648 AMCEBIC DYSENTERY 



Dysenteric material was obtained from China, and portions of 

 it which were found to contain the cysts were thoroughly dried. 

 Some of this material was given with food to cats by the mouth, 

 and typical dysentery resulted, the amoebae being found in the 

 stools. No results follow when the material ingested merely 

 contains the vegetative form of the organism, as it is readily 

 destroyed in the contents of the stomach. As stated above, 

 dysenteric lesions have been produced in the cat by inoculation 

 with E. tetragena. 



Musgrave and Clegg produced amoebic colitis in monkeys 

 by means of cysts from cultures, and such results were obtained 

 whatever was the source of the amoebae that is, with those 

 obtained from water, vegetables, etc., as well as with those 

 from dysenteric material. They also produced liver abscess 

 by direct injection into the liver, and in some instances only 

 amoebae were present in the abscesses. 



Investigations with regard to E. coli seem to show that it 

 is a harmless organism and that it is frequently present in the 

 intestines of healthy individuals. Schaudinn found that in East 

 Prussia as many as 50 per cent, of the population were in- 

 fected with it. The administration of the amoebae, or of the 

 cysts by the methods mentioned above, produced no result in 

 animals. It has, however, been shown that when the eight- 

 celled cysts are swallowed by persons who are free from the 

 parasite the E. coli appears in the large, intestine in a com- 

 paratively short period of time. It accordingly appears that in 

 the case of both organisms it is the cysts alone which give rise 

 to infection. Confirmatory results with regard to the common 

 occurrence of E. coli were obtained by Craig in San Francisco. 



From the above facts, all of which have received ample 

 confirmation, there can be no doubt that the amoebae described 

 are the cause of the form of dysentery with which they are 

 associated. The position of E. histolytica and E. tetragena as 

 pathogenic species appears to be established, but there is mani- 

 festly a fairly large proportion of cases of amoebic dysentery 

 where the organisms are of other species not yet differentiated. 

 Much further investigation is still required on this point and 

 also with regard to the saprophytic existence of pathogenic 

 amoebae. We may add that the serum of patients suffering from 

 amoebic dysentery gives no agglutinating reaction with Shiga's 

 bacillus of dysentery (vide p. 397). 



It is important to note that cases of amoebic dysentery have 

 been recorded both in France and England in patients who have 

 never resided outside these countries. 



