AbstractBackgroundTo date, 6 tick-borne rickettsiae pathogenic for humans are known to occur in Africa and 4 of them were first identified in ticks before being recognized as human pathogens.ResultsWe examined 33 and 5Amblyomma tholloniticks from African elephants in the Central African Republic and Gabon, respectively, by PCR amplification and sequencing of a part ofgltAandompAgenes of the genusRickettsia. The partial sequences ofgltAandompAgenes detected in tick in Gabon had 99.1% similarity with those ofR. heilongjiangensisand 97.1% with those ofRickettsiasp. HL-93 strain, respectively. The partialgltAandompAgene sequences detected in tick in the Central African Republic were 98.9% and 95.1% similar to those ofRickettsiasp. DnS14 strain andR. massiliae, respectively. Phylogenetic analysis showedRickettsiasp. detected in Gabon clusters withR. japonicaandR. heilongjiangensisin a phylogenetic tree based on the partialgltAandompAgenes. The genotype of theRickettsiasp. detected in the Central African Republic is close to those ofR. massiliaegroup in the phylogenetic tree based on partialgltAgene sequences, and distantly related to other rickettsiae in the tree based on partialompAgene.ConclusionThe degrees of similarity of partialgltAandompAgenes with recognized species indicate the rickettsiae detected in this study may be new species although we could only study the partial sequences of 2 genes regarding the amount of DNA that was available. We propose theRickettsiasp. detected in Gabon be provisionally named "Rickettsia sp. stain Davousti" andRickettsiasp. detected in the Central African Republic be named "Rickettsia sp.strain Uilenbergi".