CAMPYLOBACTER AGAR, PRESTON MODIFIED

Technical Data #1044a / 98.04.22

The Campylobacter Preston Modified Agar is a selective solid medium used for the cultivation and isolation of Campylobacter jejuni from fecal specimens. Charcoal, which is replacing blood, sodium pyruvate and ferrous sulfate enhance growth and aerotolerance of Campylobacter. Cefoperazone and sodium deoxycholate are the selective agents.

FORMULA
in grams per liter purified filtered water

Meat Peptone

10,0

Gelatin Peptone

10,0

Sodium Chloride

5,0

Activated Charcoal

4,0

Casein Hydrolysate

3,0

Sodium Deoxycholate

1,0

Ferrous Sulfate

0,25

Sodium Pyruvate

0,25

Agar

13,5

Cefoperazone

0,032

pH 7,3 +/- 0,2 à 25º C

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


PRECAUTIONS
This medium is for IN VITRO diagnostic use only.


STORAGE
Store prepared media at 2-8º C protected from direct light and dehydrated powder, in a dry place, in tightly-sealed containers at 2-25º C. Cefoperazone Supplement (8712) is stable to up one year if stored at -20º C.


SIGN OF DETERIORATION
Media should not be used if the expiry date has passed. Prepared media should not be used if there are signs of contamination or deterioration (shrinking, cracking, evaporation or discoloration). Do not use dehydrated media if it is caked.


DIRECTIONS
Suspend 46,5 g in 1000 ml of purified water. Heat with frequent agitation and boil for one minute. Sterilize at 121º C for 15 minutes. Cool to 45-50º C and aseptically add 10 ml of Cefoperazone Supplement (8712). Dispense into sterile Petri dishes.


PROCEDURE
Prior to inoculate, the prepared media should be brought to room temperature.

  1. Directly, inoculate plate as soon as possible with specimen and streak for isolation. If inoculation will be delayed, an Enteric Pathogen Transport Medium as EPT-100 should be used.
  2. Incubate at 42º C under a reduced O2 atmosphere for 48 hours.


QUALITY CONTROL
Results after 48 hrs at 42º C

Organisms

ATCC

Growth

Campylobacter jejuni

33291

+

Escherichia coli

25922

- or partial

Proteus mirabilis

12453

- or partial

Streptococcus faecalis

29212

- or partial

Colonies of C. jejuni will appear on Campylobacter Preston Agar as small, mucoid, flat or slightly raised, translucent and gray.


LIMITATIONS OF METHOD
Since C. jejuni is thermophilic, plates should be incubated at least 42º C. This medium is only a part of the identification. Other tests may be required.


REFERENCES

  1. Bolton, F.J., D.N. Hutchison, and D. Coates. 1984 Blood-Free Selective Medium for isolation of Campylobacter jejuni from feces. J. Clin. Microbiol. 19:169-171.
  2. Karmali, M.A., A.E. Simor, M. Roscoe, P.C. Fleming, S.S. Smith, and J. Lane 1986 Evaluation of a Blood-Free, Charcoal-Based, Selective Medium for the Isolation of Campylobacter Organisms from feces. J. Clin. Microbiol. 23: 456-459.
  3. Lennette, E.H., A. Ballows, W.J. Hausler.Jr. and H.J. Shadomy 1985 Manual of Clinical Microbiology. 4th ed. Washington D.C.: American Society for Microbiology.
  4. N.C.C.L.S. Quality Assurance for Commercially prepared Microbiological Culture Media. N.C.C.L.S. Publication M-22-A Approved Standard 1990 Vol. 10 No.14.


CATALOGUE NUMBERS

Dehydrated media 500 g QB-39-0707
     
Cefoperazone Supplement 10x5 ml 8712
     
Prepared media    
Plates, 100x15 mm 10/pkg 1044
Mono-Plates, 100x15 mm 10/pkg 1044M
     
Enteric Pathogen Transport, Vial 100/cs EPT-100
     
Campylobacter Preston Kit 6x1 L QB-KT-0707

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