Molecular occurrence and genetic identification of Babesia spp. and Theileria spp. in naturally infected cattle from Thailand.

Piroplasm including Babesia spp. and Theileria spp. in cattle can cause illness that affects livestock productivity, resulting in significant production losses, especially in tropical and subtropical regions such as Thailand. This study aimed to investigate the prevalence of bovine piroplasms and to identify these blood parasites based on the 18S ribosomal RNA gene in cattle in the northeastern part of Thailand. Piroplasmid infections among beef and dairy cattle were examined using nested PCR. Furthermore, amplicon DNA was sequenced and analyzed, and a phylogenetic tree was constructed to determine the genetic diversity and relationships of the parasite in each area. A total of 141 out of 215 (65.6%) cattle were positive for infection with Babesia or Theileria. DNA analysis revealed that infection by Babesia bigemina, Babesia bovis, Theileria orientalis, Theileria sinensis, and Theileria sp. were common piroplasms in cattle in this region, with a high sequence shared identity and similarity with each other and clustered with isolates from other countries. This study provides information on the molecular epidemiology and genetic identification of Babesia spp. and Theileria spp. in beef and dairy cattle to provide a better understanding of piroplasm infection in cattle in this region, which will help control these blood parasites. Moreover, this is the first report identifying T. sinensis circulating among Thai cattle.