A Dialyzable Medium for Cultivation of Group A Hemolytic Streptococci.

Abstract

The dialyzable components of the standard Todd-Hewitt medium support heavy growth of pathogenic group A hemolytic streptococci. A procedure is described for extraction of beef heart and commercial peptone by dialysis. These purified ingredients are supplemented with glucose, salts and water to form the completed medium. A reduction of at least 8-fold in the quantity of meat required is made possible by avoidance of heating. A medium of this type facilitates the recovery of metabolic products from the culture filtrates. It is also advantageous for iramun-ological work with filtrates since the non-dialyzable antigenic material, otherwise introduced with crude meat and peptone, should be substantially eliminated.