342 SPECIFIC MICRO-ORGANISMS 



Bacillus Sxxipestifer (B. Salmonii). — This organism occurs in 

 the intestinal contents of hogs and in the blood in the late stages 

 of hog cholera, and was for a time believed to be the cause of this 

 disease. More recent studies indicate that the etiological factor 

 is a filterable virus (See page ^92.) B. suipestifer resembles B. 

 enteritidis yeiy closely. 



Bacillus Icteroides was described by Sanarelli in 1897 as the 

 cause of yellow fever, a disease now known to be due to a different 

 organism (page 374). It cannot be specifically distinguished 

 from B. suipestifer. 



Bacillus Psittacosis was found by Nocard in 1892 to be the 

 cause of an epidemic pneumonia transmitted to man from dis- 

 eased parrots. It resembles B. coli but may be distinguished by 

 inoculating parrots, for which it is extremely virulent. 



BaciUus Typhi Murium. — ^Loffler in 1890 found this organism 

 to be the cause of a fatal epizootic among laboratory mice. It 

 forms gas and acid from dextrose, does not produce indol nor co- 

 agulate milk. Mice are very susceptible and the organism has 

 been employed as a practical means of destroying mice. It seems, 

 however, not to be altogether harmless for larger animals and for 

 man, and it is believed that some of the paratyphoid fever fol- 

 lowing food poisoning in man has been due to this particular 

 ofganism. 



Bacillus (Faecalis) Alkaligenes. — This organism is occasionally 

 found in human feces and is of importance because of the possi- 

 bility of mistaking it for the t}^hoid bacillus, which it resembles 

 in most respects. It does not produce acid from any of the sugars 

 nor is it agglutinated by typhoid serum. It is not known to 

 cause disease. 



Bacillus Paratyphosus. — In certain irregular fevers in man 

 resembling typhoid fever there have been found bacteria somewhat 

 intermediate in character between B. coli and B. typhosus. These 

 have sometimes been cultured from the blood stream; at other 

 times from the feces. The presence of specific agglutinins in the 

 patient's blood is further evidence of the pathogenic relationship 



