The Action of Hydrochloric Acid upon Cultures ofTrichomonas

Abstract

The question of the mode of transmission of theTrichomonasof man from one host to another is of particular interest because no authentic encysted stage is known.Many workers have attempted to infect “clean” animals by the mouth with active trichomonads from a variety of hosts, either from cultures or directly from faeces. The results are conflicting. Thus Escomel (1913) fed faeces containingTrichomonas intestinalis(= T. hominis) from a human case of dysentery to a rabbit, a guinea-pig, a cat, and a dog, and obtained a positive result in the dog. He does not, however, state that he examined his animals, to find whether they had any similar natural infections, before performing his experiments. Boyd (1919) fed a culture ofTrichomonas intestinalis(= T. hominis), mixed with milk, to a white rat and infected it. He had previously examined this rat and one used as a control and found them to be free from this flagellate. He was, himself, uncertain whether the infection was due to the free flagellates or their “cysts“ which he says were present in the culture. The cysts figured by him (Plate XI, figs. 7–17) appear to be rounded-up and degenerating trichomonads. Pringault (1920) fedTrichomonas intestinalis(= T. hominis) to a cat, a guinea-pig, a rabbit, and a white rat, without establishing an infection in any one of them.