CHAPTER XXIV. 



LEPROSY AND ACID-FAST BACTERIA OTHER THAN 

 THE TUBERCLE GROUP. 



THE BACILLUS LEPRJS. 

 Leprosy of Rats. 



ACID-FAST BACILLI OTHER THAN BA- 

 CILLUS TUBERCULOSIS AND BACILLUS 

 LEPR^E. 



The Smegma Bacillus. 



The Nasal Secretion Bacillus. 



Bacillus Phlei. 



The Butter Bacillus. 



THE BACILLUS LEPR^l. 



THE first definite observation of the organism now called Bacillus 

 leprse was that of Hansen, 1 who described rod-shaped organisms in 

 leprous tissue. Somewhat later Neisser 2 succeeded in staining them. 

 Sticker 3 made the important discovery that the nasal mucosa and 

 nasal secretion of a large percentage of lepers (140 out of a total of 

 153 cases examined) contain large numbers of leprosy bacilli. The 

 organism described by Hansen is generally accepted as the causative 

 agent of leprosy. 



Morphology. Morphologically Bacillus leprse resembles Bacillus 

 tuberculosis. It is a slender, rod-shaped organism, measuring from 

 4 to 6 microns in length. Usually it is somewhat shorter than the 

 tubercle bacillus, curved forms are less common, and the ends of the 

 bacilli are not infrequently somewhat enlarged. They occur charac- 

 teristically as clusters of bacilli, grouped together in bundles like 

 cigars, lying within large cells the so-called lepra cells. The organisms 

 from young lepra nodules are more acid-fast than the tubercle bacillus; 

 in old, degenerating nodules they tend to lose their acid-fastness and 

 other staining properties, and the cytoplasm becomes vacuolated, 

 giving the bacilli a beaded appearance. Bacillus leprse is Gram-positive 

 as well as acid-fast. Available evidence indicates that the organism 

 is non-motile, possesses no flagella, and forms no capsules. 



1 Virchow's Arch., 1880, Ixxix, 32. 



2 Ibid., 1881, Ixxxiv, 514. 



3 Berl. klin. Wchnschr., 1897, 518; Arb. a. d. kais. Gesamte, 1899, xvi, 357. 



