Phylogenetic diversity and DNA barcoding of the camel tick Hyalomma dromedarii (Acari: Ixodidae) of the Eastern region of Saudi Arabia

Hard ticks are causative agents of physical illness and vectors of important diseases of human and livestock. The hard tick Hyalomma dromedarii Koch, 1844 is a major ectoparasite of livestock in the Kingdom of Saudi Arabia (KSA), of which, the one-humped dromedaries Camelus dromedarius is the most economically and culturally important and a potential reservoir of Middle East respiratory syndrome coronavirus (MERS-CoV) disease. Here we report on the molecular phylogenetic diversity of H. dromedarii collected from camels in the Eastern Province of KSA based on the mitochondrial cytochrome oxidase I (COI) gene. Maximum likelihood (ML) phylogenetic analysis of COI sequences of the studied ticks identified 11 haplotypes. All H. dromedarii ticks from KSA belonged to eight haplotypes diverged into two distinguished genetic clades (A-B). These results indicate that H. dromedarii ticks from KSA are monophyletic species with two distinguished lineages with low intra-specific genetic divergence and sharply structured isolated populations with high level of genetic differentiation. This is a first report of DNA barcode of H. dromedarii ticks from KSA and the Arabian Peninsula, which is an important step towards broader phylogenetic studies on larger tick samples from the region. The studies are important for better understanding its interactions with camels and other hosts and role in zoonotic disease transmission (e.g. MERS-CoV or Alkhurma virus) to pinpoint effective control strategies.