DIPHTHERIA BACILLUS 2OQ 



lived on culture media for eighteen months at room temperature; 

 also in silk threads for several months in a dried condition. 

 Remains alive in healthy throats for months. Formalin vapor 

 kills it speedily; corrosive sublimate solution, i- 10,000, destroys 

 it in a few minutes; light is lethal to it in from two to ten hours, 

 and heat at 58C. in ten minutes. 



Habitat. It has not been found in sewage, or sewer gas, soil 

 or water, the disease therefore is never transmitted by these means. 



FIG. 63. Diphtheria bacilli involution forms. (Kolle and Wassermann.) 



Has been found in the throat, nose, and in the conjunctivas of 

 healthy bodies. In disease, the organism is mostly found in the 

 throat, but has been isolated from all the organs in some fatal 

 cases. Sometimes it is discovered in the throats of animals. 

 Though its action is local, it elaborates a toxin which acts 

 systematically. 



Cultures. On gelatine plate the growth is scanty and raised. 

 This medium is never for cultivating this organism. The 

 gelatine is not liquefied. On glycerine agar plates the growth, 

 though moderate, is typically characteristic, but very slightly 



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