

EXPERIMENTAL INOCULATION 297 







Friedmann has recovered from two cases of spontaneous pulmonary tuber- 

 culosis in tortoises a bacillus which, in many of its characteristics, differs 

 from the ichthic bacillus and which appears to be intermediate between the 

 ichthic and human types of tubercle bacilli. Friedmann's bacillus grows 

 both at ordinary room-temperature and at 37 C. : it is not pathogenic to 

 mammals but in the guinea-pig sets up a local lesion which undergoes spon- 

 taneous resolution. 



4. Organisms associated with the tubercle bacillus. 



In tuberculous lesions in man the tubercle bacillus is found frequently associated 

 with various other organisms, the latter being generally of a pyogenic nature. In 

 cavities in the lungs a rich microbial flora is encountered ; the following among 

 other organisms may for instance be found in the lungs in conditions of human 

 pulmonary tuberculous phthisis : staphylococci, streptococci, the pneumobacillus of 

 Friedlander, pneumococci, bacillus pyocyaneus, micrococcus tetragenus, and the 

 bacteria of putrefaction. The hectic fever of patients suffering from tuberculosis 

 is due to the absorption of toxins secreted by these micro-organisms of secondary 

 infection. In glandular and meningeal tuberculosis, etc. it frequently happens 

 that pneumococci, streptococci, and staphylococci are found together with the tubercle 

 bacillus. 



SECTION I. EXPERIMENTAL INOCULATION. 



Guinea-pigs or rabbits are generally inoculated with a pure culture of the 

 bacillus emulsified in a little sterile water [or, better, sterile normal saline 

 solution] or with tuberculous tissues pounded in a mortar with a few drops 

 of water [or saline solution] ; or the material (sputum, pus, small pieces of 

 tissue, etc.) may be introduced directly either beneath the skin or, in the 

 case of tissues, into the peritoneal cavity. 



A. Guinea-pig. 



Guinea-pigs inoculated with material containing even a few tubercle bacilli 

 of mammalian or avian origin invariably become infected with tuberculosis. 



[The high degree of virulence of the avian tubercle bacillus here suggested 

 was not confirmed by the English Commission.] 



Generally speaking, the guinea-pig is less susceptible to avian than to human 

 or bovine tubercle bacilli. According to Weber and Bofinger, the [sub-cutaneous] 

 inoculation of an avian tubercle bacillus leads to a localized infection in guinea- 

 pigs, never to the typical disease. [This opinion is confirmed by the English 

 Commission which finds that "the avian bacillus never produces a progressive 

 tuberculosis in the guinea-pig." ] This conclusion however is not supported by the 

 work of numerous other observers. 



For purposes of description the infection set up by the inoculation of a 

 mammalian tubercle bacillus will be taken as a type. 



1. Sub-cutaneous inoculation. After 10 days or so there appears, at the 

 site of inoculation, a small indurated nodule which later softens and then 

 forms an abscess ; this abscess opens externally leaving an ulcer, the so-called 

 tuberculous chancre. At the same time, the adjacent glands become enlarged, 

 the animal wastes, becomes cachectic and dies in from 1-3 months. Post 

 mortem the most conspicuous lesions are those in the spleen and liver : the 

 spleen is much enlarged, ochre-coloured, speckled with caseous tubercles as 

 well as with more recent yellowish granulations ; the caseous points may 

 have become confluent giving rise to irregular whitish-yellow mammillated 

 masses : the liver shows similar, though, as a rule, less extensive lesions. 

 The surface of the lungs and of the kidneys and the serous membranes will 

 be found covered with a fine sprinkling of miliary granulations. The lym- 

 phatic glands in the neighbourhood of the site of inoculation are caseous. 



