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