SELECTIVE STREP B BROTH

Technical Data #2646a / 2004.06.15

Selective Strep B Broth is a selective liquid medium used for the cultivation of group B streptococci from vaginal specimens. This selective broth may be used with group B antisera to perform a slide coagglutination and may be positive without incubation if Streptococcus group B is higly concentrated in specimen.

 


 

FORMULA
in grams per liter purified filtered water

Beef Heart, Infusion

3,1

Casein/Yeast Peptone

20,0

Sodium Chloride

2,0

Disodium Phosphate

0,4

Sodium Carbonate

2,5

Dextrose

2,0

Antibiotics

 

Colimycin

0,01

Nalidixic Acid

0,015

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 2-8° C protected from direct light and dehydrated powder, in a dry place in tightly-sealed containers at 2-25° 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 (evaporation or discoloration). Do not use dehydrated media if it is caked.

DIRECTIONS
Suspend 30 g in 1000 ml of purified water. Heat with frequent agitation and boil for one minute. Sterilize at 121° C for 15 minutes. Cool to 45-50°C. Add 2x5 ml of CNA Supplement (#8735). Mix thouroughly and dispense into sterile culture tubes.


PROCEDURE
Bring prepared medium at room temperature before inoculation.

  1. Add specimen swab to the broth.
  2. Incubate at 35° C with CO2 for 24 hours.
  3. Using the standard procedures, test by slide agglutination with antisera group B.
  4. Subculture negative test, to confirm absence of group B streptococci.


QUALITY CONTROL

Expected results after 24 hrs at 35ºC W CO2

Organisms

ATCC

Growth

Streptococcus agalactiae

12386

+

Streptococcus pyogenes

19615

+

Escherichia coli

25922

-


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


REFERENCES

  1. Fenton, L.J., M.H. Harper 1979 Evaluation of colistin and nalidixic acid in Todd-Hewitt broth for selective isolation of group B streptococci.
  2. Jones, D.E., E.M. Friedl, K.S. Kanarek, J.K. Williams, D.V. Lim 1983 Rapid identification of pregnant women heavily colonized with group B streptococci. J. Clin. Microbiol. 18:558-560.
  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. Szilagyi, G., E. Mayer, A. I. Eidelman 1978 Rapid Isolation and Identification of group B streptococci from selective broth medium by slide co-agglutination test. J. Clin. Microbiol. 8:410-412.


CATALOGUE NUMBERS

Dehydrated media 500 g QB-39-4815
     
Prepared media    
Tubes, 16x125 mm, 5 ml 10/pkg 2646
Tubes 13X100 mm, 3 ml 10/pkg 2146
     
CNA Supplement 10x5 ml/pkg 8735

 


 

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