Bacilli Resembling the Tubercle Bacillus 737 



S. That the designation, "bacillus" as applied to this group of bacteria and to 

 the exciter of tuberculosis is a misnomer; they are more correctly classified as 

 actinomyces. 



The Butter Bacillus 



Petri,* Rabinowitsch,t and KornJ have described, as Bacillus butyricus, an 

 acid-fast organism morphologically like the tubercle bacillus, which may at times 

 be found in butter. Its chief importance lies in the confusion that may arise 

 through mistaking it for the tubercle bacillus where attention is paid to the ihor- 

 phologic and tinctorial characters only, as tubercle bacilli may be found in butter 

 made from cream from the milk of tuberculous cattle. 



Isolation and cultivation of these organisms is easy, and more than any other 

 measure serves to differentiate them from the tubercle bacillus, as they grow upon 

 nearly all the culture-media with rapidity and luxuriance. 





Fig. 288.— Bacillus pseudotuberculosis from agar-agar. X looo ' 

 (Itzerott and Niemann). 



PSEUDOTUBERCULOSIS 



Bacillus Pseudotuberculosis 



Pfeiffer,§ Malassez and Vignal,|| Eberth,** Chaiitemesse,tt Charrm, and 

 RogerJt have all reported cases of so-called pseudotuberculosis occurring m 

 guinea-pigs, and characterized by the formation of cellular nodules in the liver and 

 kidnevs much resembling miliary tubercles. Cultiires made from them showed 

 the presence of a small motile bacillus which could easily be stained by ordinary 

 methods. When introduced subcutaneously into guinea-pigs, the original disease 

 was reproduced. • j l 



Morphology and Cultivation. — Bacillus pseudotuberculosis is characterized by 

 Pf eiffer as follows : The organisms are rod-shaped, the rods varying in length (0.4 

 to 1.2 n) and sometimes united in chains. They may be almost round, and then 

 resemble diplococci. They stain by ordinary methods, but not by Gram's 



* "Arbeiten aus dem kaiselichen Gesundheitsamte," 1897. 



t "Zeitschrift fur Hygiene," etc., 1897. 



t "Centralbl. f. Bakt.," etc., 1899. 



§ "Bacillare tuberculose, u. s. w.," Leipzig, 1889. 



II "Archiv de Physiol, norm. et. Path.," 1883 and 1884. 

 ** " Virchow's Archiv.," Bd. Cii. 

 tt "Ann. de ITnst. Pasteur," 1887. 

 ti"Compte-renduderAcad. des Sci.," Pans, t. cvi. , 



47 



