Rickettsia sp. closely related to Rickettsia raoultii (Rickettsiales: Rickettsiaceae) in an Amblyomma helvolum (Acarina: Ixodidae) tick from a Varanus salvator (Squamata: Varanidae) in Thailand.

An engorged female Amblyomma helvolum Koch tick was removed from an adult Varanus salvator Laurenti lizard during field collection in Thailand. After using polymerase chain reaction to amplify three genes (16S rDNA, gltA, and OmpA), we discovered the presence of a Rickettsia sp. of the Spotted Fever Group. Phylogenetic analysis revealed that this Rickettsia sp. is closely related to Rickettsia raoultii Mediannikov. Therefore, we report herein for the first time the detection of a novel Spotted Fever Group Rickettsia in an Amblyomma helvolum from a Varanus salvator in Thailand.