Helminthological Survey of the European Brown Hare (Lepus europaeus) in Türkiye, with A Note on Haplotype and Network Analyses of Dicrocoelium dendriticum and Passalurus ambiguus

Several studies have been conducted to determine the prevalence and presence of helminth species in European brown hare populations in various parts of its geographical range. However, there are limited data on helminth species circulating among European brown hare populations in Türkiye. The aim of this study is to investigate the presence and prevalence of helminth species in European brown hares in Türkiye, to perform phylogenetic analyses of the identified species, and to determine haplotype diversity and network properties of Dicrocoelium dendriticum and Passalurus ambiguus. Internal organs from 109 European brown hares were collected and examined for the presence of helminth species. The helminths detected were identified based on their morphological properties. DNA extraction was performed from a randomly selected sample of each species, and the COI gene region was amplified by PCR. Bidirectional DNA sequence analysis was done, and the obtained nucleotide sequences were uploaded to GenBank. Phylogenetic analyses of helminth species were performed, and their genetic characteristics were revealed. Additionally, haplotype diversity and network properties of D. dendriticum and P. ambiguus were determined. It has been determined that 70.64% (77/109) of animals were infected with at least one helminth species. While 35.78% (39/109) of the animals were infected with one helminth species, 34.84% (38/109) were infected with two or more helminth species. Six helminth species, Dicrocoelium dendriticum, Andrya rhopalocephala, Mosgovoyia pectinata, Trichuris leporis, Passalurus ambiguus, and Nematodirus leporis, were identified. Andrya rhopalocephala was detected for the first time in Türkiye. Phylogenetic analyses of the COI gene of these helminth species, except for T. leporis, were performed, and all obtained nucleotide sequences were deposited to GenBank. Furthermore, haplotype and network analyses of D. dendriticum and P. ambiguus isolates were done, and it was determined that 11 D. dendriticum haplotypes and five P. ambiguus haplotypes were found to be circulating among hosts in different parts of the world. This study is the first to perform microscopic and molecular detection of helminth species in European brown hares in Türkiye. The study determined that helminth prevalence is quite high in this animal in the country. It is considered that the data obtained within the aim of the study will contribute to understanding the epidemiology and genetic characteristics of helminth species circulating in wild animals.