Fibrinolytic Activity of Beta Hemolytic Streptococci from Cow's Milk

Abstract

One of the many unsettled problems concerning mastitis is its relationship to the organism designated as S. mastitidis. While the majority of workers agree that this relationship must be a very significant one, any new approach to the study of this subject should be of interest. Tillet and Garner found that many beta hemolytic streptococci from human diseases were capable of causing specific lysis of human plasma clots. Negative fibrinolytic tests were observed with other bacterial species from human sources, and strains which would actively lyse human plasma clots would not cause the dissolution of rabbit fibrin. Later Tillet stated, “There is a relationship between the infectivity of beta hemolytic streptococci for man and the fibrinolytic property of the cultures.” Madison confirmed the work of Tillet and Garner and further tested strains from horse, rabbit, man, and hog. The lytic action of each strain was determined on fibrin from horse, hog, cow, rabbit, and man, but he did not test organisms from the cow on bovine plasma or fibrin. Thus, no conclusions could be drawn respecting the applicability of these tests to the study of S. mastitidis. If the organism usually associated with infectious mastitis in the cow is able to lyse bovine fibrin, then fibrinolysis may offer a useful method of studying the r6le of this organism in mastitis.