BACILLUS OF TUBERCULOSIS. 3Q5 



fluid. The sedimentation may be obtained more quickly 

 by the centrifugal machine. 



II. Examination for Other Bacteria (Mixed Infection). 



With regard to the bacteriological diagnosis of pul- 

 monary phthisis, many consider that it is not enough 

 to show only the presence of tubercle bacilli; it is held 

 to be of equal importance, both for purposes of prognosis 

 and treatment, that the presence of other micro-organ- 

 isms which may be associated with the tubercle bacillus 

 should also be determined. It is now usual to dis- 

 tinguish pure tuberculosis of the lungs from a mixed 

 infection. Phthisis due to the tubercle bacillus alone, 

 which constitutes but a small percentage of all cases, 

 may occur without febrile reaction; or when fever occurs 

 the prognosis is unfavorable, thus indicating that the 

 disease is already advanced. It is in the uncomplicated 

 forms of phthisis, moreover, where one must expect if 

 anywhere the best results from treatment with tuber- 

 culin or antituberculous serum. The majority of cases, 

 however, of pulmonary tuberculosis show a mixed in- 

 fection, especially with varieties of the streptococcus 

 and pneumococcus. These cases may be active, with 

 fever, or passive, without fever, according, perhaps, 

 as the parenchyma of the lung is invaded by the bac- 

 teria; or they are only superficially located in cavities, 

 bronchi, etc. Mixed infection with the staphylococcus 

 and with the influenza and pneumonia bacilli have 

 also been frequently met with by us. The tetragenus 

 has not been detected by us in thoroughly washed 

 fresh sputum, but has been found by others. At present 

 the facts seem to prove that the tubercle bacilli have 

 in the great majority of cases at least until shortly 



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