title: A subset of Cowdria ruminantium genes important for immune recognition and protection.
abstract: Cowdria ruminantium causes the tick-borne rickettsial disease of heartwater, which is devastating to livestock production in sub-Saharan Africa. Current diagnosis and control methods are inadequate. We have identified and sequenced a subset of genes encoding recombinant antigens recognized by antibody and peripheral blood mononuclear cells from immune ruminants. The identified genes include many with significant similarity to those of Rickettsia prowazekii, genes predicted to encode different outer membrane proteins and lipoproteins and a gene containing an unusual tandem repeat structure. Evidence is presented for immune protection by recombinant antigens in a mouse model of C. ruminantium infection. These data identify new recombinant antigens for evaluation in vaccines and diagnostic tests to control heartwater.
authors.affiliation: Department of Pathobiology, University of Florida, Gainesville, FL, USA. barbeta@mail.vetmed.ufl.edu
authors.forename: A F
authors.initials: AF
authors.lastname: Barbet
authors.forename: W M
authors.initials: WM
authors.lastname: Whitmire
authors.forename: S M
authors.initials: SM
authors.lastname: Kamper
authors.forename: B H
authors.initials: BH
authors.lastname: Simbi
authors.forename: R R
authors.initials: RR
authors.lastname: Ganta
authors.forename: A L
authors.initials: AL
authors.lastname: Moreland
authors.forename: D M
authors.initials: DM
authors.lastname: Mwangi
authors.forename: T C
authors.initials: TC
authors.lastname: McGuire
authors.forename: S M
authors.initials: SM
authors.lastname: Mahan
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology; D001428:Bacterial Vaccines / Q000276:immunology; D002417:Cattle; D002455:Cell Division / Q000276:immunology; D002474:Cell-Free System / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D016995:Ehrlichia ruminantium / Q000235:genetics* / Q000276:immunology; D005798:Genes, Bacterial / Q000235:genetics*; D006357:Heartwater Disease / Q000276:immunology / Q000382:microbiology / Q000401:mortality; D007106:Immune Sera / Q000276:immunology; D007107:Immune System / Q000276:immunology* / Q000382:microbiology; D008214:Lymphocytes / Q000166:cytology / Q000276:immunology / Q000382:microbiology; D051379:Mice; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D017422:Sequence Analysis, DNA; D012756:Sheep; D015996:Survival Rate; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D004269:DNA, Bacterial; D007106:Immune Sera