Ixodes persulcatus Schulze frequently bite humans but little is known about the presence and distribution of rickettsial agents in this tick. Questing flat adult I. persulcatus ticks (n=88) were collected from three villages, Vedrovo, Ustig, and Vytegorskii, in the Vologda Region in Northeast Russia. Through specific PCR amplification of the 16S rDNA gene and DNA sequencing, the uncultured novel pathogenic rickettsial agent 'Montezuma' was detected in 35.3%, 28.6%, and 36% of the ticks from Vedrovo, Ustig, and Vytegorskii, respectively. Both male and female ticks were infected. Sequences of the 16S rDNA PCR amplicon showed 100% homology to GenBank sequences for agent 'Montezuma' previously detected first in febrile patients and I. persulcatus ticks in the Khabarovsk Region in Eastern Russia. PCR amplification of the citrate synthase (gltA) gene using conserved Rickettsia primers detected DNA in one female tick from Vytegorskii. This amplicon's sequence showed greatest homology to the gltA gene of "Candidatus Rickettsia tarasevichiae", previously detected in I. persulcatus ticks from the Southern Ural and Western and Eastern Siberia, and to a slightly lesser extent to Rickettsia canadensis, previously described in Haemaphysalis leporispalustris ticks from North America. These results suggest that 'Montezuma' agent is widely distributed in Russia and may be a common cause of human illness that are not presently recognized as rickettsial infections.
Species 1: Rickettsiales Rickettsiaceae Rickettsia tarasevichiae
Species 2: Acari Ixodidae Ixodes persulcatus (taiga tick)
Keywords: rickettsiae, Montezuma agent
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