Abstract
Species of Tetratrichomonas gallinarum and Trichomonas gallinae, are found in the digestive tract of birds. To investigate trichomonads of a lower intestinal tract of native chickens, we examined 72 feces samples from the different life stages of fowl species in Khorramabad County, Lorestan Province, Western Iran. Using microscopical examination, out of 72 collected samples, 26 (31.6%) bird feces samples were found infected with a trichomonad similar to T. gallinarum. A 527-bp fragment of 18S rRNA gene of T. gallinarum was amplified by PCR. The 18S constructed phylogeny indicates two different clades within T. gallinarum, suggesting that commensal T. gallinarum-like of the bird hosts may be the reason for the genetic divergence in T. gallinarum species complex.