Evaluation of three enzyme immunoassays and toxigenic culture for diagnosis of Clostridium difficile-associated enteritis in piglets

The aim of this study was to compare test performances of three commercial enzyme immunoassays (EIAs) for A and B toxin detection and that of a simple toxigenic culture protocol to the cytotoxicity assay (CTA) as the gold standard for diagnosis of Clostridium difficile-associated enteritis in piglets. A total of 73 piglets submitted to the Veterinary School of Universidade Federal de Minas Gerais were included in this study. Intestinal content was collected from 62 diarrheic and 11 non-diarrheic piglets, 1 to 7 days old. Vero cells were used in the CTA protocol to detect A and B toxins. Fecal samples were inoculated on cycloserine-cefoxitin fructose agar for isolation of C difficile. The EIAs were performed according to the manufacturers’ instructions. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for each EIA and for toxigenic culture against CTA. The CTA was positive for 22 of the 73 samples (30.1%). Sensitivities of all EIAs and toxigenic culture for the piglet samples were low (41% to 64%), whereas specificities were 80% to 98%. These results suggest that the EIAs and toxigenic culture protocol tested are not suitable for diagnosis of C difficile infection in individual piglets.