Molecular detection of Borrelia theileri in cattle in Korea

Abstract

Bovine borreliosis, caused by <i>Borrelia theileri</i> which is transmitted via hard tick bites, is associated with mild clinical symptoms, such as fever, lethargy, hemoglobinuria, anorexia, and anemia. <i>Borrelia theileri</i> infects various animals, such as cattle, deer, horses, goats, sheep, and wild ruminants, in Africa, Australia, and South America. Notably, no case of <i>B. theileri</i> infection has been reported in Korean cattle to date. In this study, 101 blood samples were collected from a Korean indigenous cattle breed, among which 1.98% tested positive for <i>B. theileri</i> via nested PCR. The obtained sequences exhibited high homology with <i>B. theileri</i> strains identified in other regions. Phylogenetic analysis of 16S rRNA confirmed the <i>B. theileri</i> group affiliation; however, flagellin B sequences exhibited divergence, potentially due to regional evolutionary differences. This study provides the first molecular confirmation of <i>B. theileri</i> infection in Korean livestock. Further isolation and nucleotide sequence analyses are necessary to better understand the presence of <i>B. theileri</i> strains in cows in Korea.