Pentatrichomonas ardin delteili is a parasitic flagellate of man having consistently in its vegetative phase five anterior flagella which are differentiated into two groups, a clustered group of four beating together at a slower rate, and a single independent anterior flagellum beating synchronously with the undulating membrane at a more rapid rate.
A knowledge of this independent behavior of the two groups of flagella is of assistance in determining the number of flagella since the independent one lies adjacent to the other four only once in each of its beats and must as a rule be seen at a distance from the other four.
Pentatrichomonas eats red blood corpuscles and is accompanied by clinical indications of pathogenicity in the form of chronic, persistent, continued diarrheas with fetid stools. It resists emetin preparations and arsenicals.
Pentatrichomonas survives in liquid stools for twenty-four days, in rain, creek, and tap water for three days, and in normal salt solution for thirteen days. No cysts have been observed. It is probably spread to new hosts by drinking water or food contaminated with the motile stage.
Pentatrichomonas can be cultured in 10 per cent rabbit, guineapig, and human serums in Locke's solution at room and body temperatures.