The Specific Toxigenic Properties of Haemolytic Streptococci from Scarlatina and other Sources

Abstract

1. Without exception, ninety-eight strains of haemolytic streptococci isolated from scarlet fever cases have been found to produce a toxic principle which in high dilutions is capable of evoking a cutaneous reaction in sus ceptible persons. 2. A certain proportion of haemolytic streptococci from other sources possess a similar toxigenic property. In the majority of such cases this property is only weakly developed as judged by quantitative tests. In a few instances a “toxin” is produced which is equally active with that of scarlatina strains. 3. Certain non-scarlatina strains produce “toxins” which evoke a cutane ous reaction both in known positive reactors and also in persons who do not react to a standard toxin from a scarlatina strain. 4. In the majority of cases the toxins produced by scarlatina strains are neutralised by the scarlatina antitoxic sera at present being used for therapeutic purposes, but a certain proportion of such toxins are not in the neutralised 5. The “toxins”produced by non-scaralation strains are in the majority of cases neutralised by the antitoxic sera.