The aim of this research is to study the distribution, species diversity, and genetic variability of rickettsiae in Dermacentor spp. ticks from Western Siberia and Northern Kazakhstan. Thus, samples from 571 Dermacentor ticks (406 individuals of Dermacentor reticulatus, 136 Dermacentor nuttalli, 21 Dermacentor marginatus, and 8 Dermacentor silvarum) have been examined for the presence of Rickettsia spp. DNA using nested PCR. The rickettsial species have been determined by species-specific PCR and/or sequencing of gltA gene fragments. For a number of R. raoultii samples, the sequences of the ompA (3266 bp) and ompB (4852 bp) gene fragments have been additionally determined. The examined ticks carry DNA of four Rickettsia species and a new genotype Rickettsia spp. Kos-97-Dr, which cannot be assigned to any known species. All tick species are most commonly infected with R. raoultii; the infection rate varies from 47.0 to 86.8%. Rickettsia sibirica DNA has been found in 16.1–45.7% of D. nuttalli from three sites in the Republic of Altai. DNAs of Rickettsia aeschlimannii, Rickettsia aeschlimannii-like, “Candidatus Rickettsia tarasevichiae,” and a new genotype Rickettsia sp. Kos-97-Dr have been found sporadically in D. reticulatus and D. marginatus. Based on analysis of the gltA gene fragment, seven haplotypes of R. raoultii have been identified; four of them correspond to previously described genotypes. The analysis of long fragments of the ompA and ompB genes of R. raoultii samples revealed the presence of three genetic groups corresponding to different genotypes for the gltA gene. Thus, Dermacentor spp. carry both typical and atypical species of Rickettsia spp. The existence of natural foci of Siberian tick typhus in the Republic of Altai has been demonstrated. Based on the analysis of the variable surface protein genes and conserved gltA gene, the existence of three genetic groups of R. raoultii has been shown.

本研究的目的是研究皮肤病立克次体的分布、物种多样性和遗传变异性。来自西西伯利亚和哈萨克斯坦北部的蜱虫。因此，我们对 571 只皮肤蜱（406 只网状皮肤蜱、136 只Nutalli 皮肤蜱、21 只边缘皮肤蜱和 8 只森林皮肤蜱）的样本进行了立克次体属检查。使用巢式 PCR 进行 DNA 检测。立克次体种类已通过物种特异性 PCR 和/或gltA基因片段测序来确定。对于许多R. raoultii样品，还确定了ompA (3266 bp) 和ompB (4852 bp) 基因片段的序列。所检查的蜱携带四种立克次体物种的 DNA 和一种新基因型立克次体属。Kos-97-Dr，无法归属于任何已知物种。所有蜱种最常感染R. raoultii；感染率从47.0%到86.8%不等。在阿尔泰共和国三个地点的D. nuttalli中，16.1–45.7% 的西伯利亚立克次体 DNA 被发现。埃氏立克次体、类立克次体、“ Candidatus Rickettsia tarasevichiae”和新基因型立克次体 sp.的 DNA 。Kos-97-Dr 已在D. reticulatus和D. marginatus中零星发现。基于gltA基因片段的分析，已经鉴定出R. raoultii的七种单倍型；其中四个对应于先前描述的基因型。对R. raoultii样品的ompA和ompB基因长片段的分析揭示了对应于gltA基因不同基因型的三个遗传组的存在。因此，Dermacentor spp。携带典型和非典型立克次体属物种。已证实阿尔泰共和国存在西伯利亚蜱斑疹伤寒自然疫源地。基于可变表面蛋白基因和保守gltA基因的分析，已经表明R. raoultii存在三个遗传群体。