Phylogenetic study of Theileria ovis and Theileria lestoquardi in sheep from Egypt: Molecular evidence and genetic characterization

Background and Aim: Ovine theileriosis caused by Theileria ovis and Theileria lestoquardi is an important infectious disease affecting small ruminants in regions of the tropic and subtropic zones. There is limited studies about ovine theileriosis in Egypt; so the present study aims to assess the occurrence of ovine theileriosis in Egypt at the molecular level. Materials and Methods: Blood samples were collected from 115 randomly selected sheep, which were apparently healthy; the ages of the sampled sheep ranged from 1 to 5 years old, from a local breed (barkae and balade), and showed no symptoms indicating infection with Theileria spp. The study was conducted in three governorates representing Lower Egypt (Menoufia and Beheira) and Upper Egypt (El-Wady El-Geded). All blood samples were subjected to polymerase chain reaction (PCR) and semi-nested PCR to target Theileria spp. 18S rRNA genes. Positive samples were sequenced, and these sequences were analyzed using nucleotide basic local alignment search tool (BLAST). Results: Six animals (5.22%) were PCR-positive carriers for ovine theileriosis. Nucleotide BLAST and phylogenetic analyses of the six obtained sequences showed that T. ovis was present in five animals (4.37%) in Menoufia (n=2) and El-Wady El-Geded (n=3), whereas T. lestoquardi was detected in 1 animal (0.87%) in El-Wady El-Geded. Conclusion: This study is the first to provide molecular evidence, genetic characterization, and phylogenetic analysis of ovine Theileria spp. in Egypt. Specifically, T. lestoquardi and T. ovis carrier statuses of sheep were confirmed. These results highlight the importance of developing an effective control strategy against ovine theileriosis carriers that might develop and/or spread theileriosis.