Prevalence of Tri­cho­monas gallinae with molecular characterisation and phylogenetic analysis in domestic pigeons using ITS1-5.8s rRNA-ITS2 gene in Alborz province, Iran

Avian trichomonosis is an important parasitic disease throughout the world caused by the protozoan Trichomonas gallinae, commonly seen in pigeons and wild birds. Lesions in the upper gastrointestinal tract (beak and crop) are complications of this disease. Currently, the diagnosis of this organism is made using laboratory methods including direct smear, culture medium and molecular methods. The aim of the present study was to survey the prevalence of T. gallinae in pigeons of Alborz province, Iran through molecular and phylogenetic identification using ITS1-5.8s rRNA-ITS2 gene. A total of 87 samples were collected from domestic pigeons from May to September 2019. The samples were taken directly from the mouth and larynx using an oral swab. Out of 87 collected samples, 28 (32.18 %) were positive using direct smear, culture and polymerase chain reaction (PCR) methods. Based on the results, the size of the amplification product of this gene was 372 base pairs. The results of this study were analysed using a phylogenetic tree and Neighbour-Joining (NJ) method. The present study showed high prevalence of T. gallinae in pigeons. Two types of T. gallinae genotypes, A and B, were found in pigeons. Also, the phylogenetic analysis of ITS1-5.8s rRNA-ITS2 sequences from positive samples, showed high coverage with sequences present in the GenBank.