Clostridium Difficle Tests

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Use

- Identification of Clostridium Difficile as a causative organism of diarrhoea (Pseudomembranous Colitis)

Tests

- Performed on stool samples

- Must be frozen if not performed by 4 hrs

- Cytotoxic Assay

- Toxin ELISA

- Stool Culture

Cytotoxic Assay

- Detects cytotoxic effect of Clostridium Difficile on cells

- 67-100% sens, 85-100% spec

- Costly, take 48 hrs

- Procedure

- Stool filtrate mixed w mammal tissue cells & observed for cytopathic effect

Toxin ELISA

- Detects Toxin A (enterotoxin) or B (cytotoxin) of Clostridium Difficile

- Wide variety of tests available

- Should look for both toxins as some strains only produce Toxin B (cytotoxin)

- Performed 3 times to confirm (3 samples)

- 63-99% sens, 75-100% spec

- Less expensive & quicker than Cytotoxic Assay

- Procedure

- ELISA w Ab to toxins

Stool Culture

- Most sens Dx measure

- Not commonly performed as costly & does not differentiate between toxigenic & non-toxigenic Clostridium Difficile