82 STUDY AND IDENTIFICATION OF BACTERIA 



tical purposes, enables us to eliminate the smegma and similar bacilli, 

 these being decolorized by such treatment. There are two objections 

 to the Gabbett method, where decolorizer and counterstain are combined : 

 i. We cannot judge of the degree of decolorization we are working 

 in the dark; and 2. the matter of elimination of smegma bacilli is 

 impossible. 



Pappenheim's method, in which corallin and methylene blue are dissolved in 

 alcohol, does not appear to have an advantage over acid alcohol. As a practical 

 point when the question of tuberculosis of the genito-urinary tract is involved, 

 inoculate a guinea-pig with urinary sediment. 



It must be remembered that in young cultures of tubercle bacilli many of the 

 rods are nonacid-fast, taking the blue of the counterstain, while older rods are acid- 

 fast. This frequently causes suspicion of a contaminated culture. 



Discussion has arisen as to the granules of Much. These are considered by Much 

 as resistant forms while others consider them degeneration forms of tubercle 

 bacilli. At any rate material containing only these Gram positive granules and no 

 acid-fast rods may when injected into animals give rise to tuberculosis and acid- 

 fast bacilli. 



The combination of the acid-fast and Gram staining methods as recommended 

 by Fontes is very satisfactory. 



Bacillus Leprae (Hansen, 1874). This is the cause of leprosy. In 

 nodular leprosy the organism is readily and in the greatest abundance 

 found in the juice of the tubercles of the skin, and secretions of 

 ulcerations of nasal and pharyngeal mucosa. 



The earliest lesion is probably a nasal ulcer at the junction of the bony and 

 cartilaginous septum. Scrapings from this ulcer may give an early diagnosis. 



In the skin they are chiefly found in the derma packed in the so-called lepra 

 cells. The process is granulomatous but does not show the caseation of tubercu- 

 losis or the predominant plasma cells of syphilis. The bacilli are also found engulfed 

 in the endothelial cells lining the lymphatics. 



They are also found in the glands in relation to the superficial lesions. The 

 bacilli are found in smaller numbers in the liver and spleen. In anaesthetic or nerve 

 leprosy they are found in small numbers in the granuloma tissue which affects the 

 interstitial connective tissue of the peripheral nerves. Also, rarely, in the anaesthetic 

 spots of nerve leprosy. 



In morphology and staining reactions they are almost identical 

 with the tubercle bacillus. The main points of distinction are : i. The 

 fact of the leprosy bacilli being found in enormous numbers, especially 

 in large vacuolated cells (lepra cells), and lying in the lymph spaces. 

 They are frequently beaded and lie in masses which have been likened 

 to a bundle of cigars tied together, so that smears show the bacilli in 



