BACTERIOLOG1C DIAGNOSIS. 277 



diagnosis in typhoid fever, as the bacilli make their way into 

 this organ very early in the disease. The dangers connected 

 with such a procedure are manifest, and prohibit the encour- 

 agement of any such method as a routine practice by the 

 average practitioner. 



In a very few instances the bacillus has been found in the 

 sweat; and in the sputum and the mucus obtained from the 

 throat. In typhoidal pneumonia that is, a pneumonia due 

 to the typhoid bacillus this organism is constant in the 

 sputum. 



Mixed and secondary infection : Typhoid fever is rarely a 

 pure infection. Bacillus typhosus is most frequently asso- 

 ciated with Bacterium coli communis and the streptococcus 

 pyogenes. The colon bacillus is held responsible for most of 

 the complications of typhoid fever, such as peritonitis, chol- 

 angitis, etc. The streptococcus is the cause of otitis media, 

 bronchopneumonia, and empyerna. The severe prostration, 

 resembling sepsis, occasionally seen in aggravated cases of 

 this disease is invariably due to a mixed or secondary infec- 

 tion with the streptococcus. Staphylococci and diplococci, 

 especially the pneumococcus, are occasionally associated with 

 the typhoid bacillus. Nearly all the pulmonary complica- 

 tions, however, are due to either the streptococcus or Bacillus 

 typhosus. The pneumococcus causes the secondary pneu- 

 monia, but not the complicating pneumonia. 



Bacteriologic diagnosis : The close resemblance of the 

 typhoid bacillus to the colon bacillus makes its diagnosis a 

 matter of some difficulty. In fact, it can only be done by 

 cultivating the organism and noting the cultural differences 

 between the two. The bacillus is obtained from the feces, 

 urine, blood, etc., and examined microscopically. The 

 typhoid bacillus is more motile and has more flagella than the 

 colon bacillus, but such differences are not very reliable. 

 These two germs also stain alike. Their cultures are alike 

 except on potato, on which the typhoid forms an invisible 

 growth ; and the colon bacillus a heavy brownish membrane 

 with slight greenish discoloration of the potato. 



Additional points of differentiation are the following : 



