Rickettsia honei sp. nov., the aetiological agent of Flinders Island spotted fever in Australia

Abstract

The name Rickettsia honei, strain RBT, has been proposed for a unique spotted fever group (SFG) agent which is pathogenic for humans. This agent has previously been compared to the other SFG agents and was shown to be distinct in protein structure by SDS-PAGE and by immunoblotting. Genetic comparisons of the 16S rRNA, rompA, gltA and the 17 kDa antigen genes with the other SFG rickettsiae confirmed the phylogenetic distance between R. honei and the previously described species. Genetically, Rickettsia honei is more closely related to the Thai tick typhus (TT-118) rickettsia than to any other member of the SFG. Indeed, it is proposed that TT-118 is a strain of R. honei which was previously isolated in Thailand. These results elucidate the presence of a unique SFG rickettsial species in Australasia.