Molecular evidence of Theileria equi infection in Hyalomma anatolicum ticks infested on sero-positive Indian horses

Abstract

A sizeable Indian equine population is considered to be pre-immune carrier of Theileria equi infection. In this study we confirmed the presence of T. equi specific DNA in Hyalomma anatolicum ticks which were infested on sero-positive horses. Fifty two Indigenous horses were randomly selected from endemic areas and their blood and tick samples were collected. Tick salivary glands and blood samples were processed for separation of DNA and serum, respectively. Serum samples were analyzed by EMA-2ELISA and nine horses were found positive for T. equi specific antibodies. Species-specific primers were designed from EMA-2 gene of T. equi, so as to amplify 398 bp fragment in PCR. The gene fragment was amplified in PCR on the DNA samples (from blood) from these nine sero-positive horses. Corresponding six tick's DNA samples collected from these nine seropositive animals were observed positive in PCR. Further, qPCR assay demonstrated presence of T. equi DNA in infected tick's salivary glands, which was also confirmed by microscopic examination of infected acinar. This study concluded that Hyalomma anatolicum ticks infested on T. equi seropositive horses have sporozoite developmental stage in their salivary glands, which is an evidence for transmitting potential of these tick among Indian horse population.

Seroprevalence and Risk Factor Associated with Endemicity of Theileria equi Infection in Horses in Rajasthan State, India

“…Serum samples were screened by ELISA, developed at the equine piroplasmosis laboratory of National Research Centre on Equines (NRCE) for detection of antibodies against T. equi (Kumar et al, 2013;Bhagwan et al, 2015). Briefly, ELISA plate coated with recombinant protein (rEMA) and incubated overnight at 4  C. Next day the plate was blocked with 3% BSA-PBS for 1 h followed by washing with PBS containing 0.05% Tween-20 (PBS-T) four times.…”

“…(Kouam et al, 2010;Moretti et al, 2010;Abutarbush et al, 2012;Steinman et al, 2012;Peckle et al, 2013). Nevertheless, infected ticks' infestation is responsible for making the equids T. equi seropositive (Bhagwan et al, 2015). Kaccha housing conditions are responsible for the propagation of ticks breeding.…”

Comparing the efficacy of three diagnostic tools (microscopic examination, conventional PCR, and Real-Time PCR) in detecting Theileria equi infection among Egyptian equines

“…This parasite has endemicity in tropical, subtropical and some temperate zones of the globe (Ozubek & Aktas, 2018;Souza et al, 2019). Several tick vectors can transmit T. equi, the most vectors are those belonging to genera Dermacentor, Boophilus, Rhipicephalus, and Hyalomma whose distribution have a direct relation to the prevalence of T. equi (Bhagwan et al, 2015). Economically, T. equi has a signi cant effect on equine causing severe economic losses with impairment of equine movement.…”