HEMOLYTIC STAPHYLOCOCCI 



11 



others, that carbohydrates prevent hemolysis by streptococcus, and it 

 was problematic just what their effect on staphylococcus hemolysis 

 would be. Two experiments were carried out to determine this point. 

 In the one case, cultures were planted into 10% serum broth plus 1% 

 dextrose. After 9 days tests were made for hemolysis and H-ion 

 concentration read to assure ourselves that an acidity would not inter- 

 fere with the test. The results were: for 10% serum broth, dextrose 

 1%, strain A5 gave P H 6.4, hemolysis and strain T9, P H 7.6 and 

 hemolysis. 



Incidentally both these strains were streaked on lactose-blood-agar 

 plates, and in both cases hemolysis was produced within 24 hours. In 

 the second case, cultures were planted into peptone broth plus \% 

 dextrose. The test for hemolysis was positive after 24 hours, but the 



TABLE 4 

 HEMOLYTIC ACTIVITY OF CONSECUTIVE CULTURES 



hemolysis was not typical, showing a browning similar to acid hematin 

 formation. Consequently the PH value was determined and found to 

 be 4.4. The reaction was adjusted to neutrality and hemolysis no longer 

 took place. Approaching the question from another tangent, sterile 

 salt solution adjusted to a reaction of P H 4.4 caused the same type of 

 hemolysis. 



It would seem from these experiments that carbohydrates do not 

 influence hemolysis as produced by staphylococcus. Regarding the 

 acidity produced in the peptone broth and not in the serum broth, it is 

 easily conceivable that the buffer qualities of the serum in the latter 

 obscure the acid formed by fermentation of dextrose. 



