| Abstract: | Hemolymph was collected from adult Dermacentor andersoni Stiles that had been infected with Anaplasma marginale Theiler as nymphs. Before hemolymph was collected, the adult ticks were either incubated and unfed at 37 C for 2.5 days or fed for 6 days on sheep. Hemolymph collected from groups of 100 ticks was inoculated into susceptible splenectomized calves. Smears of hemolymph from the same groups of ticks were prepared for examination by fluorescent antibody technique. Hemolymph from incubated ticks caused anaplasmosis in 2 of 4 trials, and hemolymph from feeding ticks caused anaplasmosis in 4 of 4 trials. Moderately fluorescing bodies were demonstrated in some hemocytes from incubated ticks, whereas hemocytes from feeding ticks contained numerous clusters of brightly fluorescing bodies. Fluorescing bodies were not observed in hemocytes from control ticks. |
