Persistence of tick-derived Anaplasma marginale in cultured bovine turbinate and endothelial cells.
Anaplasma marginale from salivary glands of Dermacentor andersoni was used to inoculate monolayers of bovine turbinate and endothelial cells. Monolayers were passaged at 2 or 4 week intervals and monitored with light and electron microscopy and with an A. marginale-specific DNA probe. Intracellular inclusions were observed in turbinate cells after 2-4 weeks. The number of inclusion-bearing cells increased over 1-2 weeks and gradually disappeared. A radiolabeled fragment from within the msp1 beta gene of the erythrocytic stage of A. marginale hybridized to DNA extracted from bovine turbinate cell cultures as late as 7 weeks post inoculation (passage 4). Individual rickettsiae were observed with electron microscopy in samples taken at this time. Susceptible calves inoculated with suspect cultures did not develop clinical anaplasmosis but did develop significant antibody titers as detected with ELISA. DNA from endothelial cell cultures at 9 weeks post inoculation also bound the Anaplasma-specific DNA probe. Anaplasma marginale from salivary glands of D. andersoni appears to persist in cultured bovine turbinate and endothelial cells but typical development and infectivity for bovines do not occur.
Blouin
E F
EF
College of Veterinary Medicine, Oklahoma State University, Stillwater 74078.
Kocan
K M
KM
Murphy
G L
GL
Ge
N
N
D000709:Anaplasma / Q000502:physiology*; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology*; D002478:Cells, Cultured; D008854:Microscopy, Electron; D013987:Ticks / Q000469:parasitology*