Faeces for C. difficile investigation

Clostridium difficile is a Gram positive, spore forming, strictly anaerobic organism that is a major nosocomial pathogen. It can cause a spectrum of intestinal diseases ranging from mild uncomplicated antibiotic associated diarrhoea (AAD) to severe and potentially fatal antibiotic associated pseudomembranous colitis.
C.difficile is unable to successfully compete in the normal intestinal ecosystem; however when the balance of the microflora of the intestinal tract is altered by antibiotics and chemotherapeutic agents, C.difficile is able to compete and colonise the intestinal tract. The organism will then replicate and secrete two toxins, toxin A and Toxin B. Toxin A is an enterotoxin that causes fluid accumulation in the bowel and is a weak cytotoxin for mammalian cells where as Toxin B is a potent cytotoxin. Turn around time 24 hrs.
Clinical details: 
Pathology is usually limited to the colon, indeed the most frequently implicated drugs in CDI are those which have a marked effect on the microflora of the colon, these include ampicillin, amoxycillin, cephalosporins and clindamycin. However, almost all drugs with an antibacterial spectrum of activity have been implicated causally in antibiotic associated diarrhoea. Patient groups that are at a particular risk of acquiring C.difficile disease include those undergoing general surgery, oncology patients, those with chronic renal disease, patients aged over 65 years. Symptoms of acute onset of diarrhoea, often abdominal pain and fever, usually after a course of antibiotics. C. difficile testing in children under 2 years of age rarely indicated
Synonyms or keywords: 
CDT screen, antibiotic associated diarrhoea
Sample type and Volume required: 
Faeces CDT screen
2gm or 2ml of diarrhoeal faeces in a sterile universal container white top or blue top (with a scoop forming part of the lid)
samples received by 15.00 will be tested same day.
Turnaround time: 
24 hrs. Positive results are telephoned to the ward or clinical team by Infection Control Team or Microbiology clinical staff if an inpatient, if outpatient the ordering clinican will be contacted by the Infection Control team.
Special sample instructions: 

Formed faecal samples will NOT be tested.

Storage and transport: 
Please place labelled container in a sealed transport bag and send to Central Specimen Reception (CSR). Samples should be refrigerated if transport to the laboratory is delayed. Samples must be tested within 72 hours.
Infection Sciences Department at St Thomas' Hospital
020 7188 8008
St Thomas' Hospital
North Wing - 5th Floor
Westminster Bridge Road
London SE1 7EH
Core opening hours: Monday-Friday 0900-1730

For clinical advice or interpretation of results, please contact the laboratory in the first instance.

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Last updated: 27/11/2017