A partially protective clone from Cowdria ruminantium identified by using a Salmonella vaccine delivery system.
A strategy has been developed to screen the Cowdria genome, using a Salmonella vaccine delivery system, to identify genes that code for protection-stimulating proteins. We have cloned mini-libraries of Cowdria into this Salmonella system, used the recombinant bacteria to immunize outbred mice, and then challenged them after two weeks with a lethal dose of Cowdria. When one of these mini-libraries was tested in a group of 5 mice, one mouse lived much longer than the others. The experiment was repeated with each of the clones from the mini-library being tested individually in 10 mice, and one mouse survived the challenge. This clone has been tested repeatedly in larger groups of mice and is proven to protect 14% of outbred mice against a lethal Cowdria challenge.
Onderstepoort Veterinary Institute, South Africa. kelly@ovisun.ovi.ac.za
K A
KA
Brayton
M
M
van der Walt
S W
SW
Vogel
B A
BA
Allsopp
D000818:Animals; D001428:Bacterial Vaccines; D003001:Cloning, Molecular; D016995:Ehrlichia ruminantium / Q000235:genetics / Q000276:immunology*; D005260:Female; D006357:Heartwater Disease / Q000276:immunology* / Q000517:prevention & control; D051379:Mice; D019151:Peptide Library; D012475:Salmonella; D013997:Time Factors; D014614:Vaccines, Synthetic
D001428:Bacterial Vaccines; D019151:Peptide Library; D014614:Vaccines, Synthetic