Species of Canidae in Russia can be infested with up to 24 different tick species; however, the frequency of different tick species infesting domestic dogs across Russia is not known. In addition, tick-borne disease risks for domestic dogs in Russia are not well quantified. The goal of this study was to conduct a nationwide survey of ticks collected from infested dogs admitted to veterinary clinics in Russian cities and to identify pathogens found in these ticks. Ticks feeding on dogs admitted to 32 veterinary clinics in 27 major cities across Russia were preserved in ethanol and submitted to a central facility for examination. After identification, each tick was evaluated for infection with known tick-borne pathogens using PCR. There were 990 individual ticks collected from 636 dogs. All collected ticks belonged to the Ixodidae (hard ticks) and represented 11 species of four genera, Dermacentor, Ixodes, Rhipicephalus and Haemaphysalis. Four most common tick species were D. reticulatus, followed by I. persulcatus, I. ricinus and R. sanguineus. Ixodes persulcatus ticks were found to be infected with 10 different pathogens, and ticks of this species were more frequently infected than either D. reticulatus or I. ricinus. Ixodes persulcatus females were also more frequently co-infected with two or more pathogens than any other tick. Pathogenic species of five genera were detected in ticks: Anaplasma centrale, A. phagocytophilum and A. marginale; Babesia canis, B. microti, B. venatorum, B. divergens, B. crassa and B. vogeli; Borrelia miyamotoi, B. afzelii and B. garinii; Ehrlichia muris, E. canis and E. ruminantum; and Theileria cervi. Anaplasma marginale, E. canis, B. crassa, B. vogeli and T. cervi were detected in I. persulcatus, and Babesia canis in D. marginatum, for the first time in Russia. Multiple ticks from four genera and 11 species of the family Ixodidae were collected from domestic dogs across Russia. These ticks commonly carry pathogens and act as disease vectors. Ixodes persulcatus ticks present the greatest risk for transmission of multiple arthropod-borne pathogens.

Alveolar echinococcosis (AE) is a rare but severe disease that affects more than 18,000 people worldwide per year. The complete sequencing of the mitochondrial genome of Echinococcus multilocularis has made it possible to study the genetic diversity of the parasite and its spatial and temporal evolution. We amplified the whole mitochondrial genome by PCR, using one uniplex and two multiplex reactions to cover the 13,738 bp of the mitogenome, and then sequenced the amplicons with Illumina technology. In total, 113 samples from Europe, Asia, , the Arctic and North America were analyzed. Three major haplogroups were found: HG1, which clustered samples from Alaska (including Saint-Lawrence Island), Yakutia (Russia) and Svalbard; HG2, with samples from Asia, North America and Europe; and HG3, subdivided into three micro-haplogroups. HG3a included samples from North America and Europe, whereas HG3b and HG3c only include samples from Europe. In France, HG3a included samples from patients more recently diagnosed in a region outside the historical endemic area. A fourth putative haplogroup, HG4, was represented by only one isolate from Olkhon Island (Russia). The increased discriminatory power of the complete sequencing of the E. multilocularis mitogenome has made it possible to highlight four distinct geographical clusters, one being divided into three micro-haplogroups in France.

Cestodes Paranoplocephala kalelai, which parasitizes in the small intestine of Myodes voles and is distributed in northern Fennoscandia, was found in six habitats in the Asian part of Russia and eastern Kazakhstan, which indicates a wider distribution of P. kalelai on the continent. Analysis of mtDNA showed that P. kalelai is characterized by significant molecular variability in Eurasia. This study complements the data on the distribution of P. kalelai and provides the first molecular data from the territory of Russia and Kazakhstan. The sequence variability of two mitochondrial genes cox1 and nad1 of P. kalelai was studied in two species of voles: gray red-backed Myodes rufocanus and northern red-backed vole Myodes rutilus. Five haplotype groups in the cox1 and nad1 gene networks were identified, and the existence of two mtDNA lines in P. kalelai outside northern Fennoscandia was confirmed. The geographical distribution of the identified haplotypes suggests that the foothills of the Altai-Sayan mountains and southern West Siberia may serve as a refugium for P. kalelai during repeated glaciations.

Cestodes Ctenotaenia marmotae are a widespread parasite of Eurasian ground squirrels. Being the only valid species of its genus, it has been recorded in ten host species from the genera Marmota and Spermophilus. Its definitive hosts live in similar ecological conditions and their area covers a wide geographical territory. Therefore, it remained unclear whether C. marmotae is a single species and how high the level of its genetic variability is. The present study analyzed the variability of two mitochondrial cestode genes from four host species from geographically distant localities. Phylogenetic analysis revealed that the newly obtained sequences form a species-level clade with already known sequences from the GenBank. Small genetic distances between the studied sequences indicate low intraspecific genetic variability within the C. marmotae, which may be a consequence of rapid expansion of the cestodes in ground squirrel species inhabiting the flat and mountain steppe landscapes in the past.