Effect of Bacteriophage Upon the Agglutination of Hemolytic Streptococci.

Abstract

There exists a definite effect of the bacteriophage upon the phenomenon of agglutination in the coli-typhoid-dysentery group, as is seen from papers by d'Herelle, 1 Bordet, 2 Gratia 3 and others. Since the studies on this problem were confined exclusively to the colityphoid-dysentery group, it was thought desirable to extend them to hemolytic streptococci in which the phenomenon of bacteriophage was shown to exist, Dutton, 4 Shwartzman. 5

The effect of two lytic principles upon various strains of pathogenic streptococci which differed in their antigenic structure and their susceptibility to these principles, was investigated. The results may be grouped as follows:

1. The first group of changes of a whole culture was observed with a strain of scarlet fever streptococci grown in broth containing lytic principle. The changes consisted of complete inagglutinability by the normal culture serum; considerable loss of agglutinin absorbing power, and partial loss of agglutinogenic power. Two rabbits persistently immunized with this antigen responded with agglutinins of a low titer (1:400). The same method of immunization with the normal culture gave sera of titer 1:12,800.

2. When a strain highly susceptible to phage was made resistant to this principle it underwent changes which were still more marked than those described above. These changes manifested themselves in complete inagglutinability, complete loss of agglutinin absorbing and agglutinogenic properties.