Because of the common pathology, protein expression and drug resistance mechanisms- though in different hosts- of the luminal trichomonads Trichomonas vaginalis, T. gallinae and T. muris, doubts were raised concerning their phylogenetic
relationship. The random amplified polymorohic (RAPD) technique for genetic DNA polymorphism studying was used to genetically characterize and assess their interspecies polymorphism. Results showed a high statistical support for the close
relationship between the tested parasites and proved a tight association between Tritrichomonas muris and T. gallinae as well as a high genetic similarity between T. muris and T. vaginalis.