Description and life-cycle of Taenia lynciscapreoli sp n. (Cestoda, Cyclophyllidea)

A new species of tapeworm, Taenia lynciscapreoli sp. n. (Cestoda, Cyclophyllidea), is described from the Eurasian lynx (Lynx lynx), the main definitive host, and the roe deer (Capreolus capreolus and C. pygargus), the main intermediate hosts, from Finland and Russia (Siberia and the Russian Far East). The new species was found once also in the wolf (Canis lupus) and the Eurasian elk/moose (Alces alces), representing accidental definitive and intermediate hosts, respectively. The conspecificity of adult specimens and metacestodes of T. lynciscapreoli sp. n. in various host species and regions, and their distinction from related species of Taenia, was confirmed by partial nucleotide sequences of the mitochondrial cytochrome c oxidase subunit 1 gene. Morphologically, T. lynciscapreoli sp. n. can be separated unambiguously from all other species of Taenia by the shape of its large rostellar hooks, particularly the characteristically short, wide and strongly curved blade. If the large rostellar hooks are missing, T. lynciscapreoli may be separated from related species by a combination of morphological features of mature proglottids. It is suggested that T. lynciscapreoli has been present in published materials concerning the tapeworms of L. lynx and L. pardinus in Europe, but has been misidentified as Taenia pisiformis (Bloch, 1780). Taenia lynciscapreoli sp. n. has not been found in lynx outside the range of roe deer, suggesting a transmission pathway based on a specific predator-prey relationship. The present study applies a novel, simple approach to compare qualitative interspecific differences in the shape of rostellar hooks.Peer reviewe

Echinococcus across the north : Current knowledge, future challenges

Foodborne Parasites in Cold ClimatesAbstract Zoonotic Echinococcus spp. cestodes are present in almost all circumpolar nations, and have historically posed a risk to health of indigenous as well as other northern residents. However, surveillance data on both alveolar (AE) and cystic (CE) echinococcosis remains incomplete throughout the circumpolar region: Russia, Fennoscandia, Iceland, Greenland, Canada and Alaska (USA). Prevalence of Echinococcus spp. varies considerably in definitive canid hosts, animal intermediate hosts and accidental hosts like humans. Yet despite the high prevalence reported in canids in some geographic locations, human AE and CE are much less common than in endemic Asian and central European countries. This paper explores knowledge gaps and future challenges posed by Echinococcus spp. in eight circumpolar countries, a region where rapid environmental and social change are rewriting the boundaries, transmission, and impact of many pathogens, including zoonotic Echinococcus spp. Genotypes G6, G8 and G10 of Echinococcus canadensis are causative agents of human CE and have been identified in sylvatic (wild animal) and synanthropic (ecological association with humans) cervid-canine life cycles in the following northern regions: Alaska and northern Canada - G8 and G10; northern Russia - G6, G8, G10; and Fennoscandia - G10 in Finland - with no recent reports from Norway or Sweden. Echinococcus multilocularis, which causes AE, has been identified in a sylvatic arvicoline rodent-canine lifecycle in Alaska, Canada, Russia, Sweden and Svalbard (Norway). Asian, Mongolian, European and North American strains of E. multilocularis are found in Russia, with the North American N1 strain predominating in the north. The N1 strain is also found in Alaska, as well as Svalbard, whilst Asian strains have been identified in western Alaska. Central North American (N2) strain and European-type strains of E. multilocularis are present in Canada. Typing of the strain in Sweden is still pending. Individual human cases of AE with N2 and European-type strains are reported in North America, as well as multiple cases with Asian strains in Russia and historically on St Lawrence Island, Alaska (although genotyping of human cases was not available at the time). Echinococcus spp. have not been detected in Greenland and have been eliminated from Iceland. The predominance of E. multilocularis N1 strain and E. canadensis genotypes, in regions with high prevalence in definitive hosts yet low incidence of human AE and CE, suggests that these genotypes have lower zoonotic potential and pathogenicity than European and Asian strains of E. multilocularis and livestock genotypes of E granulosus sensu stricto. The continued monitoring of the emergence of Echinococcus genotypes within definitive and intermediate hosts, as well as people, is needed to assess the impact on public health risk, since the introduction of other genotypes could have serious repercussions. Lastly, determining risk factors and source attribution for human cases, including the possibility of food and waterborne transmission and the likelihood of autochthonous transmission, remain challenges.Peer reviewe

Specific status of Echinococcus canadensis (Cestoda Taeniidae) inferred from nuclear and mitochondrial gene sequences

The specific status of Echinococcus canadensis has long been controversial, mainly because it consists of the mitochondrial lineages G6, G7, G8 and G10 with different host affinity: G6 (camel strain) and G7 (pig strain) with domestic cycles and G8 (cervid strain) and G10 (Fennoscandian cervid strain) with sylvatic or semi-domestic cycles. There is an argument whether the mitochondria] lineages should be recognised as separate species which correspond to the biological or epidemiological aggregation. In the present study, the specific status of E. canadensis was investigated using mitochondrial DNA and single copy nuclear DNA markers. Nucleotide sequences of complete mitochondrial cytochrome c oxidase subunit 1 (cox1) and partial nuclear phosphoenolpyruvate carboxykinase (pepck) and DNA polymerase delta (pold) were determined for 48 isolates of E. canadensis collected from different hosts in a wide range of regions. The mitochondrial phylogeny of cox1 showed that all the isolates were clearly divided into three clades corresponding to G6/G7, G8 and G10. Five and three alleles were confirmed at pepck and pold loci, respectively. These alleles were generally divided into two groups corresponding to G6/G7 or G8 and G10. However, allele sharing was confirmed among individuals belonging to different lineages. The allele sharing occurred primarily in regions where different mitochondrial DNA lineages were found in sympatry. The resultant nuclear mitochondrial discordance suggests the genetic exchangeability among E. canadensis isolates belonging to different lineages. An apparently mosaic parasite fauna that reflects faunal mixing due to natural and anthropogenic disturbance, including introductions and invasion, precludes us from designating each of G6/G7, G8 and G10 into a different species. (C) 2017 Australian Society for Parasitology.Peer reviewe

Reappraisal of Hydatigera taeniaeformis (Batsch, 1786) (Cestoda: Taeniidae) sensu lato with description of Hydatigera kamiyai n. sp.

The common cat tapeworm Hydatigera taeniaeformis is a complex of three morphologically cryptic entities, which can be differentiated genetically. To clarify the biogeography and the host spectrum of the cryptic lineages, 150 specimens of H. taeniaeformis in various definitive and intermediate hosts from Eurasia, Africa and Australia were identified with DNA barcoding using partial mitochondrial cytochrome c oxidase subunit 1 gene sequences and compared with previously published data. Additional phylogenetic analyses of selected isolates were performed using nuclear DNA and mitochondrial genome sequences. Based on molecular data and morphological analysis, Hydatigera kamiyai n. sp. Iwaki is proposed for a cryptic lineage, which is predominantly northern Eurasian and uses mainly arvicoline rodents (voles) and mice of the genus Apodemus as intermediate hosts. Hydatigera taeniaeformis sensu stricto (s.s.) is restricted to murine rodents (rats and mice) as intermediate hosts. It probably originates from Asia but has spread worldwide. Despite remarkable genetic divergence between H. taeniaeformis s.s. and H. kamiyai, interspecific morphological differences are evident only in dimensions of rostellar hooks. The third cryptic lineage is closely related to H. kamiyai, but its taxonomic status remains unresolved due to limited morphological, molecular, biogeographical and ecological data. This Hydatigera sp. is confined to the Mediterranean and its intermediate hosts are unknown. Further studies are needed to classify Hydatigera sp. either as a distinct species or a variant of H. kamiyai. According to previously published limited data, all three entities occur in the Americas, probably due to human-mediated introductions

History of Taenia saginata Tapeworms in Northern Russia

Taenia saginata is the most common species of tapeworm infecting humans. Infection is acquired by eating cysticercus larvae in undercooked beef. A closely related species, T. asiatica, is found in eastern and southeastern Asia. The larvae of T. asiatica develop in viscera of pigs. In northern Russia, there is a third member of this morphologically indistinguishable group. Cysticerci of so-called northern T. saginata are found in cerebral meninges of reindeer, and the unique life cycle is dependent on a native custom of eating raw reindeer brain. We report the winding history of this mysterious tapeworm from the first reports to the present time. In addition, we confirm the position of this parasite as a strain of T. saginata by analyzing a mitochondrial DNA sequence of an archival specimen. The origin of this strain might date back to reindeer domestication and contacts between cattle-herding and reindeer-herding peoples in Asia

Molecular Characterization of Ctenotaenia marmotae (Frölich, 1802) Railliet, 1893 (Cyclophyllidea: Anoplocephalidae) Parasitizing Rodents of the Genus Marmota and Spermophilus from Eurasia

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

Distribution and Molecular Diversity of Paranoplocephala kalelai (Tenora, Haukisalmi & Henttonen, 1985) Tenora, Murai & Vaucher, 1986 in Voles (Rodentia: Myodes) in Eurasia

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

Distribution and molecular diversity of Paranoplocephala kalelai (Tenora, Haukisalmi & Henttonen, 1985) Tenora, Murai & Vaucher, 1986 in voles (Rodentia: Myodes) in Eurasia

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

Molecular characterization of Ctenotaenia marmotae (Frölich, 1802) Railliet, 1893 (Cyclophyllidea: Anoplocephalidae) parasitizing rodents of the genus Marmota and Spermophilus from Eurasia

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

Dog survey in Russian veterinary hospitals: tick identification and molecular detection of tick-borne pathogens

Abstract Background 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. Methods 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. Results 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. Conclusions 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