Molecular investigation of hindgut flagellates from turkeys and pheasants in Hungary confirms the endemicity of a new species closely related to Histomonas meleagridis

To compensate the lack of molecular-phylogenetic data on hindgut flagellates in Hungary, galliform birds were monitored in five regions for two years. Samples were collected from 11 turkeys (from 4 flocks) and 9 pheasants (from 3 farm-raised flocks) suspected to have histomonosis. These samples were molecularly and phylogenetically analysed. In nine turkeys, five 18S rRNA genes and two ITS sequence variants of Histomonas meleagridis were identified. These variants were identical between the caecum and liver of the same bird in most cases, but different 18S variants were identified between sampling sites. In one turkey, an unnamed species, here designated as “Dientamoebidae sp. HUN35”, was identified. Its 18S rRNA gene sequence was near-identical (99.6–99.3%) to the sequence reported previously; and the ITS-1/5.8S/ITS-2 region confirmed a close relationship with H. meleagridis and Dientamoeba fragilis . In one pheasant, Tetratrichomonas gallinarum was detected. Different 18S rRNA variants had either identical or different ITS sequences, thus optimally, both should be used for molecular epidemiological studies. Our results suggest the unnamed Dientamoebidae sp. has been present in Hungary since its first detection in 2010 and the host range of this species as well as that of T. gallinarum is broader than previously thought.