TODD HEWITT BROTH

Technical Data #2103a / 2013.06.23

Todd Hewitt Broth is a liquid nutrious medium primarily used for the cultivation of hemolytic streptococci, especially for serological studies. Peptones are the nutrious source; dextrose stimulates hemolysin production; phosphate and carbonate salts neutralize the products of fermentation.

 


 

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

pH 7,8 +/- 0,2 25 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 2-8 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. Mix thouroughly and dispense into culture tubes. Sterilize at 121 C for 15 minutes.


PROCEDURE
Bring prepared medium at room temperature before inoculation.

  1. Inoculate directly with specimen swab.
  2. Incubate aerobically 2-5 hours at 35 C for the fluorescent antibody procedure.
  3. Incubate aerobically 18-24 hours at 35 C for the extraction procedure and streak on Blood Agar plate.


QUALITY CONTROL

Expected results after 24 hrs at 35C

Organisms

ATCC

Growth

Streptococcus pyogenes

19615

+

Streptococcus pneumoniae

6305

+

Enterococcus faecalis

29212

+


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


REFERENCES

  1. 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
  2. Mac Faddin, Jean F. 1985 Media for Isolation-Cultivation-Identification-Maintenance of Medical Bacteria. Vol. 1, Baltimore, MD.: Williams & Wilkins
  3. Todd, E.W., Hewitt, L.F., 1932 A new culture medium for the production of antigenic streptococcal haemolysin. J. Pathol. Bacteriol. 35:973.


CATALOGUE NUMBERS

Dehydrated media 500 g QB-39-4815
     
Prepared media    
Tubes, 13X100mm, 0,5ml 10/pkg 2451
Tubes, 13X100mm, 2ml 10/pkg 2690
Tubes, 16X125mm, 5ml 10/pkg 2103

 


 

 

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