In the present study the interaction of three genetically different clonal cultures of Trichomonas gallinae and Tetratrichomonas gallinarum with a permanent chicken liver (LMH)
and a permanent quail fibroblast (QT35) cell culture was studied. Proliferation of T. gallinae
cells was associated with a disintegration of the cell monolayer. The initial lesions on the
LMH monolayer consisted of a progressive accumulation of the flagellate, forming clumps
attached to the monolayer. A prolonged incubation time was characterized by appearance of holes in the cell monolayer with accumulation of trichomonads at their periphery. According
to the severeness of the monolayer disruption differences among three tested T. gallinae
clones were noticed. Furthermore, filtrates obtained either from axenic cultures of T. gallinae or from infected cell cultures produced a cytopathogenic effect similar to the protozoal
cells, on both types of cell cultures. However, the destructive effect of the flagellates and
their cell-free filtrates was much more pronounced on the LMH monolayer in comparison
with the QT35 cells. Furthermore, freshly seeded LMH and QT35 cells suspended in cell-free
filtrates of T. gallinae were unable to form a confluent monolayer. In comparison to T. gallinae,
clonal cultures of T. gallinarum or their cell-free filtrates produced no effect on both
types of monolayers. Interestingly, the cell-free filtrates obtained from both trichomonad
species had an effect on the viability of both cell cultures. However, the cytotoxic effect of T.
gallinarum filtrates was less severe than that recorded by T. gallinae. Consequently, for the
first time a destruction of specified monolayers induced by T. gallinae-free filtrates could
be demonstrated.