346 THE PARA-TUBERCLE BACILLI 



Borrel their morphological characteristic as in the case of the tubercle bacillus is 

 to remain a bright red colour when treated in the following manner 



1. Stain with carbol-fuchsin in the warm for 5 or 10 minutes. 



2. Treat with 2 per cent, aniline hydrochloride for 1 or 2 minutes. 



3. Decolourize in absolute alcohol. 



4. Differentiate with a dilute aqueous solution of methylene blue. 



They are distinguished from the tubercle bacillus, (1) by the ease with which they 

 can be grown on various media containing no glycerin at the ordinary temperature 

 of the laboratory (2) by their cultural characteristics (luxuriant and generally 

 greasy and creamy) and (3) finally and especially, by the fact that they do not produce 

 tuberculin. Ramond and Ravaut, Bataillon and Terre have described an ichthic 

 tuberculin similar to human tuberculin but their results have not been confirmed 

 (p. 296). 



Some of the members of this group are pathogenic to animals, particularly guinea- 

 pigs, and may set up either local lesions distinctly tuberculous in appearance 

 or pseudo-miliary- tuberculoses (Timothee bazillus) which have a tendency to 

 suppurate. 



Finally, several authors have directed attention to the existence of pseudo-acid- 

 fast bacilli (Bezangon and Philibert, Bienstock, and others). A large number of 

 saprophytic bacilli as a result of living in contact with fatty substances acquire, 

 accidentally, as it were, acid-fast properties (e.g. B. smegmce] which are lost as soon 

 as they are grown on ordinary culture media. Other saprophytic bacilli become 

 acid-fast when grown in blood or sero-fibrinous exudates (Bezancon and Philibert). 

 The Bacillus anthracis, Bacillus subtilis (Bienstock), Bacillus entericce febris (Ramond 

 and Ravaut), and Bacillus diphtherice (Bezan9on and Philibert) become acid-fast 

 when grown in media containing butter. But all these pseudo-acid-fast bacilli are 

 decolourized by prolonged treatment with acid and especially by alcohol (pp. 306 and 

 342) ; and moreover, unlike the tubercle bacillus, they can be stained with Unna's 

 blue (10 minutes). 



There should therefore be no reason for confusing the tubercle bacillus with the 

 para-tubercle bacilli. 



The smegma bacillus. 



Tavel, Alvarez, Matterstock have isolated from normal smegma a bacillus which 

 resists decolourization by acids. This is the bacillus which Lustgarten described as 

 the cause of syphilis. It has not been grown outside the body and is decolourized 

 by acid-alcohol ; it should not therefore be difficult to differentiate it from the 

 tubercle bacillus. Houssell's method is the best for purposes of micro-chemical 

 diagnosis. The technique is as follows. 



Stain the film in the warm for 2 minutes with carbol-fuchsin. Wash. Treat 

 for 10 minutes with acid-alcohol. 



Absolute alcohol, - - - 100 c.c. 



Pure hydrochloric acid, - 3 



Wash again. Stain with an aqueous solution of methylene blue. 



Saturated aqueous solution of methylene blue, - 50 c.c. 



Distilled water, 50 



Wash. Dry. Mount. The smegma bacillus will be stained blue, the tubercle 

 bacillus, red. 



The bacillus of verruga peruana. 



Verruga is a disease found in certain valleys of the Andes. It affects man and 

 some of the domestic animals. It occurs both as an acute and chronic disease and 

 leads to the formation of granulomata on mucous surfaces, the skin and the viscera 

 (Odriozola). Carriou inoculated himself with the blood of a person suffering from 

 the chronic form of the disease and died of an acute infection. A dog, inoculated 

 by Tamayo with 1 c.c. of the blood of a person suffering from verruga in an acute 

 form, became infected with a typical attack of the disease and recovered. According 

 to Ch. Nicolle and Letulle, the cause of verruga is a bacillus morphologically identical 

 with the tubercle bacillus and staining by the Ziehl-Neelsen method. The organism 

 has not been cultivated. 





