Novel avian oropharyngeal trichomonads isolated from European turtle doves ( Streptopelia turtur ) and racing pigeons ( Columba livia ): genetic and morphometric characterisation of clonal cultures

Abstract

Extensive diversity has been described within the avian oropharyngeal trichomonad complex in recent years. In this study we developed clonal cultures from four isolates selected by their different ITS1/5.8S/ITS2 (ITS) genotype and their association with gross lesions of avian trichomonosis. Isolates were obtained from an adult racing pigeon and a nestling of Eurasian eagle owl with macroscopic lesions, and from a juvenile wood pigeon and an European turtle dove without clinical signs. Multi-locus sequence typing analysis of the ITS, small subunit of ribosomal rRNA (SSUrRNA) and Fe-hydrogenase (Fe-hyd) genes together with a morphological study by optical and scanning electron microscopy was performed. No significant differences in the structures were observed with scanning electron microscopy. However, the genetic characterisation revealed novel sequence types for the SSUrRNA region and Fe-hyd gene. Two clones were identified as Trichomonas gallinae in the MLST analysis, but the clones from the racing pigeon and European turtle dove showed higher similarity with Trichomonas tenax and Trichomonas canistomae than with T. gallinae at their ITS region, respectively. SSUrRNA sequences grouped all the clones in a clade that includes T. gallinae, T. tenax and T. canistomae. Further diversity was detected within the Fe-hyd locus, with a clear separation from T. gallinae of the clones obtained from the racing pigeon and the European turtle dove. In addition, morphometric comparison by optical microscopy with clonal cultures of T. gallinae revealed significant statistical differences on axostyle projection length in the clone from the European turtle dove. Morphometric and genetic data indicate that possible new species within the Trichomonas genus were detected. Taking in consideration the diversity in Trichomonas species present in the oral cavity of birds, a proper genetic analysis is highly recommended when outbreaks occur.

A New Feature of Nesting Ecology in the Vulnerable European Turtle Dove: Nest Site and Nesting Tree Sharing with Coexisting Species at Three North African Wetlands

“…From 1960 to 2020, the majority of studies concerning turtle doves investigated this game separately from other species that could exist in the same habitats, and this will miss a piece of precious information that would help in the conservation of this declining migrant bird [26]. In the best case, turtle doves were studied comparatively with conspecific competitors (Columbidae), such as laughing dove, collared dove, stock dove, and wood pigeon, mainly in geographical distribution [27][28][29][30][31][32], in feeding competition [29,33], in breeding biology [26,[34][35][36], and in parasite infestation [37,38]. On the contrary, this study has situated turtle doves among interspecific breeding species in wild nesting sites.…”

Trichomonas tenax: A Neglected Protozoan Infection in the Oral Cavities of Humans and Dogs—A Scoping Review

“…Other studies have reported on the occurrence of T. tenax in the oral cavities of dogs and cats [ 3 , 29 ]. Recently, T. tenax was detected in the cloaca of birds [ 30 , 31 , 32 , 33 , 34 , 35 ]. With T. tenax being found in so many different hosts, it is important to determine whether T. tenax is a human parasite, which is the predominant current view, or if it is a parasite of animal origin with zoonotic potential.…”

To get sick or not to get sick—Trichomonas infections in two Accipiter species from Germany

“…Recently, Girard et al ( 2014b ) identified the new species T. stableri as the parasite involved in mortalities of band-tailed pigeons ( Patagioenas fasciata monilis , Vigors 1839). The existence of isolates with a high similarity to the human pathogens Trichomonas vaginalis (Donné 1836) and Trichomonas tenax (Muller 1773; Dobell 1939) and the canid pathogen Trichomonas canistomae were reported from Europe, Brazil and the USA (Gerhold et al 2008 ; Grabensteiner et al 2010 ; Ecco et al 2012 ; Martínez-Herrero et al 2014 , 2017 ; Quillfeldt et al 2018 ). The occurrence of hybrid lineages was also recently reported (Alrefaei et al 2019 ).…”