Description

A general purpose nutritious agar base. This medium was first used for the isolation of dental pathogens. The mixture of brain and heart infusions is particularly useful in the isolation of Actinomyces israeli and Histoplasma capsulatum. With the addition of 7% defibrinated blood the medium will support the growth of a wide range of fastidious organisms, the phosphate buffer will help neutralise the acids produced from the utilisation of glucose and thus maintain viability. The medium is not recommended for the determination of haemolytic reactions because of the glucose content.

The use of porcine material in this product ensures there are no Specified Risk Materials (SRM'S) with respect to Transmissible Spongeform Encephalopathies (TSE'S).

Method for reconstitution

Weigh 49 grams of powder, disperse in 1 litre of deionised water. Allow to stand for 10 minutes then swirl to mix. Sterilise by autoclaving at 121˚C for 15 minutes. Cool to 47˚C then pour into Petri dishes.

Appearance: Pale Straw colour, clear gel.

pH: 7.4 ± 0.2

Minimum Q.C. organisms: S. aureus NCIMB 50080 E. coli NCIMB 50034

Storage of Prepared Medium: Plates - up to 7 days at 2-8˚C in the dark. Capped container - up to 3 months at 15-20˚C in the dark.

Inoculation: Surface, streaking out to single colonies.

Incubation: Time and temperature to suit specimen/organisms.

References

Roseburg. T., Epps, L.J. and Clarke, A.R. (1944). A study of the isolation, cultivation and pathogenicity of Actinomyces israeli recovered from the human mouth and from actinomycosis in man. J. inf. Dis., 74: 131-149.

Howell, E. (1948) Efficiency of methods of isolation of Histoplasma capsulatum. Pbl. Hlth. Rep. 63: 173-178. 3/108

Description

A rich isotonic infusion medium with tryptose (a mixture of meat milk  peptones)  providing  a  wide  range  of  substrates. A concentration of glucose is used to stimulate early growth. medium is lightly buffered to prevent the early death of some spe due to  acid  production.  Organisms  which  produce  signific amounts of acid may well overwhelm the buffering system and a sterilise. The medium is suitable for use as a blood culture medium as an enrichment broth for fastidious organisms.

The use of porcine material in this product ensures there are Specified Risk Materials (SRM'S) with respect to Transmiss Spongeform Encephalopathies (TSE'S).

Method for reconstitution

Weigh 37 grams of powder then disperse in 1 litre of deionised wa Allow to stand for 10 minutes then dissolve with gentle heat before dispensing into tubes or bottles. Sterilise at 121˚C for 15 minutes. Overheating will cause caramelisation and darkening of the medium.

Appearance: Straw colour, clear liquid.

pH: 7.4 ± 0.2

Minimum Q.C. organisms: S. aureus NCIMB 50080 E. coli NCIMB 50034

Storage of Prepared Medium: Capped container - up to 3 months at 15-20˚C in the dark.

Inoculation: (as a blood culture medium). Using a minimum volume of 50ml of medium add the blood to a dilution of from 1:10 to 1:20. Use in conjunction with an anaerobic culture medium e.g. Fastidious Anaerobe Broth LAB 71.

Incubation: 37˚C aerobically for 7 to 15 days.

Interpretation: Observe daily, subculture after 1, 2, 3, 7 and 15 days or immediately on showing signs of growth.

References

Rosenow. E.C. (1919). Studies on selective localisation; focal infection with special reference to oral sepsis. J. Dent. Res. 1:205-267.