title: First isolation of Rickettsia helvetica from Ixodes ricinus ticks in France.
abstract: Two rickettsial isolates recovered from Ixodes ricinus ticks in Puy-de-Dôme (Central France) were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blot immunoassay, restriction fragment length polymorphism analysis, and sequencing of a portion of the citrate-synthase gene. By these methods, the isolates appeared to be identical to a member of the spotted fever group rickettsiae, Rickettsia helvetica. This first isolation of Rickettsia helvetica in France has epidemiologic importance; a serosurvey on Mediterranean spotted fever conducted previously in Puy-de-Dôme, where the infection is not endemic, demonstrated a high seroprevalence of nonspecific antibodies directed against spotted fever group rickettsiae lipopolysaccharides, and thus the possibility of infection due to a rickettsia different from Rickettsia conorii was suggested. The isolation of Rickettsia helvetica in anthropophilic ticks in the same area further supports this hypothesis.
authors.affiliation: Unité des Rickettsies, Université de la Méditerranée, CNRS UPRES A 6020, Faculté de Médecine, Marseille, France.
authors.forename: P
authors.initials: P
authors.lastname: Parola
authors.forename: L
authors.initials: L
authors.lastname: Beati
authors.forename: M
authors.initials: M
authors.lastname: Cambon
authors.forename: D
authors.initials: D
authors.lastname: Raoult
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001907:Boutonneuse Fever / Q000453:epidemiology / Q000382:microbiology; D002950:Citrate (si)-Synthase / Q000235:genetics; D004269:DNA, Bacterial / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D005602:France / Q000453:epidemiology; D006801:Humans; D018884:Ixodes / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D012281:Rickettsia / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D004269:DNA, Bacterial; D002950:Citrate (si)-Synthase