EVALUATION OF AN OLIGONUCLEOTIDE PROBE AND AN IMMUNOLOGICAL TEST FOR DIRECT-DETECTION OF TOXIGENIC CLOSTRIDIUM-DIFFICILE IN STOOL SAMPLES

A 33 basepair oligonucleotide probe, designed from the sequence of the Clostridium difficile toxin B gene, was evaluated for its ability to detect toxigenic Clostridium difficile directly in stool samples, without culture or DNA isolation. Two different labelling techniques were investigated: radiolabelling and digoxigenin-labelling. One hundred ninety-six stools were tested, with a good correlation (96 %) obtained between the oligonucleotide probe and the gold standard, the cytotoxicity tissue culture assay. The sensitivity and specificity were 83 % and 100 %, respectively. In parallel, a new commercially available enzyme immunoassay for the detection of Clostridium difficile toxin A in stool specimens was investigated. In 162 samples tested, a sensitivity of 80 % and a specificity of 98 % were obtained.