Bacilli Resembling the Tubercle Bacillus 693 



Moeller's Grass Bacillus 



Bacilli found in milk, butter, timothy hay, cow-dung, etc., which stain like the 

 tubercle bacillus and may be mistaken for it, have been described by Moeller.* 

 The organisms so closely resemble the tubercle bacillus that guinea-pig inocu- 

 lations must be resorted to in cases of doubt, but as some of these organisms 

 sometimes kill the guinea-pigs after a month or two, and as small nodules or 

 tubercles may be present in the mesentery, peritoneum, liver, lung, etc., of such 

 animals, the diagnosis may have to be subjected to the further confirmation of a 

 histologic examination of the lesions in order to exclude tuberculosis. In cases of 

 this kind it should not be forgotten that the tubercle bacillus can be present in the 

 substances mentioned, so that the exact differentiation becomes a very fine one. 

 An instructive study of these organisms has been made by Abbott and Gilder- 

 sleeve,! who, in an elaborate work upon the "Etiological Significance of the 

 Acid-resisting Group of Bacteria, and the Evidence in Favor of Their Botanical 

 Relation to Bacillus Tuberculosis," a work that gives complete references to the 

 literature of the subject, come to the following conclusions: 



1. That the majority of the acid-resisting bacteria may be distinguished from 

 true tubercle bacilli by their inability to resist decolorization by a 30 per cent, 

 solution of nitric acid in water. 



2. That some of the acid-resisting bacteria are capable of causing in rabbits and 

 guinea-pigs nodular lesions suggestive of tubercles; that these lesions, while often 

 very much like tubercles in their histologic structure, may nevertheless usually be 

 distinguished from them by the following peculiarities: 



(a) When occurring as a result of intravenous inoculation, they are always 

 seen in the kidneys, only occasionally in the lungs, and practically not at all in 

 the other organs. 



(6) They constitute a localized lesion, having no tendency to dissemination, 

 metastasis, or progressive destruction of tissue by caseation. 



(c) They tend to terminate in suppuration or organization rather than in pro- 

 gressive caseation, as is the case with true tubercles. 



(d) They are more commonly and conspicuously marked by the actinomyces 

 type of development of the organisms than is the case with true tubercles, and 

 these actinomycetes are less resistant to decolorization by strong acid solutions 

 than are those occasionally seen in tubercles. 



3. That by subcutaneous, intravenous, and intrapulmonary inoculation of 

 hogs (4) and calves (15) the typical members of the acid-resisting group are 

 incapable of causing lesions in any way suggestive of those resulting from similar 

 inoculations of the same animals with true tubercle bacilli. 



4. That though occasionally present in dairy products, they are to be regarded 

 as of no significance, etiologically speaking, but may be considered as accidental 

 contaminations from the surroundings, and not as evidence of disease in the 

 animals. 



5. 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,§ and Korn|| have described, as Bacillus butyricus,an 

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

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

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

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

 made from cream from the milk of tuberculous cattle. 



* "Deutsche med Zeitung," 1898, p. 135; "Deutsche med. Wochenschrift," 

 1898, p. 376, etc. 

 t "Univ. of Penna. Bulletin," June, 1902. 



I "Arbeiten aus dem Kaiselichen Gesundheitsamte," 1897. 

 § "Zeitschrift flir Hygiene," etc., 1897. 



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



