New Rickettsiae in Ticks Collected in Territories of the Former Soviet Union

Rickettsiae are obligate intracellular gramnegative bacteria associated with arthropod vectors, ticks, mites, and insects that, while feeding, can transmit Rickettsiae to animals and humans. The rickettsioses have characteristic clinical features, including fever, headache, maculopapular eruption, and sometimes eschar formation (primary lesion). The number of representatives of the genus Rickettsia has increased over the last decades as a result of improved cell culture isolation and agent identification techniques (1). Sequence comparison of gene coding for citrate synthase (gltA) (2), rOmpA outer membrane protein (ompA) (3), and 16S rRNA (4) has become the most reliable method of identifying Rickettsiae (5-8). We describe polymerase chain reaction (PCR) amplification and sequence determination to identify Rickettsiae in naturally infected ixodid ticks in three regions of Russia endemic for tickborne rickettsioses.