CHAPTER XXVI ] 

 DYSENTERY BACILLI 



Dysentery is a disease produced by ameba and by a number of closely 

 related bacilli. The _bacillary form of the disease occurs sporadically and 

 in epidemics in many parts of the temperate and torrid zones. 



The distribution of the various types of dysentery bacilli is not fully 

 known, and it may be the same for each. 



Morphology. The dysentery bacilli have the same size and shape as the 

 typhoid bacillus; most of them are not motile. 



In staining, growth in bouillon, agar, gelatin, blood serum and potato 

 they are indistinguishable from the typhoid bacillus; they differ from is 

 and from each other in affect on carbohydrates and agglutination reaction. 



HISS AND ZINSSER'S CLASSIFICATION * 



Bacillus 



Dysentery (Shiga-Kruse Type) 

 Dysentery (Hiss-Russel Type) 

 Dysentery (Flexner Type) 

 Dysentery ("Rosen") 



Dextrose, levulose, galactose 



Acid formed but no gas 

 Acid formed but no gas 

 Acid formed but no gas 

 Acid formed but no gas 



Litmus milk 



Primary acidity followed by alkalinity Non-motile 

 Primary acidity followed by alkalinity j Non-motile 

 Primary acidity followed by alkalinity Non-motile 



Acid 



Slightly motile 



Maltose fermented after some days 



With few exceptions dysentery bacilli do not form indol. They do not 

 form spores. 



Resistance. Outside the human body the resistance of the dysentery 

 bacilli to germicidal agents is much less than that of the typhoid bacillus. 



*"A Text Book of Bacteriology" Hiss and Zinsser. 



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