotic associated diarrhoea culture versus toxin assay

To compare the results of Clostridium Difficile (CD) on culture with detection of C. difficile toxin by Enzyme Immunoassay (EIA) in the stool specimens of hospitalized patients with antibiotic associated diarrhoea (AAD).

The study included 80 adult patients with AAD and 20 adult patients with non-AAD. Stool specimens of all these subjects were inoculated on cycloserine cefoxitin fructose agar and incubated anaerobically to isolate C. difficile. At the same time, all the stool specimens were tested for C. difficile toxin by EIA technique using cytoclone A and B kit manufactured by Cambridge Biotech Corporation, Worcester, Massachusette.

Out of 80 adult patients with AAD, thirty were females and fifty males. C. difficile was isolated on culture from stool specimen of 16 patients, while twenty-three stool specimens were positive for C. difficile toxin. From 20 control subjects, C. difficile was isolated from stool specimen of only one subject. No stool specimen from the controls was positive for toxin.

Diagnosis of CDAAD by culture is difficult and time consuming because of strict anaerobic nature of organism. Moreover, mere isolation of C. difficile on culture is not sufficient to establish the pathogenic role of these isolates. C. difficile toxin detection by EIA technique is a highly sensitive and specific method for diagnosis of CDAAD. Using this method, results are available in three hours time. Therefore, EIA is recommended for rapid diagnosis of CDAAD.