Rickettsia aeschlimannii sp. nov., a new spotted fever group rickettsia associated with Hyalomma marginatum ticks.

We formally propose the name Rickettsia aeschlimannii sp. nov. for a new spotted fever group (SFG) rickettsia, strain MC16T, isolated from Hyalomma marginatum marginatum ticks collected in Morocco. This organism shows a typical rickettsial morphology when analyzed by electron microscopy. After characterization by serotyping, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western immunoblotting, PCR-restriction fragment length polymorphism (RFLP), pulsed-field gel electrophoresis, and 16S rDNA sequencing, this organism was found to be different from all of the recognized SFG rickettsiae. Identical PCR-RFLP profiles have, however, been found in H. marginatum marginatum from Portugal and H. marginatum rufipes from Zimbabwe, which suggests that the distribution of this rickettsia reaches from the Mediterranean to southern Africa.