Molecular detection and genetic diversity of Babesia canis in ticks and pet dogs in Lithuania

Babesia canis, a haemoprotozoan parasite, is the main cause of a tick-borne infection of dogs-canine babesiosis. During the last decade, a spread of canine babesiosis due to B.canis to the previously non-endemic areas has been reported in Europe. Expansion of B.canis in Baltic countries is associated mainly with the expanding range of the main vector – Dermacentor reticulatu sticks and international travel. Genetic variability and antigenic variation are important mechanisms for the survival of Babesia parasites in their vertebrate hosts. Differences in the virulence of B.canis are associated with observed genetic heterogeneity among B.canis strains. We have investigated the prevalence of B.canis in D.reticulatus ticks along its current distribution range in Lithuania and the genetic diversity of B.canis strains isolated from ticks and naturally infected dogs. Partial regions of the 18S rRNA and Bc28.1 gene of B.canis were amplified through PCR assays, followed by PCR-RFLP and sequence analysis for molecular characterization of strains. B.canis was detected in 1.2% (26/2259) of D. reticulatus ticks with the prevalence varied in different locations from 0% to 11%. The molecular analysis indicates the presence of genetically heterogenic B.canis strains in Lithuania: three genotypes were detected based on 18S rRNR gene, while thirteen Bc28.1 gene sequence variants which divided into four genetically distinct groups were identified. Our findings on the genetic diversity of B. canis strains in Lithuania can be useful for the development of a polyvalent vaccine, assessing its potential for use and for predicting the risk of complicated diseasesBiologijos katedraVytauto Didžiojo universiteta