Anaplasma phagocytophilum in European bison (Bison bonasus) and their ticks from Lithuania and Poland

The increasing population of European bison (Bison bonasus) can contribute to the prevalence of zoonotic pathogens. The aim of the present study was to assess the presence of A. phagocytophilum infection in European bison tissues as well as ticks removed from European bison in Lithuania and Poland. A further objective of this work was to compare the detected A. phagocytophilum strains. A total of 85 tissue samples (spleen) of European bison and 560 ticks belonging to two species, Ixodes ricinus (n = 408) and Dermacentor reticulatus (n = 152) were tested. DNA of A. phagocytophilum was detected based on RT-PCR in 40% of the European bison samples, 8.8% of the I. ricinus and 5.9% of the D. reticulatus ticks. Analysis of the obtained partial 16S rRNA gene sequences of A. phagocytophilum revealed the presence of three variants with two polymorphic sites. Furthermore, phylogenetic analysis with partial msp4 gene sequences grouped A. phagocytophilum variants into three clusters. This study revealed that the groEL gene sequences of A. phagocytophilum from European bison and their ticks grouped into ecotype I and only one sequence from Lithuanian European bison belonged to ecotype II. The results of the present study indicated that European bison may play a role as a natural reservoir of A. phagocytophilum.