A preliminary molecular survey of Babesia divergens and first evidence of Theileria annulata in cattle from Saudi Arabia

BACKGROUND AND AIM: Babesia divergens causes human babesiosis in Europe where the parasite utilizes cattle as animal reservoir and Ixodes ricinus as tick vector. Importation of infected animals and passive carriage of infected ticks through migratory birds can lead to tick/pathogen geographic expansion and emergence of diseases in naïve land. Given the information that Saudi Arabia imports cattle from the European countries and that two global bird flyways pass through the country geographic coordinates, we speculate that B. divergens might be introduced into the Kingdom. Therefore, the aim of this preliminary study was to molecularly detect and characterize B. divergens and other piroplasms (including Theileria spp.) in cattle from Taif district, Kingdom of Saudi Arabia. MATERIALS AND METHODS: Blood samples from 20 cattle residing Taif district were collected, and polymerase chain reaction tested using wide and species-specific primers. Amplicons from a positive genus-wide reaction were purified, sequenced, and analyzed. Phylogenetic trees were constructed, and similarity to existing GenBank zoonotic piroplasms was also assessed. RESULTS: All samples were negative for B. divergens, and only one sample proved positive for Theileria annulata in a wide reaction. Phylogeny clustered our strain with T. annulata from Spanish dog and another one detected in a cow from France. BLAST analysis showed genetic distance from zoonotic piroplasms with identity ranged from 88% to 91%. CONCLUSION: Although B. divergens was not detected, we are not able to rule out or affirm the existence of the pathogen in the country. On the other hand, identifying T. annulata strain with a southern European origin strongly supports our speculation that bovine zoonotic Babesia might be introduced into KSA. This study is not only the first molecular survey of B. divergens but also the first report of the molecular identity of T. annulata in Saudi Arabia. A national-wide bovine and tick surveillance are needed to further prove our speculation.