THE BIOLOGICAL ACTIVITIES OF BACTERIA 51 



proved not to be the case, for not only were these bases never toxic 

 in the minute dose sufficient for the true toxins of diphtheria and 

 tetanus, but the anatomical lesions produced were different. More- 

 over, true bacterial toxins seemed to be formed to a great extent 

 independent of the composition of the media upon which growth 

 was obtained, while, as will be seen, ptomaine production depends 

 directly upon the constitution of the substrate. Finally, nothing in 

 the nature of antitoxin production could be shown, following suble- 

 thal injections of the ptomaines. While it is, therefore, not possible 

 to account for the symptoms of bacterial action in the body on the 

 basis of ptomaines, it is not impossible that the ptomaines them- 

 selves, if ingested in food which has undergone some putrefactive 

 changes, may occasionally cause sickness. Food poisoning of this 

 variety was formerly believed to be very common, and was described 

 under various names, as kreatoxismus (meat poisoning) , tyrotoxismus 

 (cheese poisoning) and sitotoxismus (vegetable poisoning). At 

 present there is much question as to whether food poisoning, 

 wherever met with (excepting, of course, botulism, which is caused 

 by the ingestion of a true bacterial toxin), is not caused by the 

 presence of living bacteria of the Gartner type in the food, and not 

 to ptomaines. 5 It is quite possible, on the other hand, that bacteria 

 present in the intestine may, under certain conditions, set up putre- 

 factive changes in the large bowel, leading to the formation of 

 . ptomaines or closely allied substances which can be absorbed directly 

 and cause illness. 



Chemically, the ptomaines are bases produced by the splitting 

 out of C0 2 from the acid group of the amino acids. Amines have 

 been isolated resulting from this form of decomposition of practically 

 all the known amino acids. Of historic interest are putrescine and 

 cadaverine. The former is produced by the decarboxylation of 

 ornithine, thus: 



CH 2 (NH 2 ) CH 2 CH 2 - CH (NH 2 ) COOH = 



CH 2 (NH 2 ) CH 2 CH 2 CH 2 (NH 2 ) +CO 2 



Cadaverine is similarly formed from lysine. Both these bases 

 possess relatively slight toxicity. Much more highly toxic is the 

 base histamine, obtained in an entirely analogous manner from his- 



5 Jordan, "Food Poisoning/' University of Chicago Press, 1917. 



