I02 LABORATORY BACTERIOLOGY 



EXERCISE XLIII 



BACTERIUM DIPHTHERIA 



149. The bacterium of diphtheria is often called the Klebs- 

 Loeffler bacillus. It is the specific cause of diphtheria in man ; 

 but it is not, so far as known, the cause of diphtheria in 

 pigeons and poultry. It is found in the throats of people 

 suffering with diphtheria, and often in the throats and noses 

 of those who have been exposed to it. These are designated 

 as " germ cases." Ordinarily it is not found elsewhere in the 

 body, although it is occasionally discovered in the internal 

 organs and blood. It usually remains in the throat for some 

 days after its lesions have disappeared. Its appearance in the 

 throat lesions is made use of in diagnosing the disease. For 

 this reason it is especially important that its morphology, as 

 well as its cultural characters, should be carefully determined. 

 Although this organism grows on nearly all of the media com- 

 monly used, its development is more rapid and its growth more 

 characteristic on Loeffler's blood serum. The bacterium of 

 diphtheria seems to be modified in its morphology in growing 

 on different media more than any of the other pathogenic bac- 

 teria. Particular attention should be given to its morphology 

 and staining properties. 



References. Chapters on diphtheria in recent editions of 

 text-books. Loetfler, Mitth. aus d. Kais. Gesundheitsamte, Bd. II. 

 Biggs, Park, and Beebe, Scientific Bulletin No. i. Health Dept. 

 City of New York, 1895. Wesbrook (varieties). Jour. Boston 

 Soc. Med. Sciences, Vol. IV, p. 75. Report Am. Pub. Health 

 Asso., 1899, p. 546. Hill (branching forms). Ibid., p. 554. 

 Bergey (pseudo-diphtheria). Publications of the University of 

 Pennsylvania, new series, No. 4, 1898. Smith (toxin). Trans, of 

 the Asso. of Am. Phys., 1896. (Current medical literature con- 

 tains many articles on this subject.) Hill, Report Boston Board 

 "of Health, 1901. 



