CHAPTER XXX 



DIPHTHEEIA AND GLANDERS GROUP THE GENERA 

 CORYNEBACTERIUM AND PFEIFFERELLA 



CORYNEBACTERIUM 



THE bacteria belonging to the genus Cory neb act erium are 

 rods, Gram-positive, nonmotile, aerobic and facultative, not 

 producing spores and characterized by the possession of 

 metachromatic granules. They may also show marked 

 tendency to the development of threads and more or less 

 irregular branching and club forms. The most important 

 organism belonging to the group is the Coryneb act erium 

 diphtherice, the cause of the disease diphtheria. Another 

 organism, the C or ynebact erium pseudotuberculosis, has been 

 found to produce a considerable variety of infections in 

 domestic animals, the organism in sheep giving rise to the 

 formation of enlarged lymph glands and producing some- 

 what similar diseases in cattle, horses, rabbits and other 

 animals. In addition there have been described a consider- 

 able number of organisms belonging to this group, associated 

 with other diseases in man but not definitely proved 

 to have a causal relationship to them. Bacteria belonging 

 to this group furthermore have been isolated repeatedly 

 from the throat and mouths of healthy individuals. The 

 only species which will be discussed is the organism causing 

 diphtheria. 



CORYNEBACTERIUM DIPHTHERIA 



Synonyms. Bacillus diphtherice, Bacterium diphtherice, 

 Mycobacterium diphtherice. 



This organism is the specific cause of the disease diph- 



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