The Toxigenic Properties of Hemolytic Streptococci from Human Infections

Abstract

Summary In a comparative study of 471 cultures of hemolytic streptococci from human infections, no relationship was detected between the type or severity of the infectious process from which a culture was isolated and its toxigenic activity or virulence for mice. The incidence of virulent strains was highest among cultures isolated from cases of severe suppurative infections, excluding meningitis. Although, by means of toxin-antitoxin neutralization tests, toxigenic strains were divided into several distinct groups, no evidence of the specificity of any of these groups for a particular type of infection was obtained. According to toxin-antitoxin neutralization tests, antistreptococcus sera varied markedly in valency, depending upon the strains used in their production. Serum of the Dochez N. Y. 5 strain was of broadest valency, neutralizing approximately 77 per cent of the toxins. Two other monovalent sera were each effective against different groups of the remaining toxins, representing 21 per cent of the total. Of 314 toxigenic strains, 5 were encountered, the toxins of which were neutralized only by combinations of one or the other of these sera with that of the N. Y. 5 strain.