278 VETERINARY BACTERIOLOGY 



the specific organism in several outbreaks of the disease from the 

 internal organs, particularly the livers, of chicks that had died 

 of the disease or were showing symptoms. He also isolated it 

 from abnormal egg-yolks in the ovaries of hens, from freshly laid 

 eggs, and from the yolk-sacs of fully developed chicks within the 

 shell. He also succeeded in infecting chicks by feeding, but the 

 disease was not always contracted. Subcutaneous injections 

 always proved fatal. Hadley, Kirkpatrick, and others have been 

 unsuccessful in transferring the disease by feeding. 



Characteristics of Disease and Lesions. The most noticeable 

 antemortem characteristics are emaciation and wasting of the chick, 

 and the white diarrhea. The lesions are confined principally to 

 the intestines, and particularly the cecum. The liver is some- 

 times congested in areas. 



Immunity. Practicable methods of immunization have not 

 been evolved. 



Bacteriologic Diagnosis. The organism may be isolated in 

 pure culture from the internal organs, particularly the liver. 

 Work on the normal intestinal flora of the chicken is needed. 



Transmission and Prophylaxis. Rettger claims that the dis- 

 ease is sometimes present before hatching, the organism being 

 present in the ovaries and oviduct, and that contamination of the 

 food likewise results in infection. 



SUBGROUP m TYPHOID-DYSENTERY SUBGROUP 



The three important organisms belonging to this subgroup 

 Bacillus typhosus, B. dysenterice, and B. fcecalis alkaligenes are 

 not ordinarily pathogenic for the lower animals. They are, how- 

 ever, pathogenic for man, and since many of our diagnostic methods 

 for other diseases have been discovered through their study, they 

 are discussed briefly. 



Bacillus typhosus 



Synonyms. Bacillus typhi; B. typhi abdominalis; Eberth or 

 Eberth-Gaffky bacillus. 



Disease Produced. Typhoid fever in man. 



Eberth, in 1880, discovered the B. typhosus in the spleen and 

 other internal organs of the body of persons who had died of 

 typhoid fever. Gaffky, in 1884, cultivated the organism. It 



