124 



The Philippine Journal of Science 



1918 



terium should always react in a constant manner under constant 

 conditions of time and temperature. In testing the truth of 

 this statement, we have been led to the belief that, so far as the 

 dysentery bacilli are concerned, the proposition is almost if not 

 quite true, and that, so far as the practical determination of 

 strains is concerned, it may be accepted as a fact. 



Lehmann and Neumann (2) divide the dysentery bacilli into 

 four strains according to their action upon mannite, maltose, 

 and saccharose. The strains thus differentiated are: (1) 

 Shiga-Kruse, (2) Flexner, (3) Strong, and (4) Bacillus Y 

 (Hiss-Russell). The table of differentiations is as follows: 



Carbohydrate. 



Shiga- 

 Kruse. 



Flexner. 



Strong. 



Bacillus Y. 



Mannite _ . 



Blue 



Blue 



Blue 



Red 



Red 



Blue 



Red- _ 



Blue 



Red 



Red. 

 Blue. 

 Blue. 



Maltose . 



Saccharose 





Other writers, basing their opinions upon the carbohydrate 

 reactions, would differentiate them still further. It is a matter 

 of doubt whether the group would stand further differentiation 

 than that just indicated, provided we use pure carbohydrates 

 and properly control our results; and most bacteriologists are 

 content to recognize two strains of dysentery organisms ; namely, 

 those which ferment mannite and those which do not. It is 

 generally admitted that these two types, aside from their fer- 

 mentative differences, also show differences in their capacities 

 to produce toxin and to cross-agglutinate and cross-bacteriolyse. 

 It is doubtful whether there is any practical advantage to be 

 derived from going further than the recognition of these two 

 types. But it is certainly a fact that, among those which produce 

 acid in mannite solutions, there are strains which will and others 

 which will not ferment maltose, and there are also strains which 

 will and others which will not ferment saccharose. These last- 

 named saccharose fermenters seem to be very rarely isolated 

 from dysenteric stools, and their fermentation of saccharose 

 seems much slower and less decisive than does the action of these 

 bacteria as a group toward other carbohydrates upon which they 

 will act. In order to get comparable results with these reactions, 

 it is evident that the methods employed must be comparable. 

 It is also found that the results vary within certain limits when 

 dealing with the same set of organisms, depending upon whether 

 solid media or liquid media are used and also upon whether or 



