CHAPTER IX 



UDDER-PYOBACILLOSIS 



Infectious Organism 



The infectious organism is the pyogenes bacillus, ba- 

 cillus pyogenes. 



Characteristics. — The bacillus pyogenes is a very 

 small thin bacillus. It stains slowly and faintly with the 

 common anilin dyes but stains well after the method of 

 Gram. Its growth on the usual culture media is thin, 

 especially the surface growths. It liquefies coagulated 

 serum and gelatin after a somewhat longer time. It coagu- 

 lates milk. The organism is found in Germany, Holland, 

 Denmark and Sweden. This indicates that it is of wider 

 distribution, although it has not been reported since it was 

 briefly studied by Grips, Glage and Nieberles. It can be 

 found here and there in the various districts of Sweden. 



It appears to be present frequently in the digestive 

 tract of cattle since it is often found in diseased nodules 

 produced by foreign bodies in the reticulum. One may 

 therefore assume that it is to be found in the dirt and dust 

 of our cow stables. 



Morphology. — The bacillus pyogenes is a small and 

 very fine rod. Its size varies somewhat. It is 1 to 3 microns 

 long and 0.2 to 0.3 micron thick. As a rule, the bacillus 

 is 2.5 microns long and 0.2 micron thick. In dimensions 

 it most closely resembles the erysipelas bacillus and also 

 the tubercle bacillus, except that the latter is a little larger. 



The bacillus pyogenes is usually rod-shaped. Only in 

 cultures, especially on coagulated serum, does the organism 

 assume an oval or nearly round shape in consequence of 

 rapid multiplication. 



This organism usually appears singly in smear prepara- 



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