Exploring the frequent occurrence and characterization of Cytochrome B gene in Theileria annulata in cattle

Abstract

<title>Abstract</title> Bovine theileriosis caused by <italic>Theileria annulata</italic> (<italic>T. annulata</italic>) that result in high mortality and financial losses for the livestock industry in Egypt. For this study, fifty cattle were utilized. Whole blood samples were collected for laboratory analysis. Giemsa-stained blood smears were employed to detect <italic>Theileria</italic> infection. Polymerase chain reaction (PCR) was used to evaluate various target genes like 30-kDa and Cyto B of <italic>T. annulata</italic>. Nine (18%) samples tested positive for piroplasm of <italic>Theileria</italic> by microscopic examination of blood smear. Twenty one (42%) of the analyzed samples tested molecularly positive depended on 30-kDa gene, while 10 (20%) samples were positive based on Cyto B gene. In our study, we carried out DNA sequencing and phylogenetic analysis of <italic>T. annulata</italic> using the Cyto B gene. The PCR products' phylogenetic analysis of the Egyptian strain of <italic>T. annulata</italic> (Assiut) showed nucleotide identity ranging from 96.16–98.92% with <italic>T. annulata</italic> strains of various governorates (Sharkia and Qulyubia) of Egypt, Sudan, Tunisia, Turkey, and India. The isolates obtained were found to be closely clustered with an isolate from Sudan (accession number LC431533). We identified thirty point mutations at the amino acids sequences. There was substantial variance (P &lt; 0.05 and P &lt; 0.01) between age and sex of tested cattle, respectively and percentages of <italic>T. annulata</italic> infection. The data obtained from our study in characterization of Cyto B gene of <italic>T. annulata</italic> in Assiut Governorate suggest that the Cyto B gene may be used as a genetic marker to identify resistant isolates of <italic>T. annulata</italic>.