DIPHTHERIA GROUP 237 



Loffler, in 1887, found an organism in diphtheritic membranes 

 that resembled the true diphtheria bacillus closely. Hoffman, a 

 little later, made a series of similar observations. These organisms 

 have since been found repeatedly in normal throats, as well as 

 associated with the true diphtheria bacillus in disease. 



Distribution. It has been estimated that about one-sixth of all 

 healthy individuals have the pseudodiphtheria bacilli present in 

 the mouth and throat. 



Morphology. Morphologically, some races have been dis- 

 covered that are practically indistinguishable from the B. diph- 

 theria. In general, however, the pseudodiphtheria organism is 

 somewhat shorter and plumper, and does not ordinarily show 

 granules when treated with the Neisser stain. Some investiga- 

 tors claim to have observed transformations of the one type into 

 the other, but these statements need verification, for other careful 

 workers have failed. 



Pathogenesis. The principal differential character is the lack 

 of pathogenesis and toxin-production by the Hoffman type. 

 Transformation of the non-virulent into the virulent type has not 

 been satisfactorily demonstrated. The organism is of importance 

 only in that it may lead to a mistaken diagnosis of diphtheria. 



