Molecular detection and phylogenetic analysis of Theileria annulata in water buffaloes based on the cytochrome b gene

Muayad, Mujtaba; Ali, Mansoor

doi:10.29079/qjvms.2026.170525.1179

Molecular detection and phylogenetic analysis of Theileria annulata in water buffaloes based on the cytochrome b gene

Document Type : Research Paper

Authors

Mujtaba Muayad ¹

Mansoor Ali ²

¹ College of Veterinary Medicine, University of Al-Qadisiyah

² college of veterinary medicine, university AL-Qadisiyah

https://doi.org/10.29079/qjvms.2026.170525.1179

Abstract

tropical theileriosis is a tick-transmitted disease that leads to considerable economic losses in livestock production in endemic areas. Although it is known that cattle are more resistant, information on whether Iraqi buffaloes also carry T. annulata is limited based on molecular studies. This study was conducted to detect T. annulata in naturally infected water buffaloes in Iraq by using the cytochrome b gene as a genetic marker and to examine its differences from other reported sequences.
Ninety-four buffalo blood samples were collected from September through December 2025 after the buffaloes had been clinically suspected of theileriosis. After Genomic DNA extracted, the cytochrome b gene of T. annulata was amplified using polymerase chain reaction (PCR). The resulting amplicons were sequenced and aligned with reference sequences stored in GenBank. A maximum-likelihood phylogenetic approach was then used to perform phylogenetic inference. PCR analysis confirmed T. annulata infection in 16 of 94 buffalo samples (17.02%). Sequence analysis showed high similarity (97.58–100%) between Iraqi isolates and previously reported global strains. Phylogenetic analysis indicated that Iraqi isolates clustered within the T. annulata clade and had close genetic relationships with isolates from several countries. The study confirms the presence of T. annulata in Iraqi buffaloes and emphasizes the usefulness of the cytochrome b gene as accurate molecular detection and phylogenetic analysis. These findings enhance understanding of the molecular epidemiology of tropical theileriosis in Iraq.

Keywords

Theileria annulata

cytochrome b

water buffalo