CHAPTER XIV 



TOXINS AND ANTITOXINS 



Toxins Defined. — In earlier chapters antigens have been de- 

 fined as colloids (thought to be invariably proteins or protein- 

 hapten complexes) which when injected into the blood stream, 

 body cavities or tissues of a suitable animal, stimulate the pro- 

 duction of specific reacting substances (antibodies). Toxins are 

 antigenic poisons (Coca, 1925). Their antigenic property sets 

 them off from all other poisons since it is well established that 

 neutralizing substances are never produced against cyanide, 

 strychnine, morphine, ptomaines, endotoxins, etc., but only against 

 true toxins. Attention has also been called to the various kinds 

 of toxins found in Nature, all antigenically different from each 

 other. Among these are the phytotoxins (plant toxins), ricin, 

 robin, and abrin ; the zootoxins, such as snake venom and scorpion 

 toxin ; and finally the bacterial toxins in which the medical stu- 

 dent is primarily interested. 



True Toxins. — Only a few bacteria are known to produce anti- 

 genic poisons or toxins. The first bacterial toxin discovered was 

 that of C. diphtheriae. This important contribution was made by 

 Roux and Yersin (1888, 1889). Two years later Kitasato (1891) 

 discovered tetanus toxin. Since then, true toxins have been de- 

 scribed for the following bacteria: B. pyocyaneus (Wassermann, 

 1896) ; CI. hotulinum (Kempner, 1897) ; Streptococcus scarlatinae 

 (Moser, 1902; GabritschcAvsky, 1906; Dick and Dick, 1923; Dochez 

 and Sherman, 1924) ; Streptococcus erysipeJatis (Birkhaug, 1925) ; 

 B. dysentcria Shiga (Todd, 1903; Olitsky and Kligler, 1920) ; Vi- 

 hrion septique (Robertson, 1916) ; CI. ivelchii (Bull and Pritchett, 

 1917) and also toxins of some strains of Staphylococcus aureus 

 (Parker, 1924). Perhaps the student can best appreciate the 

 important facts about these various toxins and their respective 

 antitoxins by discussing a few of them separately and also with 

 reference to the particular toxemic disease with Avhieh each is 

 associated. 



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