title: Comparative antigenic analysis of spotted fever group rickettsiae from Israel and other closely related organisms.
abstract: Spotted fever rickettsiosis in Israel has been considered as possibly somewhat more severe than boutonneuse fever, from which it also differs in having a very low proportion of cases with a tick-inoculation site eschar. This investigation was undertaken to determine whether the Israeli spotted fever group (SFG) rickettsiae differed sufficiently from Rickettsia conorii to be considered as a distinct species. Strains of Rickettsia conorii from Morocco and South Africa, four SGF rickettsial isolates from Israel, one from Russia, and one from Zimbabwe were compared by microimmunofluorescence serotyping, Western immunoblotting, monoclonal antibody reactivity, and polymerase chain reaction amplification of the repeat domain of the rickettsial outer membrane protein A (rOmpA). All are strains and isolates of R. conorii, yet there is considerable molecular and antigenic diversity of both rOmpA and rickettsial outer membrane protein B (rOmpB) among them. The rOmpA gene of the Israeli isolates and the Astrakhan strain from Russia is estimated to encode 15 rOmpA repeat units as compared with 10 for the South African strain and six for the strains from Morocco and Zimbabwe. The Israeli SFG rickettsial strains appear to be R. conorii, a species with substantial antigenic and genetic diversity. The Israeli strains appear to fall within the limit previously described for the genetic and antigenic diversity of R. conorii.
authors.affiliation: Department of Pathology, University of Texas Medical Branch, Galveston, USA.
authors.forename: D H
authors.initials: DH
authors.lastname: Walker
authors.forename: H M
authors.initials: HM
authors.lastname: Feng
authors.forename: J I
authors.initials: JI
authors.lastname: Saada
authors.forename: P
authors.initials: P
authors.lastname: Crocquet-Valdes
authors.forename: S
authors.initials: S
authors.lastname: Radulovic
authors.forename: V L
authors.initials: VL
authors.lastname: Popov
authors.forename: E
authors.initials: E
authors.lastname: Manor
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000940:Antigenic Variation; D000942:Antigens, Bacterial / Q000032:analysis*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001483:Base Sequence; D015153:Blotting, Western; D017931:DNA Primers / Q000737:chemistry; D004269:DNA, Bacterial / Q000032:analysis / Q000737:chemistry; D005455:Fluorescent Antibody Technique; D014644:Genetic Variation; D006801:Humans; D007557:Israel; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012091:Repetitive Sequences, Nucleic Acid; D012281:Rickettsia / Q000145:classification / Q000235:genetics / Q000276:immunology*; D012692:Serial Passage; D012703:Serotyping
chemical_list: D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D017931:DNA Primers; D004269:DNA, Bacterial