Abstract
In a series of articles published in La Pediatria, Di Cristina, Sindoni, and Caronia 1 describe a small diplococcus which they are able to obtain in culture from scarlet fever. These authors attribute certain specific reactions to this diplococcus which resemble the reactions obtained with the hemolytic streptococcus isolated from cases of scarlet fever in this country. The diplococcus has been obtained in blood cultures from scarlet fever and grown in media containing fragments of guinea pig tissue. When the filtrates of these cultures are injected intracutaneously, the response is apparently identical with that resulting from an intracutaneous inoculation with a filtrate of Streptococcus scarlatinae. These authors have prepared vaccines which they believe are capable of inducing an active immunity in persons susceptible to scarlatina.
In 1925 Brokman 2 and his associates undertook a comparison of the properties of scarlatinal hemolytic streptococcus and this diplococcus of Di Cristina and Caronia. Carbolized vaccines prepared with whole cultures of the diplococcus were employed to immunize both rabbits and human subjects. In both instances serum obtained after immunization agglutinated the hemolytic streptococcus in low titre. The rabbit serum neutralized the cutaneous reaction obtained with the streptococcus filtrates. As a control experiment, rabbits were immunized with the uninoculated Tarozzi-Noguchi medium employed in culturing the diplococcus for the vaccines. Autolyzed guinea pig tissue was contained in one type of mecfium and not in the other. Serum from the rabbits injected with the first type of medium agglutinated the hemolytic streptococcus, and neutralized the toxic effects of intracutaneously injected filtrates. Several volunteers, showing positive cutaneous scarlatinal tests, were negative after immunization with this uninoculated broth. The broth without guinea tissue was impotent.
Get full access to this article
View all access options for this article.