A Targeted Next-Generation Sequencing-Informatic Approach to Define Genetic Diversity in Theileria orientalis Populations within Individual Cattle: Proof-of-Principle

摘要

Oriental theileriosis is an economically important tickborne disease of bovines, caused by some members of the complex. Currently, 11 distinct operational taxonomic units (OTUs), or genotypes, are recognized based on their major piroplasm surface protein ( ) gene sequences. Two of these genotypes (i.e., and ) are recognized as pathogenic in cattle, causing significant disease in countries of the Asia-Pacific region. However, the true extent of genetic variation and associated virulence/pathogenicity within this complex is unknown. Here, we undertook a proof-of-principle study of a small panel of genomic DNAs ( = 13) from blood samples originating from individual cattle known to harbor , in order to assess the performance of a targeted “next-generation” sequencing-informatic approach to identify genotypes. Five genotypes ( , , , , and ) were defined; multiple genotypes were found within individual samples, with dominant and minor sequence types representing most genotypes. This study indicates that this sequencing-informatic workflow could be useful to assess the nature and extent of genetic variation within and among populations of on a large scale, and to potentially employ panels of distinct gene markers for expanded molecular epidemiological investigations of socioeconomically important protistan pathogens more generally.