Clostridium difficile toxin

Keywords: C difficile toxin, C diff toxin

Specimen:

Faeces (fresh).

Method:

Toxin detected by effect on cells in tissue culture or by EIA.

Application:

To determine the cause of antibiotic-associated diarrhoea or colitis; investigation of unexplained diarrhoea.

Interpretation:

Detection of toxin confirms the diagnosis of Clostridium difficile associated diarrhoea.

The tissue culture technique, which detects toxin B, is still the most reliable method but is time consuming and is used in only a few laboratories.

EIA tests are more practical, although less sensitive. 

Growth of C. difficile on anaerobic culture supports the diagnosis but is less definitive than toxin detection.

The test is seldom useful in infants, as C. difficile and its toxin are commonly found in the faeces of healthy infants under 2 years of age.

Reference:

Wilkins TD and Lyerly DM. J Clin Microbiol 2003; 41: 531-534.

McGowan KL and Kader HA. Clin Microbiol Newslett 1999; 21: 49-53.