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A PCR-based survey of hemoprotozoa parasites detected Babesia bigemina, Theileria orientalis and Trypanosoma theileri among cattle and water buffalo in Vietnam, and a new Babesia sp. closely related to Babesia ovata was detected in cattle only. In addition, Theileria annulata and Trypanosoma evansi were not detected in both cattle and water buffalo. Phylogenetic analysis detected T. orientalis MPSP genotypes 3, 5, 7 and N3 in cattle and 5, 7, N1 and N2 in water buffalo. Additionally, water buffalo-derived T. theileri CATL sequences clustered together with a previously reported cattle-derived sequence from Vietnam. This is the first report of a new Babesia sp. in cattle, and T. orientalis MPSP genotype 7 and T. theileri in water buffalo in Vietnam.

Babesia bovis is the most virulent Babesia organism, resulting in a high mortality rate in cattle. The genetic diversity of B. bovis merozoite surface antigens (MSAs), such as MSA-1, MSA-2b, and MSA-2c, might be linked to altered immune profiles in the host animals. The present study aimed to develop type-specific PCR assays for Asian msa-1 genotypes, thereby re-analyzing the genetic diversity of msa-1 in Sri Lanka, Mongolia, and Vietnam. Specific primers were designed for nine Asian msa-1 genotypes, which had been detected based on the phylogeny constructed using msa-1 gene sequences retrieved from the GenBank database. Specificity of the type-specific PCR assays was confirmed using plasmids containing the inserts of msa-1 gene fragments that represent Asian genotypes. Furthermore, no amplicons were observed by these PCR assays when DNA samples of Babesia bigemina, Babesia ovata, Theileria annulata, Theileria orientalis, Trypanosoma evansi, Trypanosoma theileri, Anaplasma marginale, and Anaplasma bovis, and non-infected bovine blood were analyzed. In total, 109 B. bovis-positive blood DNA samples sourced from Sri Lanka (44 cattle), Mongolia (26 cattle), and Vietnam (23 cattle and 16 water buffaloes) were then screened by the type-specific PCR assays. The sequences derived from all of the PCR amplicons were phylogenetically analyzed. Out of 109 DNA samples, 23 (20 from cattle and 3 from water buffaloes) were positive for at least one genotype. In agreement with previous studies, five and four different genotypes were detected among the DNA samples from Sri Lanka and Vietnam, respectively. In contrast, four genotypes, including three novel genotypes, were detected from Mongolia. Five DNA samples were found to be co-infected with multiple genotypes. The sequences of the PCR amplicons clustered phylogenetically within the corresponding clades. These findings indicated that the type-specific PCR assays described herein are useful for the determination of genotypic diversity of the B. bovis msa-1 gene in Asia., (Copyright © 2015 Elsevier B.V. All rights reserved.)