Culture filtrates of hemolytic streptococci from scarlet fever: Intracutaneous reactions in test animals.

Abstract

A number of substances poisonous for animal cells have been described as appearing in filtrates of young cultures of hemolytic streptococci. The presence of hemolysin (Besredka, 1901) and leucocidin (Ruediger, 1905) with the production of an antiserum for the latter and not for the former has been many times corroborated. The presence of a specific exotoxin (Clark and Felton, 1918, Havens and Taylor, 1921) has been denied by Zinsser, Parker and Kuttner (1921), who state that they find in these young culture filtures only non-specific low grade poisons (called “X substances” by them) that do not stimulate the production of antiserums. For all this work, the animal tests of the poisonous products were made only by way of the veins, the subcutis or the peritoneal cavity. Zinsser reports only intravenous inoculations. The latest and most suggestive announcement has just been made by the Dicks. They have a toxic filtrate obtained from cultures of hemolytic streptococci from scarlet fever, that gives an intracutaneous reaction in people presumably susceptible to scarlet fever, that is neutralized by serum from scarlet fever convalescents, and that gives no intracutaneous reaction in scarlet fever convalescents. The Dicks kindly sent us some of their toxic filtrate, and Dr. Zingher in our laboratory has fully corroborated the Dicks' use of their test in humans. We have obtained similar toxic filtrates from the hemolytic streptococci we have isolated from scarlet fever cases. According to Dr. Zingher's tests, these act in humans as does the filtrate obtained from the Dicks. Our methods of growth will be given later. As the Dicks have not yet published their culture methods in detail, we cannot say how ours agree. We have found that the intracutaneous injection of these filtrates into young depilated rabbits gives a very clear cut reaction and that the filtrates are neutralized by serum from convalescent scarlet fever patients.