78 DIFCOMANUAt 



bacillus and staphylococci, ordinarily considered easy to cultivate, was aided by 

 the presence of a small quantity of agar. They also showed that growth is 

 initiated in a much shorter incubation period in such media. They used 0.1 per 

 cent agar in their routine tests. Bacto-Brain Heart Infusion with PAB and 

 Agar, as discussed below, contains 0.1 per cent agar. 



Dance and Murray^ used Bacto-Brain Heart Infusion with 0.1 per cent 

 added agar for the cultivation of hemolytic streptococci in their study of hemo- 

 lytic properties on various Blood Agars. Berens, Nilson and Chapman^ added 

 3 grams calf brain to 10 ml. of Brain Heart Infusion for the growth of bacteria 

 from patients with certain inflammatory eye diseases. Chapman, Stiles, and 

 Berens^ and Chapman^ used Bacto-Brain Heart Infusion in their test for 

 pathogenicity of streptococci. Reitzel and KohP added 30-50 per cent sterile 

 ascitic fluid to Bacto-Brain Heart Infusion and stated that some of the gono- 

 cocci grew more readily in this medium than in a Hormone Brain Broth con- 

 taining sterile pieces of brain. They also used Bacto-Brain Heart Infusion in 

 combination with Bacto-Brain Veal Agar and Bacto-Hemoglobin for the isola- 

 tion of the gonococcus. A detailed discussion of these products is given on 

 pages 94 and 271. 



The coagulation of plasma is one of the characteristics of pathogenic staphy- 

 lococci. Brain Heart Infusion is especially well suited for the growth of staphy- 

 lococci or for the preparation of the suspension of the organism used in the 

 performance of the Coagulase Test, as described by Chapman.^o A complete 

 discussion of the performance of this test is given under Bacto-Coagulase Plasma, 

 page 330. Newman,ii in a study of the detection of food poisoning attributable to 

 dairy products, used staphylococci grown in Brain Heart Infusion for the per- 

 formance of the coagulase test. 



Neter ^^.is added Bacto-Supplement B to Brain Heart Infusion and demon- 

 strated that Hemophilus influenzae could be cultivated on this medium through 

 serial transfers. He also used this enriched Brain Heart Infusion in tests designed 

 to determine the streptomycin sensitivity of strains of H. influenzae, 



Bacto-Brain Heart Infusion has been used in the preparation of media for the 

 isolation of pathogenic fungi. Roseburg, Epps and Clark^* found that Bacto- 

 Brain Heart Infusion, containing 2 per cent agar, was more satisfactory than 

 Dextrose Infusion Agar, for the isolation and cultivation of Actinomyces israeli. 

 Incubation in a 5 per cent carbon dioxide atmosphere was required for best 

 results. The addition of sheep blood to the medium was not an advantage. 

 Howell^^ used Bacto-Brain Heart Infusion to which was added 2 per cent Bacto- 

 Agar and 10 per cent sterile defibrinated horse blood for the cultivation of 

 Histoplasma capsulatum. A selective medium for this microorganism was pre- 

 pared by adding 40 units of streptomycin and 20 units penicillin per ml. of 

 medium. In comparison with a Blood Agar similarly prepared from Potato 

 Dextrose Agar, the Brain Heart Infusion medium gave a greater number of 

 positive isolations. Incubation at room temperature was more efficient than at 

 37 °C. Colonies isolated on the Brain Heart Infusion Blood Agar must be trans- 

 ferred to a medium such as Potato Dextrose Agar to obtain the characteristic 

 tuberculate chlamydospores typical of H. capsulatum. Conant^^ recommended 

 that a plate of Bacto-Brain Heart Infusion Agar be streaked and incubated at 

 37 °C. under anaerobic conditions with the addition of 5 per cent carbon dioxide 

 to obtain growth of the microaerophilic Actinomyces hovis in culturing this 

 organism from infected mucous membranes, skin and subcutaneous tissues. 



For blood culture work a procedure frequently used is to add as much as 

 10 ml. of blood specimen to 150 ml. of sterile Brain Heart Infusion contained 

 in a 300 ml. Erlenmeyer flask or bottle. This is incubated at 37 °C. and trans- 

 fers are made to Blood Agar or other media for the isolation and identifica- 



