EFFECT OF SERA ON THE HEMOLYTIC REACTION OF A PATHOGENIC BOVINE STRAIN OF B. COLI

In this work the same hemolytic strain of B. coli (1192) was used that is described in the immediately preceding paper. In the literature on inhibition of hemolysis by sera, first in regard to B. coli hemolysis, Kolle and Wassermann (1913) mention Kayser's report that hemolysis by B. coli was prevented by dog, rabbit, and human sera. Dudgeon, Wordley and Bawtree (1921-1922) found that human serum in certain concentrations prevented hemolysis by their B. coli strains. By comparing the action of the serum with that of a 6 per cent gum solution which had little effect on hemolysis they concluded that the action of serum in prevent-ing hemolysis was something apart from mere mechanical protec-tion. There are other references to the inhibiting effect of sera on hemolysis produced by other organisms or substances. Weinberg and Otelesco (1921) stated that normal horse serum possessed an anti-hemolytic power against B. proteus and that it also exerted an anti-infecting power proportional to its anti-hemolytic proper-ties. Cole (1914) noted an anti-hemolytic action of serum for pneumococcus hemotoxin and related it to the cholesterol or lipoid content of serum. Braun and Shi-Tsing (1922) reported B. proteus hemolysis as inhibited by immune but not by normal sera. Ponder (1923-1924; 1925; 1927) studied saponin hemolysis and reported that it was inhibited by serum. From his experi-ments he concluded that it was the protein of the serum and to a less extent the cholesterol that were the inhibiting factors. He noted that horse and human serum had a greater inhibiting power than rabbit, guinea pig, cat or mouse serum. Also he considere