Hydrogen ion Concentration and Anticoagulating and Fibrinolytic Action of Cultures of Streptococci and Pneumococci

Abstract

Recently Neter and Witebsky 1 , 2 have reported that many strains of Streptococcus viridans and pneumococcus were found to be fibrin-olytic for human fibrin provided the organisms with which the tests were performed were grown in broth containing 2% dextrose. Tunnicliff 3 reported that strains of Streptococcus viridans were incapable of dissolving normal fibrin clot but that cultures of smooth forms inhibited coagulation. The latter author used for liquid culture medium meat extract broth containing one percent dextrose. Dennis and Berberian 4 reported that some strains of Streptococcus hemolyticus and viridans inhibited the formation of fibrin in plasma. They stated that 2% dextrose broth gave more active cultures than did 0.5% dextrose broth.

Because of the experience in this laboratory, using culture media containing 0.05% dextrose, that neither strains of Streptococcus viridans nor Pneumococcus have been encountered which were capable of dissolving human fibrin under the experimental conditions previously described, 5 additional observations have been made with special consideration being given to the dextrose content of the culture media in which the organisms were cultivated in relation to anticoagulating and fibrinolytic activity of strains of Streptococcus hemolyticus, Streptococcus viridans, and Pneumococcus.

Culture Media. Plain meat infusion broth containing one percent neo-peptone but no buffer, has been employed. Before use, the pH was adjusted to 7.4-7.6. Dextrose has been added to make concentration of 0.05%, 1.0%, and 2%.

Strains: Streptococcus hemolyticus. Ten strains derived from patients suffering from acute infections were employed. These strains were all known to be actively fibrinolytic.

Streptococcus viridans. Thirty-three strains, all of which were derived from patients with endocarditis, were tested.

Pneumococcus. Ten strains, all derived from patients with lobar pneumonia, were used.

All the cultures were approximately 18 to 24 hours old when used.