QO STUDY AND IDENTIFICATION OF BACTERIA. 



produced which, being absorbed, are eliminated by the large intestine 

 with resulting necrosis. Flexner, by injecting rabbits intravenously 

 with a toxic autolysate, produced characteristic intestinal lesions. 

 There are two main types of dysentery bacilli : 



1. Those producing acid in mannite media the acid strains 

 (Flexner-Strong types). 



2. Those not developing acid in mannite (Shiga-Kruse types). 

 Ohno finds that fermentative reactions do not correspond to immunity 

 ones. Thus an acid strain used to immunize a horse may produce a 

 serum more specific for a nonacid strain. The Shiga type is very 

 toxic in cultures, while the Flexner type does not seem to possess a 

 soluble toxin. At the Lister Institute injections of a soluble toxin 

 produced a serum of marked antitoxic power. Such a dysentery 

 serum, which is probably both antitoxic and antimicrobic, is of curative 

 value. Shiga immunized horses with polyvalent cultures and obtained 

 a polyvalent serum which has reduced the death-rate about one-third. 



The dysentery bacillus is present in the mucous stools during the 

 first five or six days of the disease. By the tenth day it has probably 

 disappeared. In all cultural respects the dysentery bacillus resembles 

 the typhoid, and the only practical method of distinguishing these two 

 organisms, other than by agglutination reactions, is by the nonmotility 

 or exceedingly slight motility of the dysentery bacillus. The dysentery 

 bacilli do not form those threads or whip-like filaments so characteristic 

 of typhoid cultures. The dysentery bacillus is not found in the blood 

 and hence is not eliminated in the urine. It is found in mesenteric 

 glands. In dysentery patients agglutination phenomena do not show 

 themselves until about the twelfth day from the onset. Hence, this 

 procedure is of no particular value in diagnosis. It is of value, how- 

 ever, to identify an organism isolated from the stools at the commence- 

 ment of the attack, using serum from an immunized animal or a 

 human convalescent for the agglutination test. 



Park and Collins, in 1904, separated various strains of dysentery 

 bacilli into three groups: 



i. Original Shiga strain. No indol. No fermentation of 

 mannite, maltose or saccharose. 



