Studies on The Erythrogenic Toxin of Streptococcus Pyogenes (Group A) II. On the erythrogenic toxin productivities of the strains isolated from several sources.

Abstract

According to some previous studies there is no difference in the percentage of toxin producing strains according to their sources, but the relation between the symptom and the toxin among the patients or carriers of streptococcal infection has not been made clear except in the case of scarlet fever.
The author investigated in detail the toxin productivity of each strain in regard to its source, by estimating quantitatively the toxic potency with due consideration to the growth of the microbe during the toxin production. In this study almost 100 strains freshly isolated from patients of the scarlet fever, acute nephritis and other streptococcal infections and carriers have been examined.
The results obtained were as follows:
1) Proliferative ability differed according to the sources of strains under a certain identical cultural condition, and wellgrowing strains were found in the greatest number among those isolated from the scarlet fever group, and in less numbers from the acute nephritis group, other streptococcal infections and carriers, in the order named.
2) By comparing the toxic potency of each strain according to its source, we found more strains producing a higher value of toxin in the scarlet fever group, and less in acute nephritis and carriers' groups.
Inversely the number of strains of very low or negative toxic potency was the largest in the carrier group, and very small in the scarlet fever group.
3) The neutralization test of these toxins by the antitoxic serum of “S8 strain” showed that toxins of about 30% of the strains were neutralized in every group; consequently, there may be no difference among these groups in regard to the ratio of the neutralization.