CHAPTER LVII 

 SUBLETHAL INTOXICATIONS WITH BACTERIAL PRODUCTS 



J. P. SIMONDS 



Northwestern University Medical School 



Sublethal intoxications may result either from a small dose of a powerful bacterial 

 poison which in larger amount would cause the death of the animal, or from the action 

 of bacterial products of relatively low toxicity. In general, sublethal intoxications 

 differ from lethal forms quantitatively rather than qualitatively, in intensity rather 

 than in kind. 



Sublethal intoxications may be induced experimentally or occur spontaneously. 

 Experimental intoxications are produced for the purpose of studying the early stages 

 of the diseases for which they are responsible, and in order that, under accurately 

 controlled conditions, the effects of the toxins may be differentiated from those of 

 extraneous causes which under uncontrolled conditions cannot be accurately deter- 

 mined. Spontaneous sublethal intoxications with bacterial products occur in infec- 

 tious diseases from which the animal or man recovers. Many of the effects of infectious 

 diseases are believed to be due to the action of toxic products of the infecting micro- 

 organism and not to the physical effects of the bacteria themselves, (i) Some effects 

 are general, involving the entire body, such as changes in temperature and metabo- 

 lism. (2) Degenerative changes occur in parenchymatous organs far removed from 

 the actual location of the growing bacteria. (3) Many of the lesions characteristic 

 of infectious diseases differ from those in which bacteria are known to be actually 

 present in the tissues. It has been tersely remarked by Courmont and Rochaix that 

 "the microbe is above all a fabricator of toxins; the infectious disease is an intoxica- 

 tion."^ 



Toxic bacterial products are of three general types: (i) basic substances resulting 

 from the action of bacteria upon various kinds of organic matter, the ptomaines of 

 Brieger;^ (2) true soluble toxins, definite metabolic products of the micro-organisms, 

 found in the medium in which the bacteria are growing; (3) and toxic substances, 

 the endotoxins, firmly fixed in the bacterial cell and liberated upon disintegration of 

 those cells. 



The ptomaines are not true bacterial toxins in that they are not specific products 

 of bacterial metabolism and do not induce the formation of antibodies when injected 

 into animals. Many diseases formerly believed to be due to poisoning with ptomaines 

 are now known to be actual infections.-' 



The soluble toxins require an incubation period for their effects to become mani- 



■ Courmont, J., and Rochaix, A., in Bouchard, Ch., and Roger, G.-IL: Pathologic gemrale, 

 chap, ii, p. 1074. Paris, 1914. 



^Brieger, L.: Die Ptomaine. Berlin, 1885. 

 3 Jordan, E. O.: Food Poisoning. Chicago, 1917. 



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