Prevalence, molecular characterization, and physiological impacts of Theileria annulata in bovines across three Egyptian governorates.

Theileria annulata infection poses a significant threat to livestock health and production worldwide. This study investigated the prevalence, morphological characteristics, molecular identification, and physiological impacts of T. annulata in cattle and buffaloes across three Egyptian governorates: Beni Suef, Faiyum, and Giza. Blood samples from 300 cattle and 250 buffaloes were analyzed using microscopic examination, molecular techniques, and biochemical assays. Giemsa-stained blood smears revealed intraerythrocytic piroplasms and intralymphocytic schizonts. These morphological findings were subsequently confirmed by PCR targeting the 18S rRNA gene, which definitively identified T. annulata. Phylogenetic analysis of the 18S rRNA sequences revealed genetic diversity among isolates and their relationships with global strains. The overall prevalence of T. annulata was 25.3 %, with 23.7 % in cattle and 27.2 % in buffaloes. Prevalence varied across governorates: Beni Suef (24.0 % cattle, 27.7 % buffaloes), Faiyum (23.0 % cattle, 27.7 % buffaloes), and Giza (24.0 % cattle, 26.2 % buffaloes). In cattle, infection rates were similar between males and females, while in buffaloes, males showed higher rates than females. Age-wise analysis in cattle revealed an increasing trend with age, while buffaloes exhibited a U-shaped pattern. Seasonal dynamics showed highest infection rates in summer for both species, followed by spring, autumn, and lowest in winter. Oxidative stress markers (SOD, CAT, and MDA) and pro-inflammatory cytokines (IL-1β, TNF-α, IL-6) were significantly elevated in infected animals. This multi-faceted approach provides valuable insights into the epidemiology, genetic diversity, and host-parasite interactions of theileriosis in Egypt, highlighting the need for targeted control strategies and further investigation into pathogenesis mechanisms.