Morphological and Molecular Identification of Ixodid Ticks that Infest Ruminants in Erbil province, Kurdistan Region-Iraq

Abstract

A cross- sectional survey was conducted in Erbil province from April to July 2021 to estimate the prevalence of major Ixodid ticks on ruminants and to identify tick species using morphological and molecular tools. A total of 687 animals (202 cattle, 287 sheep and 198 goats) examined, and 254 (36.9 %) were infested. About 381 ticks were collected from examined animals. The result identified two genera of six species of the hard ticks based on morphological, molecular investigation. The identified adult ticks morphologically were belonging to the two Ixodid genera, among which three species belonged to the genus Hyalomma (Hyalomma marginatum, Hyalomma anatolicum and H. exacavatum), and three species belonged to the genus Rhipocephalus (Rhipocephalus sanguineu, Rhipocephalus turanicus, and Rhipocephalus B. annulatus). R. annulatus was the dominant tick species infesting cattle with 50% which was significantly higher at P>0.05 than the other isolated species. Whereas H. excavatum and R. sanguineus was the prodominant tick species infesting sheep with 29.1% and 28.3 %respectively. While the infestation rate on goats was 16.7%, R. sanguineus was the most prevailed species infesting goats with 45.4% at (P>0.05). R. sanguineus were the predominant tick reported in Erbil governorate with 29.1% at (P>0.05)., while H. excavatum was reported in low percentage in Erbil at 10.2%. DNA samples from sixty ticks were chosen for molecular studies in order to detect tick species using a conventional PCR targeting the 16S rRNA gene. All sequences were subjected to a Basic Local Alignment Search Tool (BLAST) to determine their identities and assess their homologues and similarities to those in the Gen Bank. PCR and the sequencing have confirmed the morphological-based identification, Phylogenetic study revealed that the three Rhipicephalus genotypes revealed from the current study with accession number (MZ663757-MZ663759) were have a highly identical nucleotide sequence 99-100% with a strain of a Rhipicephalus turanicus, R. annulatus and R. sanguineus strain sequence (KY583068, MN594491 and MN594492) from China, and Iraq respectively. On the other hand phylogenetic analysis of Hyalomma genotypes from the present work with accession number (MZ663760-MZ663762) were closely related to a Hyalomma anatolicum, H. marginatum and Hyalomma exacavatum (MK829042, MG418663, and KP210047) from Egypt, Turkey and India respectively.