DIAGNOSIS OF DIPHTHERIA 347 



the others having no relation with this organism. The 

 Klebs-Loffler-like avirulent bacilli might, therefore, be 

 regarded as true diphtheria bacilli slightly removed from 

 virulence, the Hofmann bacillus, if derived from the 

 Klebs-Lofner, as a diphtheria bacillus far removed from 

 virulence. 



In determining the fermentation reactions of the diphtheria- 

 like bacilli, the organisms should first be grown in broth until they 

 become acclimatised to this medium, or should be grown in a 

 medium which suits them, e.g. broth with the addition of serum or 

 of ascitic fluid. Hiss's serum-water medium is satisfactory serum 

 1 part, water 3 parts, with 1 per cent, of carbohydrate or other 

 substance, tinged with litmus and sterilised in the steamer on three 

 consecutive days. Graham-Smith 1 gives the following table of 

 fermentation tests (see p. 348). 



Hine 2 remarks that he has yet to find an organism of 

 the diphtheria group, giving acid with glucose and dextrin 

 but not with saccharose, which proves to be other than 

 the B. diphtheria*. 



Clinical Diagnosis 



(A) In man and animals : I. In some cases the diphtheria 

 bacillus can be identified in the membrane or discharge, and the 

 diagnosis established thereby. 



Films are made with the exudation, or with a fragment of the 

 membrane teased up as finely as possible on a slide, a droplet of 

 water being added if necessary. One of these films should be 

 stained with Loffler's methylene blue, another by Gram's method. 

 The bacilli will be found lying parallel to one another in larger or 

 smaller groups, together with involution forms. Films stained 

 with Neisser's or Pugh's stain (see below) may also be of assist- 

 ance. Another method is to stain the films for five seconds in 

 dilute carbol-methylene blue (7 drops to 10 c.c. water), rinsing and 

 drying, and counter-staining in dilute carbon -fuchsin (10 drops to 

 10 c.c. water) for one minute, rinsing and drying (Higley). 



1 Journ. of Hygiene, vol. vi, 1906, p. 286. 



2 Journ. Path, and Bacter., vol. xviii, 1913, p. 75. 



