KOCH'S POSTULATES 2Q 



Koch's Postulates. 



In order to prove that a certain organism is the infectious agent 

 of a given disease, Koch has devised four postulates which the given 

 organism must fulfill before it can be considered the cause of the 

 disease. 



1. The organism must be found microscopically in the tissues 

 of the animal having the disease, and its position in the lesion should 

 explain the latter. 



2. It must be isolated in pure state from bodies of the diseased 

 animals. 



3. And then it must be grown for successive generations in cul- 

 ture media. 



4. If injected into a healthy animal, or animals, it must produce 

 the same disease, and be found in the lesions of the disease in the 

 animal's tissues, ^/ 



Some of the many organisms that certainly fulfil these conditions, 

 are as follows: 



Streptococcus Pyo genes (Sepsis) . A ctinomyces. 



B. of Tuberculosis. B. of Diphtheria. 



B. of Anthrax. B. of Tetanus. 



B. of Glanders. B. of Malignant Oedema. 



B. of Bubonic Plague. B. of Malta Fever. 



B. of Typhoid. B. of Dysentery. 



Spirillum cholera. Meningococcus. 



Pneumococcus (Pneumonia). B. of Leprosy. 



Spirochata of Relapsing Fever and of Syphilis. 

 There are several other organisms that are considered to be the 

 cause of specific disease, but they do not fulfil the postulates. 

 Among these are: 



The Organism of Scarlet Fever (Protozoans). 



The Protozoa of Malarial Fever. 



Amoeba Dysenteric. 



