B.B.E. (BACTEROIDES BILE ESCULIN) AGAR

Technical Data #1557a / 2010.07.08

B.B.E. Agar is a selective solid medium used for isolation and presumptive identification of Bacteroides fragilis. Most gram negative anaerobes are inhibited by oxgall and gentamycin. Esculin with ferric ammonium citrate allows detection of esculin hydrolysis which produces blackening around colonies.

 

 

FORMULA

in grams per liter purified filtered water

Casein Peptone

15,0
Oxgall

20,0
Soy Peptone

5,0
Sodium Chloride

5,0
Esculin

1,0
Ferric Ammonium Citrate

0,5
Agar

15,0
Enrichment

 
Hemin

0,01
Antibiotic

 
Gentamycin

0,1

pH 7,0 +/- 0,2 at 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 or deterioration (shrinking, cracking, evaporation or discoloration). Do not use dehydrated media if it is caked.


DIRECTIONS
Suspend 40 g of dehydrated media in 1000 ml of purified filtered water. Add 20 g of Oxgall, 1 g of Esculin, 0,5 g of Ferric Ammonium Citrate and 0,01 g of Hemin and 0,1 g of Gentamycin. Heat with frequent agitation and boil for one minute. Sterilize at 121º C for 15 minutes. Cool to 45-50º C. Mix gently and dispense into sterile Petri dishes.


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

  1. Suitable anaerobes recovery is depending of collection and transportation of specimens. Specimens should be transferred into Anaerobes Pre-Reduced Transport Medium (2037) immediately after collection and brought to the laboratory quickly.
  2. Directly, inoculate plate as soon as possible with a large amount of inoculum, streak for isolation.
  3. Incubate at 35º C under anaerobic conditions for 48 hours.
  4. Examine for growth and blackening of medium.


QUALITY CONTROL
Results after 48 hrs at 35ºC anaerobic atmosphere

 

Organisms

ATCC

Growth

Blackening
Bacteroides fragilis

25285

+

+
Bacteroides thetaiomicron

29741

+

+
Clostridium perfringens

13124

-

  
Staphylococcus aureus

25923

-

  
Escherichia coli

25922

-

  

 

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


REFERENCES

  1. Dowell, V.R.Jr., G.l. Lombard, F.S. Thompson, A.Y. Armfield 1977 Media for isolation, characterization and identification of obligately anaerobic bacteria. CDC Laboratory Manual. Center for Disease Control, Atlanta
  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. Livingston, S.J., S.D. Kominos, R.B. Yee 1978 New medium for selection and presumptive identification of the Bacteroides fragilis group. J. Clin. Microbiol. 7:488-453.
  4. Sutter, V.L., D.M. Citron, M.A.C. Edelstein, S.M. Finegold Wadsworth Anaerobic Bacteriology Manual 4th ed C.V. Mosby St. Louis


CATALOGUE NUMBERS

 

Dehydrated media 500 g QB-39-5106
Oxgall 500 g QB-39-3518
Esculin 10 g QB-60-8250
Ferric Ammonium Citrate 25 g QB-63-1725
Hemin 1 g QB-61-2110
Gentamycin 1 g QB-61-1913
     
Prepared media    
Plates, 100x15 mm 10/pkg 1557
Defibrinated Sheep Blood 50 ml 4245
CNA Supplement 10x5 ml 8735