BILE ESCULIN AZIDE AGAR

Technical Data #1312a / 2013.05.04

Bile Esculin Azide Agar is a highly selective culture medium used for the isolation of group D streptococci. Esculin hydrolysed by group D enterococci give a dark brown colour. Gram-positive bacteria other than enterococci and Gram-negative are inhibited by sodium azide.

 


 

FORMULA
in grams per liter purified filtered water

Casein Peptone

17,0

Meat Peptone

3,0

Yeast Extract

5,0

Oxgall

10,0

Esculin

1,0

Sodium Chloride

5,0

Sodium Citrate

1,0

Ferric Ammonium Citrate

0,5

Sodium Azide

0,15

Agar

15,0

pH 7,1 +/- 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.


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 (shrinking, cracking, evaporation or discoloration). Do not use dehydrated media if it is caked.


DIRECTIONS
Suspend 58 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. Mix thouroughly and dispense into Petri dishes.


PROCEDURE
Bring prepared medium at room temperature before inoculation.

  1. Directly, inoculate the specimen and streak for isolated colonies.
  2. Incubate at 35º C for 24 hours.


QUALITY CONTROL

Expected results after 24 hrs at 35ºC

Organisms

ATCC

Growth

Blackening

Streptococcus faecalis

29212

+

+

Streptococcus pyogenes

19615

- or partial

-

Escherichia coli

25922

- or partial

-


LIMITATIONS OF METHOD
This medium is only a part of the identification. Other tests may be required.


REFERENCES

  1. Isenberg, H.D., D. Goldberg, J. Sampson 1970 Laboratory studies with a selective enterococcus medium. Appl. Microbiol. 20(3):433
  2. 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.
  3. Mac Faddin, Jean F. 1985 Media for Isolation-Cultivation-dentification-Maintenance of Medical Bacteria. Vol. I, Baltimore, MD.: Williams & Wilkins.
  4. N.C.C.L.S. 1990 Quality Assurance for Commercially Prepared Microbiological Culture Media Approved Standard. Vol. 10, No. 14, NCCLS Document M22-A.


CATALOGUE NUMBERS

Dehydrated media 500 g QB-39-0118
     
Prepared media    
Pétri 100x15 mm 10/pkg 1312
Mono-plates, 100x15 mm 10/pkg 1312M

 


 

 

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