A CI D- FA ST BA CILLI IN B UTTER 2 5 5 



these organisms were bacilli, but they showed much variation in 

 form and polymorphism, some appearing to be like B. diphtheria, 

 and others like actinomyces. The staining properties were, in all 

 cases, those of the true bacillus of Koch, except that the power of 

 resistance to decoloration by acid was rather less.^ We have 

 cultured many of these organisms upon different media and have 

 found them to show various modifications in form, chromogenicity, 

 vitality, polymorphism, etc. (Plate 22, between pp. 234 and 235, 

 from a series of photographs of cultures, shows the various characters 

 often of these acid-fast species compared with the human and bovine 

 tubercle bacillus, all the cultures having been grown on the same 

 media, for approximately the same length of time, under precisely 

 the same conditions. The illustrations are of the exact size of the 

 cultures, which were in each case composed of one colony only.) 

 These acid-fast bacilli live and develop on all ordinary media at 

 room temperature and blood heat, preferably under aerobic condi- 

 tions. They do not form indol or liquefy gelatine, nor do they 

 possess much pathogenic action. Whilst the acid-fast bacilli found 

 in milk and butter are described in detail in a subsequent chapter, 

 a few general notes may be made here respecting the type, 

 namely, the organism obtained from butter by Rabinowitsch. 



The butter bacillus of Petri- Rabinowitsch. — Morphologically, this 

 organism is like the ordinary tubercle bacillus, though somewhat 

 shorter and thicker. It stains in the same manner, but grows 

 readily at room temperature and rapidly at blood-heat The 

 cultures appear as moist, thick, creamy, wrinkled layers of growth 

 on the surface of the medium. The organism possessed less viru- 

 lence when inoculated in pure culture. But when inoculated with, 

 or without, butter, it has clearly defined effects. Giant cells, nests 

 of epithelioid cells, and typical tuberculous caseation are, according 

 to Rabinowitsch, never to be found in the foci of disease set up 

 by this bacillus. None of the animals injected with this bacillus 

 reacted to tuberculin. The intraperitoneal injection of pure cul- 

 tures often produces a formation of nodules in the abdominal 

 organs which frequently heal. If, however, the animals are killed 

 in three or four weeks, the following characteristics are found, 

 namely, slightly distended abdomen, more or less severe perito- 

 nitis, nodules on mesentery and beneath the intestinal serosa, 

 mesenteric glands enlarged, and liver, spleen, and kidneys show- 

 ing small nodules with yellowish exudation. When the butter 

 itself containing the organisms is used, a fatal result often follows 

 ^ Report of Medical Officer of Local Government Board, 1 900-1, pp. 331-3. 



