Confirmation that <i>Rickettsia helvetica</i> sp. nov. Is a Distinct Species of the Spotted Fever Group of Rickettsiae

We propose the name <i>Rickettsia helvetica</i> sp. nov. for a rickettsial serotype of unknown pathogenicity isolated in 1979 in Switzerland from <i>Ixodes ricinus</i> ticks and designated the Swiss agent. The growth characteristics and the results of microimmunofluorescence serologic typing, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blotting (immunoblotting) with specific mice sera, and a polymerase chain reaction followed by restriction fragment length polymorphism analysis confirmed previously reported preliminary findings which suggested that this rickettsia, to which a name was given provisionally, does represent a new member of the spotted fever group of rickettsiae. The type strain is C3 (Reference Center for Rickettsioses, Marseille, France).