Establishment and characterization of an Oklahoma isolate of @entity16451 in cultured XXXX cells.

@entity9187 @entity3966 @entity281 @entity5895 @entity73092 @entity291 @entity16451 @entity7545
@entity16451 is a @entity7545 of @entity291 worldwide. The Virginia isolate of A. marginale was propagated previously in a cell line derived from embryos of the tick, @entity3966 . The cultured Anaplasma (VA-tc) was passaged continuously for over 4 years and retained its infectivity for cattle and antigenic stability. We report herein the continuous in vitro cultivation of a second isolate of A. marginale derived from a naturally infected @entity291 in Oklahoma (OK-tc). Blood from the infected @entity291 was subinoculated into a splenectomized @entity291 and blood collected at peak @entity5895 was frozen, thawed and used as inoculum on confluent tick cell monolayers. Colonies of Anaplasma were apparent in low numbers at 9 days post exposure (PE) and @entity281 in monolayers reached 100% by 4-5 weeks PE. Cultures were passaged by placing supernatant onto fresh tick cell monolayers at a dilution of 1:5 or 1:10. By the third passage development of the OK-tc was similar to that of the VA-tc and a 1:5 dilution resulted in 100% @entity281 in 10-12 days. Inoculation of OK-tc into a splenectomized @entity291 caused clinical @entity9187 and Dermacentor ticks that fed on this @entity291 transmitted the organism to a second susceptible @entity291 . Major surface proteins (MSPs) 1-5 of the OK-tc were compared with homologous proteins present on VA-tc and the erythrocytic stage of the Oklahoma isolate. The MSPs 1, 2, 4, 5 were conserved on the OK-tc but there was evidence for structural variation in MSP3 between the cultured and erythrocytic stage of Anaplasma. MSP2 and MSP3 were the major proteins recognized by serum from infected @entity291 . Two-dimensional gels also identified positional differences between @entity73092 in MSP2 and MSP3. The OK-tc may have potential to be used as antigen for development of an improved vaccine for @entity9187 in the South Central United States.
