Cultivation of Anaplasma marginale from cattle in a Dermacentor cell line.

A tick cell line derived from Dermacentor variabilis (RML-15) was inoculated with bovine RBC infected with Anaplasma marginale. Two hours after inoculation, numerous RBC were phagocytized by the tick cells. After one passage of the cell culture, numerous groups of Anaplasma-like particles were seen in the tick cell cytoplasm. Increased numbers of Anaplasma-like particles also were present. Seemingly, Anaplasma can multiply in tick cells.