Clostridium difficile

• Large Gram positive anaerobic bacillus that forms spores.
• Normal gut commensal in neonates.
• Produces an enterotoxin (toxin A) and a cytotoxin (toxin B) which cause clinical disease.
• C. difficile toxin is detected in stool culture by cell culture techniques or by enzyme linked immunosorbant assay (ELISA).
• C. difficile can be cultured but this is not routinely done in microbiology laboratories.

Main Clinical Infection:

• Antibiotic associated diarrhoea - can range from mild diarrhoea to life-threatening pseudomembranous colitis.
• Antibiotics disrupt bowel flora allowing colonisation with C. difficile, acquired following germination of ingested spores

Usually sensitive to:

• Metronidazole
• Vancomycin (given orally)

Usually resistant to:

• Cephalosporins
• Co-amoxiclav
• Macrolides (erythromycin, clarithromycin)
• Clindamycin

The following antibiotics seldom trigger C difficile infection:

• Trimethoprim
• Doxycycline
• Gentamicin
• Benzylpenicillin

Click here for advice on management of C.difficile diarrhoea.

Page last edited: 28/09/2006

Caution; the antibiotic doses recommended on this website are intended for adult patients with normal renal and liver function unless otherwise stated. Dosing advice for patients with renal impairment is available here.

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