Thermostable Toxin Research Articles

Rheumatic Fever: Bacteriologic Studies of a Non-Methemoglobin-Forming Streptococcus with Special Reference to its Soluble Toxin Production

Recent studies on the production of soluble toxins by Streptococcus scarlatinae,1 Streptococcus erysipelatis,2 and certain strains of Staphylococcus aureus,3 suggested a study of possible toxin production by a series of other streptococci. The first indication of a toxin producing streptococcus associated with rheumatic fever was obtained by the author in March, 1926, when an unusual strain of a nonhemolytic and non-methemoglobin-forming streptococcus was repeatedly isolated from blood cultures taken from a 5 year old girl, admitted to the Strong Memorial Hospital, on March 23, 1926. The patient was found to be ill with acute rheumatic fever, endocarditis, myocarditis, pericarditis, and pleurisy. On March 31 the patient expired and at autopsy, the clinical diagnosis was confirmed. From the vegetations on the mitral valves a streptococcus was isolated, identical biologically with the organism obtained from blood cultures during life. At that particular time, our laboratory was engaged in the study of soluble toxins produced by streptococci associated with scarlet fever and erysipelas. The strains of non-methemoglobin-forming streptococci isolated from the case of rheumatic fever, labelled in these studies as RF. 1, were found to produce a potent, soluble, thermostable toxin, similar in many respects with those produced by the scarlet fever and erysipelas streptococci. Perhaps, more striking than their ability to produce a soluble toxin, was their action upon the complex carbohydrates, in that they consistently fermented inulin and salicin, and differed definitely from the pneumococcus in that they remained bile insoluble. The unusual biological character-