Rana Elseadawy

Sheep and goats are significant livestock in Egypt economy; however, there is still a lack of published data investigating piroplasm infections, particularly in goats. Blood samples were collected from 182 apparently healthy goats from herds in Aswan (n = 100) and Assiut (n = 82) governorates in Upper Egypt. Microscopic examination of thin blood smears stained with Giemsa revealed 33 positives for piroplasm infection (18.13%). The logistic regression analysis revealed that the location, Assiut compared to Aswan governorate (P ≤ 0.001), was the significant risk factor for infection. Additionally, tick infestations were also identified as a risk factor for infection (p < 0.05) according to the multivariate logistic regression model. Twenty microscopic positive samples were shown to be positive for T. ovis using 18S rRNA-PCR assay, but none of them tested positive for B. ovis and T. lestoquardi. Nucleotide sequencing of five isolates out of the twenty confirmed T. ovis infection. Currently, there is no available information on the level of genetic diversity among T. ovis populations, and all isolates have been sequenced using the 18S rRNA gene. A total of 445 GenBank published T. ovis 18S rRNA nucleotide sequences were collected including this study isolate and subjected to various genetic analyses. The isolates were clustered into 37 haplotypes with low haplotype and nucleotide diversity, and high sequence conservation. A major haplotype was identified, and dominated across all sampled hosts and countries. Additionally, comparisons of T. ovis populations across different hosts and geographical regions showed limited genetic differentiation and strong gene flow. This data suggests that the analysed region of the 18S rRNA gene is highly conserved. Identification and sequence analysis of polymorphic markers could be useful for understanding the infection dynamics and evolutionary relationships among Theileria spp. infecting small ruminants.