Clostridium difficile toxins A&B profile

Specimen Container

Screw capped leak-proof stool container

Specimen Requirement

Fresh stool (about 1 teaspoon or 10 mm³ stool). Only unformed stool is acceptable.

Specimen Storage / Transport

If it is not possible to despatch the stool sample to the laboratory on the same day, the sample should be kept at 2-8°C in a refrigerator.

Note: Stool in transport media, on swabs, mixed in urine or preservatives, is not appropriate for testing and will have to be rejected. Sample should reach laboratory as soon as possible, preferably within 24 hours after collection.

Method

Orderable as STAT?

No

Turn Around Time

1 day

Reference Value(s)

Testing Laboratory Location

SGH

Laboratory

Immunology/Serology

Contact Number

6394 1352

Day and Time Performed

Mon - Fri: 0800 hrs to 1700 hrs
Sat: 0800 hrs - 1230 hrs

Orderable on CPOE?

Yes

Downtime Form

Bacteriology, Mycology,Parasitology Tests

Additional Information

C. difficile Testing Algorithm: Results, Interpretation and Action

Test	EIA Test Results*	Interpretation	Action after EIA results
Clostridium difficile Toxins A & B Profile	Toxins: Not detected	NO toxigenic C. difficile detected	EIA results reported; no further action
	GDH: Not detected
	Toxins: Detected	Toxigenic C. difficile detected	EIA results reported; no further action
	GDH: Detected
	Toxins: Not detected	Indeterminate	EIA results reported and reflex-testing to C. difficile PCR** with separate PCR report
	GDH: Detected
	Toxins: Detected	Indeterminate	EIA results reported and reflex-testing to C. difficile PCR** with separate PCR report
	GDH: Not detected

This test involves an algorithm whereby all stool specimens will be first tested by C. difficile Toxins A&B and glutamate dehydrogenase (GDH) enzyme immunoassays (EIAs) in the SGH Immunology/Serology Laboratory. All specimens with concordant results will be reported accordingly (see Table). Specimens with indeterminate EIA results will be sent automatically to the SGH Molecular Laboratory for C. difficile toxin gene PCR testing. A separate PCR report will then be issued. This ‘reflex’ PCR testing does not require any further action by the ordering clinician, and involves no additional cost.
Questions may be directed to Dr Matthias Maiwald (6394 1389) at the KKH Microbiology Laboratory.