A Powerful Bacteriophage Against Hemolytic Streptococci of Erysipelas Origin.

Abstract

Attempts by several authors to obtain an active lytic principle against streptococci were without definite results. Successful attempts with single strains were reported by Piorkowsky, 1 Dutton. 2 Hadley and Dabney, 3 Clark and Clark. 4 Only two strains were of human origin (Piorkowsky, Dutton). It remains yet to decide as to whether streptococci as a genus are susceptible to the bacteriophage phenomenon, or whether the few strains of streptococci, in which this phenomenon was observed, carried a factor, not common to other streptococci as a genus, which enabled them to be affected by the phage. In this work attempts were made to obtain a lytic principle against human pathogenic streptococci by means of various lytic principles, namely: anti-B coli phage; anti-staphylococcus phage; lytic principle isolated by Clark and Clark from activated sludge against a strain of rabbit streptococcus hemolyticus. Numerous human strains proved to be entirely resistant towards these phages. One hundred and two strains were tested against Clark and Clark's phage. These human strains also completely lacked the power of regenerating these principles. Since the power of regeneration is essential for obtaining classical bacteriophage phenomenon, various resistant strains were placed under supposedly favorable conditions to enable them to perform this function. All these attempts failed. An effort was then made to “train” the pathogenic strains to regenerate bacteriophage by “adapting” the microorganisms to the lytic principles, instead of the usual method, of adaptation of lytic principle to the microorganisms. Various strains of human pathogenic streptococci chosen for this experiment were subcultured every 24 hours in broth containing 1:10 dilution of lytic principle. After several such passages the cultures were inoculated into flasks of broth, incubated for 24 hours, and 0.5 cc. of each of these filtrates tested against homologous normal cultures of streptococci.