Molecular detection and characterization of Theileria species in the Philippines

Theileriosis is a tick-borne disease of domestic and wild animals that cause devastating economic loss in livestock in tropical and subtropical regions. Theileriosis is not yet documented in the Philippines as compared to babesiosis and anaplasmosis which are considered major tick-borne diseases that infect livestock in the country and contribute major losses to the livestock industry. The study was aimed to detect Theileria sp. at genus level in blood samples of cattle using polymerase chain reaction (PCR) assay. Specifically, it determined the phylogenetic relationship of Theileria species affecting cattle in the Philippines to other Theileria sp. registered in the GenBank. A total of 292 blood samples of cattle that were collected from various provinces were used. Theileria sp. was detected in 43/292 from the cattle blood samples using PCR assay targeting the major piroplasm surface protein (MPSP) gene. DNA sequence showed high similarity (90-99%) among the reported Theileria sp. isolates in the GenBank and the Philippine isolates of Theileria. Phylogenetic tree construction using nucleotide sequence classified the Philippine isolates of Theileria as benign. However, nucleotide polymorphism was observed in the new isolate based on nucleotide sequence alignment. It revealed that the new isolate can be a new species of Theileria.