The Proteus Hemolysin

Abstract

The production of a hemolysin by organisms belonging to the proteus group was demonstrated by Kraus and Clairmont ' in 1900. Later reports have been made by Glaessner and Roscules,2 Bachrach and Grafe,3 Kostrzewski,4 Shuster,5 Baerthlein,6 Bach,7 Braun and Choa Shi-Tsing 8 and Ecker and Brittingham.' Only in rare instances does hemolysis occur when the organisms are grown on blood agar plates. Such an instance has been reported by Kline.10 The hemolysin, when present, is found in the medium, such as broth, used for culturing. Braun and Choa Shi-Tsing have shown its presence in highest concentration in 6-hour broth cultures. Ecker and Brittingham used 24-hour synthetic medium cultures. According to the latter investigators the hemolysin is heat labile, filtrable, is neutralized by proteus antiserums and is independent of the life of the organism. On the other hand Braun and Choa Shi-Tsing believed that the hemolytic activity was dependent on the active growth of the organism and were unable to demonstrate the presence of the lysin in filtered cultures. We have studied the production and properties of the proteus hemolysin formed by 26 cultures of organisms of the proteus group obtained from several sources. The series included 20 strains designated as Proteus vulgaris, three Proteus X strains, one labelled Proteus mirabilis, and one Proteus zenkeri. Only 6 of these strains, 4 Proteus vulgaris and 2 Proteus X, produced a demonstrable amount of lysin when first tested. As will be shown later, it was possible to cause all but one of the 26 strains to form hemolysin, and we believe that this lytic