DYSENTERY 



125 



reaction. Subsequently the litmus is reduced and the clot digested giving a dirty 

 yellowish-brown fluid. Indol is rarely produced. The cultures generally have a 

 putrefactive odor. In infective jaundice (Weil's disease) this organism has been 

 reported as the cause. Organisms of this group were formerly designated as B. 

 termo. 



Bacillus Dysenterise (Shiga, 1898). Dysentery bacilli produce a 

 coagulation necrosis of the mucous membrane of the large intestine 

 and occasionally of the lower part of of the ileum. Polymorphonu- 

 clears are contained in the fibrin exudate. 



It was formerly thought that these lesions were of local origin, but the present 

 view is that toxins are 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. The toxin with- 

 stands a temperature of 7oC. without being destroyed. The toxin may cause 

 joint trouble. 



There are two main types of dysentery bacilli: 



1. Those producing acid in mannite media the acid strains (Flex- 

 ner-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. Hiss, however, found that 

 organisms similar in fermentation reactions agreed in agglutination 

 ones. The Shiga type is very toxic in cultures, while the Flexner type 

 does not seem to possess a soluble toxin. 



Clinically the toxaemia of cases of dysentery due to Shiga types is marked while 

 that from Flexner strains is slight. 



We often designate the Shiga strains as the toxic group and the acid-producing 

 strains as the nontoxic. The "Y" type of organisms also produces acid in mannite. 

 The following is the Lentz table: 



Lentz recognizes 4 types of dysentery bacilli for the differentiation of which he 

 uses mannite, maltose and saccharose bouillon with litmus as an indicator. 



A strain which ferments not only mannite, dextrose, maltose and saccharose, 

 but dextrin as well, is known as the Harris type. 



