CLOSTRIDIUM DIFFICILE SCREENING TUBE

Technical Data #2292a / 2005.02.28

The C.difficile Screening Tube is a new one step method for screening rectal swabs for the presence of C.difficile. The growth is assured by a special mixture of peptones enriched by anaerobic growth stimulants. The selectivity is based on the presence of an antibiotic mixture which inhibits most of all intestinal germs except C.difficile. The identification is highlighted by a specific chemical reaction which turns the medium to yellow. The presence of cysteine creates a free oxygen atmosphere, avoiding to pre-reduce the tube medium before its use.

FORMULA
in grams per liter of purified filtered water

Special mixture of peptones	20,0
Yeast Extract	3,0
Dextrose	1,0
Sodium Chloride	5,0
Cystein HCl	0,5
Neutral Red	0,03
Growth Supplements	10,15
Antibiotics mixture	0,52
Agar	13,5

pH 7.6 +/- 0,2 à 25º C

This approximate formula may be adjusted and/or enriched to obtain best results.

PRECAUTIONS
This medium is for laboratory use only.

STORAGE
Store prepared media at 2-8º C protected from direct light.

SIGNS OF DETERIORATION
The appearance of the medium is an orange-reddish agar. The medium must not be used if there are signs of contamination, dehydration, change of color or if the expiry date has passed.

INSTRUCTIONS FOR USE

1. Bring the tube to room temperature before using it.
2. Take a swab of patient's rectum.
3. Unscrew the cap of the tube and dip the inoculated swab up to the bottom of the tube.
4. Break top of the swab at score line and screw on cap.
5. Identify the tube and place it in a Bio Hazard bag.
6. Bring as soon as possible to the laboratory along with a duly filled requisition.

Note. Alternatively the swab may be inoculated directly in liquid stools and place in tube up to the bottom.

PROCEDURE

1. Incubate the tube at 35º C under anaerobic atmosphere for 18-24 hours with loosened cap.
2. A yellow deep with gas in the bottom of the tube is a positive reaction for the presence of C.difficile.
3. Incubate for an extra 24 hours if there is no change of the color.
4. If the interpretation must be postponed, keep the tube between 2-8º C.

QUALITY CONTROL
Results after 24 hrs at 35ºC anaerobically

Organisms	ATCC	Growth	Colour
Clostridium difficile	9689	+ w/Gas	Yellow
Escherichia coli	25922	-
Staphylococcus aureus	25923	-

LIMITATIONS OF METHOD
This test is intended for presumptive identification of C.difficile. Other test may be required including the toxin detection.

REFERENCES

1. George, W.L., V.L. Sutter, D. Citron and S.M. Finegold 1979 Selective and differentiel medium for Isolation of Clostridium difficile. J. Clin. Microbiol. 9:214-219.
2. Landry, L.M., J.Topal, D. Ferguson, D. Giuditti and Y. Tang 2001 Evaluation of Biosite Triage Clostridium difficile Panel for Rapid Detection of Clostridium difficile in Stool Samples J. Clin. Microbiol. 39:1855-1858.
3. Lennette, E.H., Ballows, A., Hausler, W.J.Jr., and Shadomy, H.J. Manual of Clinical Microbiology. 4th ed. 1985 Washington D.C.: American society for Microbiology.
4. Mac Faddin, Jean F., 1985 Media for Isolation-Cultivation-Identification-Maintenance of Medical Bacteria Vol.1 Baltimore, MD. Williams & Wilkins.
5. Personnal Communications.

CATALOGUE NUMBERS

Prepared media
Tube 13x100 mm, 4 ml	10/pkg	2292
Collection kit which contains 50 C.difficile tubes and 50 sterile swabs		2292-K

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