Čepička I., Kutišová K., Flegr J. 2002: Molecular polymorphism of Tetratrichomonas gallinarum. Abstrakt, J.Eukaryotic Microbiology, 49, 7A.
ISSN 1066-5234,
IF 1,739
ABSTRACT. Tetratrichomonas gallinarum is a widespread parasite of birds, mainly
Galliformes and Anseriformes. This species usually infects caecum, but it was
found also in beak, salpinx and different visceral organs. Several strains were
also isolated from human mouth and lungs. There were originally described several
Tetratrichomonas species from different avian hosts, but on the basis of morphological
and infection studies only one species is presently considered to be valid.
We performed the phylogenetic analysis with 19 T. gallinarum strains, including
two human strains and 17 strains isolated from 8 different avian species. The
sequences of 5.8S rRNA with the flanking areas ITS1 and ITS2 (ITS) of these
19 strains were determined and used for construction of the phylogenetic tree
by the Neighbor-joining and Maximum parsimony method. The strains formed 5 clusters
A-E; sequences in each cluster were identical. Human isolates were placed in
clusters A and B. The sequence homology among clusters A, B and C (92.9% - 95.4%)
was higher than the sequence homology among four valid Trichomonas species (86%
- 89% ). However, the sequence homology of clusters D or E to clusters A, B
and C, as well as the sequence homology between clusters D and E was unexpectedly
low (78.2% - 91% ). We also sequenced and analyzed the gene for 16S rRNA from
one strain of each cluster. Again, the sequence homology between clusters D
and E, as well as between cluster D or E and clusters A, B and C, was lower
than the sequence homology between two Trichomonas species. Therefore we suggest
that our strains of Tetratrichomonas gallinarum could represent at least three
cryptic species.