Culture Isolate of from a Tick.

Although the cat flea, , has been identified as the primary vector of , additional flea, tick, mite, and louse species have also been associated with this bacterium by molecular means; however, the role of these arthropods in the transmission of has not been clarified. Here, we succeeded in culture isolation of from a host-seeking castor bean tick, , the most common tick in Slovakia. The bacterial isolation was performed on XTC-2 cells at 28 °C using the shell-vial technique. An evaluation of the growth properties was performed for both the XTC-2 and Vero cell lines. We observed in the infected host cells microscopically by Gimenez staining and immunofluorescence assay. The isolate was purified by gradient ultracentrifugation and visualized by electron microscopy. Fragments of the genes A, A, B, A, B, 4, E, and were amplified and compared with the corresponding sequences of the type strain URRWXCal2 and other culture -isolated strains. We did not detect any nucleotide polymorphisms; however, plasmid pRFδ, characteristic of the standard strain, was absent in our isolate. Herein, we describe the first successful isolation and characterization of a tick-derived strain "Danube", obtained from an nymph.