Molecular characterization of Anaplasmataceae in Turkmen horses (Akhal-Teke breed) and ticks in racetracks, Iran.

Abstract

Due to the abundance of ticks on open grassy surfaces, racetracks may represent ideal scenarios for tick-borne pathogens. Therefore, in 2024/2025 Turkmen horses (Akhal-Teke breed) and ticks collected by dragging in paddocks of Iran were screened for Anaplasmataceae using Sanger sequencing of 16S rRNA, TRP36 and dsb genes. Amongst 200 horses, 11 (5.5 %) tested positive without signs/symptoms, being 8 (4 %) for Ehrlichia canis and 3 (1.5 %) for Anaplasma ovis; no difference in prevalence was found by gender and age (p > 0.05). All ticks were identified as Hyalomma asiaticum and Haemaphysalis sulcata. On 20 tick pools, 7 (35.0 %) were positive (n = 4, 20 % - E. canis and n = 3, 15 % - A. ovis). A close phylogenetic relationship was found between the pathogens herein and GenBank. The prevalence of Anaplasmataceae in asymptomatic horses indicates these animals as reservoir of infection, and the zoonotic potential of E. canis suggests a risk to racetrack visitors and workers.