DIPHTHERIA AND GLANDERS GROUP 387 



the organism in practically pure cultures in smears taken 

 directly from the throat. 



Transmission — Diphtheria is most commonly trans- 

 mitted by the use of common drinking vessels or by passing 

 objects infected in the mouth of one individual to that of 

 another. It is possible that occasionally the disease may be 

 transmitted by the inhalation of infectious droplets. 



Disease carriers (or bacillus carriers so-called) are par- 

 ticularly important in this disease. In any outbreak or 

 epidemic of diphtheria, a considerable proportion of chil- 

 dren and other people who come in contact with diseased 

 individuals may show no symptoms of the disease and yet 

 harbor the organism in the nose or throat. Such individuals 

 can transmit the disease to those who are susceptible quite 

 as readily as those showing serious lesions. Such a diph- 

 theria carrier in a community may readily constitute the 

 starting point of a serious epidemic. 



Genus Ppeifpeeella 



The organisms belonging to the genus Pfeifferella re- 

 semble those of the diphtheria group in that they are 

 slender rods sometimes showing branching, but they are 

 Gram-negative. The most important species of the group 

 is the Pfeifferella mallei, the cause of the disease glanders 

 and farcy in horses and other equines. 



Pfeifferella mallei 



Synonyms. — Bacillus mallei, Bacterium mallei, Myco- 

 hacterium mallei. 



The disease glanders in the horse and other solipeds is 

 widely distributed over the surface of the earth. It is 

 important not only because of the losses occasioned in 

 domestic animals but also because of the danger of trans- 

 mission of the disease to man. 



