Mary W. Wheeler

Reactions induced by intracutaneous injections of toxins of streptococci from scarlet fever.

With toxins prepared in this laboratory from a strain of a scarlet fever streptococcus received from Doctor Dochez, no skin reactions were induced in rats, mice, guinea-pigs, kittens, chickens, pigeons, monkeys, sheep or a calf. Questionable reactions were obtained in two young pigs with undiluted toxin and also in four rabbits out of eighteen, the remaining fourteen giving no reactions. Definite skin reactions, however, have been induced in white goats. All fourteen goats tested gave reactions to the toxin, but individual goats appeared to vary in susceptibility. With ten, definite reactions were obtained with 0.2 cc. of a 1:500 dilution of a toxin which gives a reaction in a 1:1000 dilution in a susceptible human being. Four other goats gave reactions to lower dilutions, varying from 1:50 to 1:250. The reactions in goats reached a maximum in 18 to 24 hours and at this stage were usually quite similar to those observed in human beings. In the more susceptible goats according to the potency of the material tested, these reactions varied in degree from slightly reddish areas, 1.5-2 cm. in diameter with no swelling, to large reddish areas from 3-5 cm. in diameter with considerable swelling. All reactions, even the most severe, faded in 48 to 72 hours. With some goats, the darker color of the skin made the readings difficult. Toxin heated for one hour at 100° C. and uninoculated broth gave no reaction nor was any obtained with toxin neutralized with scarlet fever antitoxic serum, but normal horse serum, even in low dilutions did not neutralize the toxin. Toxins from another strain of streptococcus from scarlet fever, which gave no reaction in susceptible human beings in a 1:250 dilution, also induced no reaction in goats, in the same dilution.

Observations on Streptococcus Toxin-Antitoxin Neutralization as a Basis for Specificity

Practically all our experience with the interaction of the toxins and antitoxins of the diphtheria and tetanus bacilli indicates that this reaction is one of the most specific immune reactions, if not the most specific, upon which to base conclusions concerning the difference of species or of subgroups of species. In the study of the hemolytic streptococci, however, two sharply contrasted points of view concerning the specific relation of the toxins and antitoxins to the various disease processes have developed despite extensive research. Our studies of the streptococci appear to throw additional light on the nature of the toxin-antitoxin reaction and suggest why such divergent conclusions may be reached in the study of these organisms. I am, therefore, presenting these observations from this point of view. During the past 6 years the toxicity of about 200 strains of hemolytic streptococci from typical cases of scarlet fever and as many more from cases of erysipelas, septic sore throat, and other streptococcus infections has been determined. Man and goats are the only animals susceptible to the streptococcus toxins, with the possible exception of the rabbit. Different persons and different goats vary in their susceptibility to the toxins of different strains and an individual person or goat does not always react to the same degree to the same toxin. For example, in tests where 2 “scarlet fever” toxins, A and B, and 4 “erysipelas” toxins, C, D, E, and F, were tested on each of 3 individuals, person No.1 reacted in an equal degree to toxins A, B, D, and E and slightly to toxin F but failed to react to toxin C. Person No. 2 reacted equally to toxins A, B, D, and E but did not react to C or F; while person No. 3 reacted to the 4 erysipelas toxins and to the scarlet fever toxin A but failed to react to the scarlet fever toxin B. Goats susceptible to scarlet fever toxin A in high dilutions were also susceptible to all 4 erysipelas toxins.

Chloroprocaine and Pseudocholinesterase Deficiency

To the Editor.— The recent article by Freeman and Arnold (231:56,1975) suggests that chloroprocaine may be safer for paracervical block because it is rapidly degraded by fetal plasma cholinesterase. A potential hazard arises in the case of an infant with inherited pseudocholinesterase deficiency. Since this condition is inherited as an autosomal recessive trait, the parents might not have shown previous sensitivity to local anesthetics or succinylcholine but will have impaired ability to degrade these drugs. Therefore, the dose to the fetus will be increased because of sustained high levels in the mothers circulation. Although rare, this disorder should be kept in mind by physicians using these drugs.