Table 2: Evaluation of pretreatment and enrichment conditions prior to multiplex PCR and bacterial cell culture for the detection of C. difficile directly from stool samples.

Pretreatment conditionEnrichment conditionIncubation time (h)Typical C. difficile colonyMultiplex PCR toxin genes detection
CCFA agar plateBHI agar plate

Alcohol shockBHIS/TA
0
1
2ND+
3+ND+
BHIS/TA/CC0
1
2ND+
3+ND+

No alcohol shockBHIS/TA
0ND
1−/+ND
2+ND+
3+ND+
BHIS/TA/CC0ND
1−/+ND
2+ND+
3+ND+

ND stands for “not determined” because there were too many contaminated bacterial species, rendering it impossible to distinguish C. difficile colonies on the plates. −/+ indicates that typical C. difficile colonies could not be observed in at least one of the three replicates.