Observations on the Use of Kendall's Medium in the Cultivation of Endamoeba histolytica

Abstract

The description by Kendall 1 , 2 of media containing unaltered protein and no peptones, meat extractives, or protein degradation products, thus approximating the living tissues of the body, led to an attempt to cultivate upon these media the pathogenic Endamoeba histolytica. This amoeba, well known to be a tissue parasite, can be cultivated in several media, and even in a simple mixture of normal salt solution and human blood serum. However, the parasite does not grow indefinitely in the more simple media that have been developed and it was thought that in the Kendall media the organism might find conditions more like those in the living tissues and that these media would prove suitable for cultivation.

A strain of Endamoeba histolytica originally isolated from a human case of amebiasis and which has been perpetuated in dogs was used in the experiments. Both the “plain” Kendall and the “clear” Kendall media were used, the media being planted with material obtained from the intestine of the dog containing numerous motile amebae. At the same time control cultures were made upon the Boeck-Drbohlav medium which is routinely used in the cultivation of Endamoeba histolytica.

The cultures were examined every day and transplants were made every 48 hours. It was noted that even after the first 48 hours the amebae were reduced in number and that after one or, at most, 2 transplants, they entirely disappeared. The cultures in the control tubes upon the Boeck-Drbohlav medium showed marked increase in the number of the amebae at the time of the first transplant and these cultures were transplanted 8 times at 48 hour intervals, at the end of which time the organisms were still present in the usual number found in cultures upon this medium.