156 BACTERIOLOGY FOR NURSES 



AMCEBIC DYSENTERY 



Dysentery is a term used to designate an inflamma- 

 tion of the colon, accompanied by excessive diarrhoea; 

 but dysentery occurs in several distinct forms which 

 are due to different organisms. Thus, several forms 

 of dysentery are due to bacteria Bacillus dysen- 

 terice of which there are two or three varieties, 

 in other words are due to vegetable organisms (bac- 

 teria) ; while amoebic dysentery, a chronic form usually 

 occurring in the tropics, is caused by a protozoon 

 known as entamceba histolytica. In amoebic dysentery 

 large numbers of amoebae are found in the intestinal 

 walls, which they penetrate, causing characteristic 

 ulcerations. The colon and rectum are most affected, 

 although the internal organs, notably the liver, are 

 frequently invaded, resulting in large abscesses of the 

 liver. 



The amoebae of dysentery average about 30ft in 

 diameter, are actively motile, and multiply by spore- 

 formation. They possess protrusions for locomotion 

 - pseudopodia which they use to penetrate the 

 mucous membranes. 



Artificial cultivation of the amoeba of dysentery 

 has been attended with great difficulties, and has 

 been successful only by the use of elaborate special 

 methods. 



