108 STUDY AND IDENTIFICATION OF BACTERIA 



authorities believe it possible for these diphtheroids to be capable of 

 being transformed into virulent diphtheria bacilli. This seems im- 

 probable. Such organisms are often found in urethral discharges, 

 either alone, or with gonococci or other organisms. 



Recently a great deal of attention has been given to the etiological relationship 

 between diphtheroids and Hodgkin's disease. Fox, in a critical study of this 

 relationship, has obtained diphtheroids of varying morphology and cultural charac- 

 teristics from such glands as well as from enlarged glands of chronic atrophic arthritis 

 and other conditions. It would appear conservative to reject the acceptance of 

 diphtheroids as causative agents not only in this disease but in leprosy as well. 



Negri has applied the name Coryne bacterium granulatis malignl to diphtheroids 

 isolated from glands in Hodgkin's disease. The granular rods of Much, supposed 

 to be connected with tubercle bacilli, may be diphtheroids. Mallory has connected 

 diphtheroids with scarlet fever. 



DIPHTHEROID CHARACTERISTICS 



1. They very rarely give the blue dot staining at the two ends. Exceptionally 

 they may give a dot at one end. Neisser attaches importance to the dots at both 

 ends as showing diphtheria. 



2. They tend to stain solidly or at most with only a single unstained segment. 

 They are shorter, thicker, and do not curve so gracefully as the true diphtheria 

 bacillus. They are stockier. 



3. They produce very little acid in sugar media, not one-half that produced by 

 true diphtheria. Goldberger found 29 out of 30 cultures of B. diphtheria virulent 

 and acid producers. Of 47 Hofmann cultures 6 showed slight acid production while 

 41 produced alkali. All were nonvirulent. 



4. They are nonpathogenic for guinea-pigs. 



5. Many of them grow quite luxuriantly and often show chromogenic power. 



Xerosis Bacillus. This organism is frequently found in normal con- 

 junctival discharges. There is question as to its pathogenesis, and the 

 finding of this organism should not exclude the previous presence of 

 strictly pathogenic organisms, such as the Gonococcus or the Koch- 

 Weeks. It resembles the diphtheria bacillus in being Gram-positive 

 and showing parallelism, but differs i. in being nonvirulent for guinea- 

 pigs; 2. in requiring about two days for the appearance of colonies; 3. 

 in not showing Neisser's granule staining, and 4. in producing very 

 little acid in sugar media. 



