616 



PATHOGENIC MICROORGANISMS 



Levaditi and Manouelian, 1 the spirochsetes are found not only in the 

 blood but thickly distributed throughout the various organs. 



Under natural conditions, infection of chickens seems to depend 

 upon a species of tick which acts as an intermediate host and causes 

 infection by its bite. The spirochsete, according to Marchoux and Sal- 



imbeni, may be found in the intes- 

 tinal canal of the ticks for as long 

 as five months after their infection 

 from a diseased fowl. 



In the blood of animals which 

 have survived an infection, agglutin- 

 ating substances appear and active 

 immunization of animals may be 

 carried out by the injection of in- 

 fected blood in which the spirochsetes 

 have been killed, either by moderate 

 heat or by preservation at room 

 temperature. The serum of immune 

 animals, furthermore, has a pro- 

 tective action upon other birds. 



It is not impossible that the Spiro- 

 chseta gallinarum may be identical 

 with the Spirochseta anserina previ- 

 ously discovered by Sacharoff. 2 This 



last-named microorganism causes a disease in geese, observed espe- 

 cially in Russia and Northern Africa, which both clinically and in its 

 pathological lesions corresponds closely to the disease above described 

 as occurring in chickens. The spirochsete is found during the febrile 

 period of the disease in the circulating blood, is morphologically indis- 

 tinguishable from the spirochsete of chickens, and can not be cultivated 

 artificially. The similarity is further strengthened by the fact that 

 Spirochseta anserina is pathogenic for other birds, but not for animals 

 of other genera. Noguchi has succeeded in cultivating Spirochseta 

 gallinarum by the same method by which he has cultivated the or- 

 ganisms of relapsing fever. Ascitic fluid tubes with a piece of sterile 

 rabbit kidney were inoculated with a few drops of blood containing the 

 spirochsetes and cultivated at 37.5 C. under anaerobic conditions. 

 Spirochseta phagedenis. This is an organism cultivated by Noguchi 



1 Levaditi et Manouelian, Ann. de Tinst. Pasteur, 1906. 



2 Sacharoff, Ann. de Tinst. Pasteur, 1891. 



FIG. 138. SPIROCHSETA GALLINA- 

 RUM . (From preparation furnished 

 by Dr. G. N. Calkins.) 



