BRAIN HEART INFUSION AGAR
Code: CM1136
A solid medium which contains the highly nutritious infusions recommended for the cultivation of fastidious organisms.
| Formula | gm/litre |
| Brain infusion solids | 12.5 |
| Beef heart infusion solids | 5.0 |
| Proteose peptone | 10.0 |
| Sodium chloride | 5.0 |
| Glucose | 2.0 |
| Disodium phosphate | 2.5 |
| Agar | 10.0 |
| pH 7.4 ± 0.2 @ 25°C | |
Directions
Suspend 47g in 1 litre of distilled water. Bring to the boil to dissolve completely. Sterilize by autoclaving at 121°C for 15 minutes. Mix well and pour into sterile Petri dishes. For blood agar, cool to 50°C and enrich with 10% v/v sterile defibrinated blood.
Description
Brain Heart Infusion Agar may be recommended for the cultivation of streptococci, Neisseria and other fastidious organisms. Seth1 described the use of Oxoid Brain Heart Infusion with agar for the isolation of Neisseria gonorrhoeae. Oxoid Brain Heart Infusion Agar was designed to be equivalent in performance.
The addition of blood and antibiotics makes Brain Heart Infusion Agar suitable for the isolation of the tissue phase of Histoplasma capsulatum and other pathogenic fungi, including Coccidioides immitis2,3. For the selective isolation of fungi, without blood, cyclohexamide 0.5mg/ml and chloramphenicol 0.05mg/ml of Brain Heart Infusion Agar may be added4,5.
Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared plates of medium at 2-8°C.
Appearance
Dehydrated medium: Straw coloured, free-flowing powder
Prepared medium: Straw coloured gel
Quality control
| Positive controls | Expected results with blood |
| Neisseria meningitidis ATCC® 13090* | Good growth; grey brown coloured colonies |
| Streptococcus pneumoniae ATCC®6303* | Good growth; grey green coloured colonies |
| Negative control | |
| Uninoculated medium | No change |
*This organism is available as a Culti-Loop®
Precautions
The medium is tested for compatibility using 7% v/v oxalated horse blood, defibrinated horse blood or defibrinated sheep blood. There should be no evidence of lysis or darkening after incubation at 37°C, 25°C or 4°C for 72 hours.
When using this medium to isolate Histoplasma capsulatum, Coccidioides immitis or other pathogenic fungi which can produce free infective spores, extreme care must be taken to avoid dissemination of infective particles in the laboratory. The cultures should be examined only in a closed, filtered air cabinet.
References
1. Seth A. (1970) Brit. J. Vener. Dis. 46. 201-202.
2. Howell A. (1948) Public Health Reports 63. 173-178.
3. Creitz J. R. and Puckett T. F. (1954) Amer. J. Clin. Path. 24. 1318-1323.
4. Ajello L., Georg L. K., Kaplan W. and Kaufman L. (1960) in Laboratory Manual for Medical Mycology (CDC)
Atlanta Ga. US.DHEW. Center for Disease Control.
5. McDonough E. S., Georg L. K., Ajello L. and Brinkman A. (1960) Mycopath. Mycol. Appl. 13. 113-116.
. (1985) J. Med. Microbiol. 19. 195-201.
