Immunogenicity of Ehrlichia ruminantium grown in tick cell lines.
Ehrlichia (previously Cowdria) ruminantium, the pathogen which causes heart-water in domestic and wild ruminants, can now be propagated in cell lines from one vector (Amblyomma variegatum) and five non-vector (Ixodes scapularis, I. ricinus, Boophilus decoloratus, B. microplus and Rhipicephalus appendiculatus) tick species. E. ruminantium isolates from West and South Africa and the Caribbean vary in their cell line preference, growth patterns and immunogenic capability. In laboratory trials, certain combinations of tick cell line and E. ruminantium isolate were highly immunogenic in sheep. These trial vaccines were grown under specific in vitro conditions and administered as a single intravenous dose of freshly harvested whole, live culture. Following immunisation and subsequent exposure to virulent E. ruminantium, protected sheep showed no clinical response and a range of serological responses.
Centre for Tropical Veterinary Medicine, University of Edinburgh, Easter Bush, Roslin, Midlothian EH25 9RG, Scotland, UK. L.Sakyi@ed.ac.uk
Lesley
L
Bell-Sakyi
Edith
E
Paxton
Paul
P
Wright
Keith
K
Sumption
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D002460:Cell Line; D016995:Ehrlichia ruminantium / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D006357:Heartwater Disease / Q000276:immunology / Q000382:microbiology* / Q000635:transmission; D007114:Immunization / Q000662:veterinary; D026863:Ixodidae / Q000382:microbiology*; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology / Q000382:microbiology* / Q000635:transmission; D017282:Tick-Borne Diseases / Q000276:immunology / Q000382:microbiology / Q000635:transmission / Q000662:veterinary*
D000907:Antibodies, Bacterial