254 



TUBERCULOSIS 



from Rabinowitch's bacillus. The points of distinction are of a minor 

 character. Other more or less similar bacilli have been cultivated by 

 Tobler, Coggi, and others. 1 



Another bacillus of considerable interest is Johne's bacillus or the 

 bacillus of "chronic bovine pseudo-tuberculous enteritis," the lesions 

 produced by it being corrugated thickenings of the mucous membrane, 

 especially of the small intestine. The disease has now been observed in 

 various countries, and several cases in Britain have been recorded by 

 M'Fadyean. The bacilli occur in large numbers in the lesions, and can 

 readily be found in scrapings from the surface. They resemble the 



tubercle bacillus in appear- 

 ance, but on the whole are 

 rather shorter ; they are 

 equally acid-fast. The organ- 

 ism has not yet been culti- 

 vated outside the body. 



Smegma Bacillus. This 

 organism is of importance, 

 as in form and staining re- 

 action it somewhat resembles 

 the tubercle bacillus and may 

 be mistaken for it. It occurs 

 often in large numbers in 

 the smegma prseputiale and 

 in the region of the external 

 genitals, especially where 

 there is an accumulation of 

 fatty matter from the secre- 

 tions. Morphologically it is 

 a slender slightly curved 

 organism, like the tubercle 

 bacillus but usually dis- 

 tinctly shorter (Fig. 90). 

 Like the tubercle bacillus it 

 stains with some difficulty 



and resists decolorisation with strong mineral acids. Most observers 

 ascribe the latter fact to the fatty matter with which it is surrounded, 

 and find that if the specimen is treated with alcohol the organism is 

 easily decolorised. Czaplewski, however, who claims to have cultivated 

 it on various media, finds that in culture it shows resistance to decolor- 

 isation both with alcohol and with acids, and considers, therefore, that 

 the reaction is not due to the surrounding fatty medium. We have 

 found that in smegma it can be readily decolorised by a minute's exposure 

 to alcohol after the usual treatment with sulphuric acid, and thus can 

 be readily distinguished from the tubercle bacillus. We, moreover, 

 believe that minor points of difference in the microscopic appearances of 

 the two organisms are quite sufficient to make the experienced observer 

 suspicious if he .should meet with the smegma bacillus in urine, and lead 

 him to apply the decolorising test. Difficulty will only occur when a few 

 scattered bacilli retaining the fuchsin occur. 



Its cultivation, which is attended with some difficulty, was first 



1 For further details on this subject, vide Potet, Etudes sur les bacilles dites 

 acidophiles. Paris, 1902. 



FIG. 90. Smegma bacilli. Film preparation 



of smegma. 

 Ziehl-Neelsen stain. x 1000. 



