Incidence of tick-borne spotted fever group Rickettsia species in rodents in two regions in Kazakhstan

Abstract

Records on the distribution of Rickettsia spp. in their natural hosts in Central Asia are incomplete. Rodents and small mammals are potential natural reservoirs for Rickettsiae in their natural lifecycle. Studies about the maintenance of Rickettsia in wild animals are available for Western nations, but—to our knowledge—no studies and data are available in the Republic of Kazakhstan so far. The first case description of Rickettsioses in Kazakhstan was made in the 1950ies in the Almaty region and now Kyzylorda, East Kazakhstan, Pavlodar and North Kazakhstan are endemic areas. The existence of murine and endemic typhus was proven in arthropod vectors in the regions Kyzylorda and Almaty. Here we show for the first time investigations on tick-borne Rickettsia species detected by a pan-rickettsial citrate synthase gene (gltA) real-time PCR in ear lobes of small mammals (n = 624) in Kazakhstan. From all analysed small mammals 2.72% were positive for Rickettsia raoultii, R. slovaca or R. conorii. Sequencing of the rickettsial gene OmpAIV and the 23S–5S interspacer region revealed a similar heritage of identified Rickettsia species that was observed in ticks in previous studies from the region. In summary, this study proves that rodents in Kazakhstan serve as a natural reservoir of Rickettsia spp.