PCR-ribotyping and pyrolysis mass spectrometry fingerprinting of environmental and hospital isolates of Clostridium difficile.

The relationships between environmental isolates of Clostridium difficile were examined by two typing methods, PCR ribotyping and pyrolysis mass spectrometry (PyMS). The 184 isolates were divided into 23 different PCR ribotypes, 13 of which were producers of toxins A and B; the remaining 10 types did not produce either toxin A or B. PyMS analysis resolved 31 groups with 60 (32.5%) isolates in one group (group 9). In both methods most of the isolates showed similar clustering. PCR ribotypes of the environmental isolates were compared with those of clinical isolates that had been typed previously. Seventeen PCR types (13 toxigenic PCR types and four non-toxigenic types) were found in both sets of isolates.