Preparation and Properties of Partially Purified Erythrogenic Toxin B of Group A Streptococci

Summary Crude concentrates containing erythrogenic toxin B were prepared from filtrates or supernatants of cultures of three group A streptococci and the partially purified toxins were studied. Toxin B, like toxin A, appeared to be a protein and was not precipitable by protamine. Toxin B, unlike toxin A, was largely destroyed in the presence of trypsin. Toxin B, in contrast to toxin A, did not flocculate with anti-A antitoxin. In agar gel diffusion tests, a specific precipitin reaction of toxin B-anti-B antitoxin was not identified.