Identification of toxigenic Clostridium difficile strains using a toxin B gene-specific oligonucleotide probe

We describe the use of a new specific synthetic oligonucleotide probe, deduced from the sequence of the gene for Clostridium difficile toxin B, to identify toxigenic strains of C. difficile. This probe does not hybridize to the DNA of non-toxigenic strains of C. difficile nor to DNA isolated from different Clostridium species, including C. sordellii. None of the enteric pathogenic bacteria tested were seen to hybridize with the probe. A preliminary study of direct probing of faecal specimens indicates a potential for the use of this DNA probe in the clinical laboratory for the rapid identification of toxigenic strains of C. difficile.