Molecular biology detection and identification for blood protozoan (Theileria spp.) in ruminants (cattle, bufalo, goat) and horse in Northern Viet Nam

Abstract

Protozoan in the genus Theileria are tick-borne parasites that have been found in a range of mammal animals. In Viet Nam, 3 species of Theileria have been reported. From June 2022 to May 2023, 2,400 EDTA blood samples were collected from ruminants (buffalo, cattle, and goat), and horse in 3 provinces in Northern Viet Nam, these samples were studied by molecular biology method for detecting and identifying Theileria spp. and their species components. Methods of nPCR and the Sanger sequencing of the 18S rDNA gene, following the sequencing analysis were applied. The studied results showed that all 4 animal types: buffalo, cattle, goat and horse were infected with Theileria spp. at a moderate prevalence (15.4%; 95%CI: 14.0-16.9). The infection rate of cattle with Theileria spp was highest (19.7%; 95%CI: 16.6-22.7), and the infection rate of goat with Theileria spp. was lowest (7.7%; 95%CI: 5.5-9.8). Results of the18S rDNA gene sequencing and analysis demonstrated that there were 5 species of Theileria, consisting of T. annulata, T. orientalis, T. buffeli, T. verlifera and T. equi, they infected in ruminants and horses in Northern Viet Nam. Of which, for the first time 3 species of T. buffeli, T. verlifera and T. equi were identified by molecular biology method and reported in Viet Nam, increasing the number of Theileria species occurring in Viet Nam from 3 to 6 species.