THE BACTERIOLOGICAL DIAGNOSIS 

 OF DIPHTHERIA i) 



BY 



Dr. C. W. BROERS. 



Director of the Central Laboratory of Public Health at Utrecht. 



Since more and more attention is being paid to the rôle, 

 played by bacilli-carriers in the epidemiology of diphtheria, 

 the importance of the bacteriological diagnosis of diphtheria has 

 increased, but at the same time, the difficulties attached to it, 

 have become better known. This is the chief reason why the 

 bacteriology of diphtheria has enjoyed universal attention, 

 specially of late. It therefore seemed to me a good idea, to 

 make this subject a point of discussion in the Microbiological 

 Society. 



The first question, that presents itself, of course is, what 

 is a diphtheria bacillus? The answer may be very short, namely, 

 that it is a coryne-bacterium which may cause diphtheria 

 in man. 



The first part of this definition refers to a characteristic 

 namely the appearance of club-shaped, rounded ends, which 

 is typical for a large group of bacteria, to which the diphtheria 

 bacillus also belongs. The second part is not open to experi- 

 mental research. So in making a diagnosis the abovementioned 

 definition does not hold good. 



The diphtheria bacillus has met with the same fate as so 

 many other pathogenic microorganisms ; at first it was thought 

 that the shape only would be enough to classify the microorga- 

 nism, but very soon it got known, that the same morpho- 

 logical characters belonged to many other, also non-pathogenic 



^) Introductory to the discussion of this subject at the meeting of the 

 Microbiological Society held on I5ch of January 1915 (translated by Jeanne S.mit). 



