Molecular identification and phylogenetic relationships of trichomonad isolates of galliform birds inferred from nuclear small subunit rRNA gene sequences

Abstract

Histomonas meleagridis is the etiological agent of histomonosis or blackhead disease. Recently, genotyping, based on polymerase chain reaction and sequencing of internal transcribed spacer-1 sequences was applied to various isolates originating from fowl. Three genotypes were described: types I and II isolates were associated with clinical disease and probably derived from H. meleagridis, whereas, type III isolates were not disease-associated and likely corresponded to Parahistomonas wenrichi according to morphological observations. However, this latter species has never been characterized at the molecular level and its phylogenetic relationships with other parabasalids remained hypothetical. To confirm the identification of these isolates, small subunit rRNA gene sequences were obtained from representatives of types I, II, and III and analyzed in a broad phylogeny including 64 other parabasalid sequences. From our phylogenetic trees, we confirmed that types I and II isolates were closely related, if not identical, to H. meleagridis, while type III isolates represented P. wenrichi. Both species clustered together with high support. This grouping suggested that speciation leading to these two species inhabiting the same hosts and ecological niche occurred recently in birds. In addition, speciation was likely followed by loss of pathogenicity in P. wenrichi.

Multi-Locus Typing of Histomonas meleagridis Isolates Demonstrates the Existence of Two Different Genotypes

“…However, since the rest of the sequence was determined only once it is not clear whether such trend is present throughout the sequence. Later, Mantini et al [18] also detected micro-heterogeneity in the 18S rDNA of H. meleagridis when sequencing two clones of PCR products that amplified the 1.56 kb of 18S rDNA region. However, authors of both studies commented that amplification errors could not be excluded when explaining the nature of micro-heterogeneity in 18S rDNA.…”

The ambiguous life ofDientamoeba fragilis: the need to investigate current hypotheses on transmission

“…Parahistomonas wenrichi [synonym: Histomonas wenrichi (Mantini et al 2009)] is similar to Histomonas in terms of its life cycle and biology. Like Histomonas, Parahistomonas is spherical though is approximately 1·5 times larger than Histomonas (Levine, 1985).…”

“…According to phylogenetic studies, the closest relatives of Dientamoeba include Histomonas, Parahistomonas and members of the genus Tritrichomonas (Gerbod et al 2001(Gerbod et al , 2002Ohkuma et al 2005;Mantini et al 2009). A simple phylogenetic tree constructed for the purposes of this discussion summarizes these relationships ( Fig.…”

Isolation and Characterization of Novel Trichomonas gallinae Ribotypes Infecting Domestic and Wild Birds in Riyadh, Saudi Arabia

“…Trichomonosis is a serious disease that caused by the single celled flagellate protozoan parasite T. gallinae (Stabler, 1947b), and is a global infectious disease usually affecting Columbiformes as primary hosts (Bunbury, 2011, Stockdale et al, 2015, Abouhosseini Tabari and Youssefi, 2018, Swinnerton et al, 2005. However, it can jump from Columbiformes to many different bird species around the world, including Psittacines (McKeon et al, 1997), Galliformes (Mantini et al, 2009), Strigiformes (Rogers et al, 2016, Cousquer, 2005, raptors (Falconiformes) (Sansano-Maestre et al, 2009), and Passerines (Burton andDoblar, 2004, Lehikoinen et al, 2013) The poultry market in the capital of Saudi Arabia contains a wide variety of birds of many different species. Some of these birds, such as chickens, ducks, and pigeons, derive from local poultry farms; however, some, such as ornamental birds, parrots, and wild migrating birds such as falcons, are importated from outside the country.…”