THE TYPHOID-COLON GROUP 



119 



1. The Eberth or typhoid group. There are three important patho- 

 gens in this group: the B. typhosus, the B. dysenteric, and the B. facalis 

 alkaligenes. The color of litmus milk is practically unaltered and there 

 is no gas production in either glucose or lactose bouillon. No coagu- 

 lation of milk. No reduction of neutral red. The B. typhosus and 

 the B. facalis alkaligenes are actively motile, while the B. dysenteries 

 is nonmotile or practically so. 



During the first twenty-four to forty-eight hours there is a moderate acid produc- 

 tion by typhoid, so that the milk culture is less blue, while with the B. facalis alka_ 

 ligenes the alkalinity is intensified from the start, so that the blue color is deepened^ 



2. The Gartner or hog cholera group. Besides organisms important 

 for animals and probably at times for man, such as B. cholera suum 

 and B. psittacosis and B. icteroides (interesting historically as having 

 been reported as the cause of yellow fever by Sanarelli), we have two 

 pathogens: i. B. enteritidis (Gartner's bacillus) and 2. B. paratyphoid 

 B. In this connection it may be stated that the present view is that 

 hog cholera is caused by an ultra-microscopic organism and not by the 

 B. cholera suum. 



These organisms cannot be separated culturally, but only by immunity reactions. 

 They do not turn litmus milk pink. They produce gas in glucose bouillon, but not 

 in lactose. They very powerfully reduce neutral red with the production of a yellow- 

 ish fluorescence. They do not coagulate milk. There is a transient acidity in the 

 litmus milk, but becoming shortly afterward alkaline, the lilac-blue color is intensified. 

 Both organisms are motile. 



3. The Escherich or colon group. These turn litmus milk pink, 

 coagulate milk, reduce neutral red, and show varying degrees of motil- 

 ity. The three groups of organisms just described are nonliquefiers of 

 gelatin. Two intestinal organisms, the B. cloaca and the Proteus vul- 

 garis, differ in liquefying gelatin. 



Bacillus Typhosus (Eberth, 1880; Gaffky, 1884). This organism 

 may be isolated from the stools, urine, and the blood of typhoid patients. 



At postmortem it can be best isolated from the spleen, but is also present in 

 Peyer's patches which have not ulcerated. When ulceration has occurred contami- 

 nation with B. coli, is almost sure. Cultures may be obtained from the liver also. 

 In sections made from spleen the Gram-negative bacilli are apt to be decolorized. 

 Thionin, then blotting and clearing in oil or xylol, shows the clumps of bacilli lying 

 between the cells. 



Formerly it was supposed that by the differences in the thickness of the film of 

 a colony or by its varying shades of grayish-blue, we possessed data of importance in 

 differentiating typhoid from related organisms. 



