Revisiting the Tams1-encoding gene as a species-specific target for the molecular detection of Theileria annulata in bovine blood samples

Tropical or Mediterranean theileriosis is a tick-borne hemoprotozoan disease that poses important health problems in cattle. The etiological agent is the apicomplexan parasite Theileria annulata that occurs around the Mediterranean basin, Middle East, and southern Asia. PCR-based assays have been developed for detecting theilerial infections, and the gene encoding an immunodominant major merozoite/piroplasm surface antigen of T. annulata (Tams1) is a commonly used genomic target. However, several studies revealed that this gene is highly polymorphic raising questions concerning the suitability of Tams1 gene-targeted primers to detect all T. annulata isolates. In this work, we re-evaluated the in silico sensitivity of previously developed primers targeting the Tams1 gene, designed novel and more comprehensive primers for its amplification, and established efficient standard and real-time PCR assays for assessing the presence or absence of T. annulata in bovine blood samples.