Toxigenicity of Clostridium difficile strains isolated in the surgical ward.

We report the use of the polymerase chain reaction (PCR) for the detection of toxigenic Clostridium difficile strains. PCR was performed as described (McMillin et al., 1991). The results obtained by PCR were compared with those of cytotoxicity assays and of the latex agglutination test. Twenty seven strains cultured from stool specimens of patients and five strains isolated from hospital environment in a surgical ward were investigated. Twenty five of 32 strains produced cytotoxin as shown on the McCoy cell-line (CA). Positive reaction in the latex test was observed in 20 strains supernatants. In 24 strains PCR revealed toxin B gene fragments (1.0 kb). In the 5 strains PCR did not detect toxin B fragments, and these strains were not cytotoxic on McCoy cells. We observed 2 strains toxin B gene fragment negative, which had a low cytotoxic activity on McCoy cells, and were toxin A gene fragment positive.