Molecular Epidemiology and Detection of Mutation in Cytochrome b Gene of Theileria annulata Associated with Buparvaquone Resistance in Bovines from Punjab, Pakistan

Drug resistance is an emerging international concern. The detailed knowledge on the epidemiology of bovine tropical theileriosis with respect to buparvaquone resistance is lacking in Punjab, Pakistan. During November 2022 to October 2023, a total of 400 blood samples were gathered from symptomatic cattle (n=200) and buffaloes (n=200) using a multistage cluster sampling technique belonging to the Jhang and Bhakkar districts. The samples were processed through PCR targeting the cytochrome b (cyt b) gene of Theileria annulata. A questionnaire was administered to gather data regarding disease determinants. The positivity of tropical theileriosis in Jhang and Bhakkar was 24.5% and 29%. Chi square-based analysis revealed that age, tick infestation, acaricide use, herd size and season were significantly associated common determinants of tropical theileriosis in cattle and buffaloes. Out of 107 positive samples, 86 (cattle n=54; buffalo n=32) were treated with buparvaquone, and 21 animals were non-treated (cattle n=13; buffalo n=8). Animals selected for treatment were based on parasitemia (>10%) and PCR positivity. It was observed that out of 86 animals, 72% (n=62) responded (cattle n=39; buffalo n=23) to buparvaquone and 28% (n=24) were declared resistant (cattle n=19; buffalo n=5), confirmed after amplifying 1092 base pairs of the cyt b gene. The analysis of cytb revealed point mutation at seven points including two non-synonymous point mutations. Phylogenetic insights revealed that current isolates exhibited higher homology with genotypes from India, Turkey, Iran, Egypt, Tunisia and Sudan isolated from cattle. It can be concluded that buparvaquone resistance exists in the study districts. This could be the important limiting factor for the treatment against tropical theileriosis. There is a necessity to conduct large-scale surveillance studies to develop effective control strategies to reduce the antitheilerial resistance.

To Cite This Article: Atif  FA, Arif S, Imran M and Arshad M 2025. Molecular epidemiology and detection of mutation in Cytochrome b gene of Theileria annulata associated with buparvaquone resistance in bovines from Punjab, Pakistan. Pak Vet J, 45(2): 775-782. http://dx.doi.org/10.29261/pakvetj/2025.195