[DNA detection of pathogens transmitted by Ixodid ticks in blood of small mammals inhabiting the forest biotopes in Middle Irtysh Area (Omsk Region, West Siberia)].

Microtine rodents were captured in two disconnected sampling sites in Omsk region where Ixodes pesulrcatus and Ixodes trianguliceps are sympatric. In blood samples of rodents the DNA was revealed belonging to several ixodid-transmitted pathogens: Borrelia burgdorferi sensu lato (prevalence 20.0 and 6.0%, here and further values are given for the first and second site, respectively), Borrelia miyamotoi (8.3 and 2.0%), Anlaplasnma phagocytophilum (33.3 and 48.0%), Ehrlichia muris (30.0 and 2.0%) and Babesia microti (33.3 and 42.0%). Three genetic groups of A. phagocytophilhm based on 16S rRNA gene and groESL operon, as well as two genetic groups of B. microti, B. microti 'US'-type and B. microti 'Munich'-type, were detected.

[Genetic variation and differentiation of wood mice from the genus Sylvaemus inferred from sequencing of the cytochrome oxidase subunit 1 gene fragment].

To ascertain intra- and interspecific differentiation patterns of some Sylvaemus wood mice species (S. uralensis, S. sylvaticus, S. ponticus, S. flavicollis, and S. fulvipectus), sequence variation of the mitochondrial cytochrome oxidase subunit I gene (COI) fragment (654 bp) was analyzed and the data obtained using several molecular genetic markers were compared. Distinct isolation of all Sylvaemus species (including closely related allopatric S. flavicollis and S. ponticus), as well as of the European and Asian races of pygmy wood mouse S. uralensis at the COI gene was demonstrated. However, genetic differences of the Sylvaemus species were 1.5 times and more higher than the distance (D) between the races of S. uralenciis. This finding provides no ample grounds to treat the latter as the independent species. The only specimen of Pamir-Alay subspecies S. uralensis pallipes examined showed closest relatedness to to the Asian race, although was rather distant from it (D = 0.038). No reliable isolation of the eastern European and southern European chromosomal forms, representing the European race of S. uralensis, as well as of their presumptive hybrids from the outskirts of the city of Sal'sk, Rostov region, at the COI gene was revealed. A hybrid origin of the populations of pygmy wood mouse from the outskirts of the Talapker railway station, Novovarshavsky district, Omsk region, was confirmed. In preliminary studies, based on karyotypic characters, these populations were diagnosed as distant hybrids of the eastern European chromosomal form and the Asian race. In yellow-necked wood mouse S. flavicollis from the territory of Russia and Ukraine, weak differentiation into northern and southern lineages (with mean genetic distance between them of 0.020) was observed. Considerably different relative genetic distances between the races of S. uralensis and the S. flavicollis--S. ponticus species pair, inferred from the mitochondrial cytochrome oxidase and cytochrome b gene data, indicated that the rates of evolution of different mitochondrial genome regions could be very different. It is suggested that transformations of the cytochrome b gene, or at least its part, were irregular in time and/or in different phyletic lineages (i.e., accelerated upon the formation of pygmy wood mouse races, and delayed upon the establishment of S. flavicollis and S. ponticus).

[Changes in the ranges of pasture ixodid ticks of the genus Ixodes Latr., 1795 (Parasitiformes, Ixodinae) in Western Siberia].

The character of distribution of two species from the genus Ixodes, the Taiga tick Ixodes persulcatus and Ixodes pavlovskyi in the plain part of Western Siberia is analyzed. The northern border of the range of I. persulcatus in HMAO-Ugra was clarified on the basis of long-term data on the population density of adult and immature ticks (1960-2011). The shift of the southern border of the species range in Western Siberia at the background of anthropogenic transformation (forest restoring activity, stopped sanitary forest cutting, road construction etc) is demonstrated; peculiarities of the distribution of the Taiga tick in some localities of the southwestern Siberia is analyzed. The modern state of the tick population in the joint dwelling zone of I. persulcatus and I. pavlovskyi is characterized. Possible reasons of changes in the structure of tick communities toward total prevalence of I. pavlovskyi in recreation zones of Novosibirsk and Tomsk are discussed. It is noted that the most significant changes in the character of distribution of these two tick species in Western Siberia had evidently occurred after 1990. Just in this period, local stable populations of the Taiga tick to the south of its main range in Western Siberia (within Omsk and Novosibirsk Provinces) were formed; the character of its distribution in the right bank of the Ob River (Novosibirsk Province) and in the valley of the Tom River (Tomsk Province) had changed; I. pavlovskyi became the dominating species.

[Zonal types of host-parasite complexes of arthropods and small mammals in a flat part of Western Siberia].

Within a flat part of Western Siberia distribution of the small mammals and parasitic arthropods connected with them is accompanied by formation zonal host-parasite complexes dated for corresponding landscape zones or subzones: tundra complex dated for a tundra zone; forest complex dated for a forest zone (including subzones northern taiga, middle taiga, southern taiga and subtaiga); forest-steppe complex dated for a northern forest-steppe subzone; steppe complex dated for a southern forest-steppe subzone and steppe. Parasitic specificity of each type of a complex is defined by arthropods of different systematical and ecological groups: a tundra complex is defined by epizoite gamasid mites (Mesostigmata), forest and forest-steppe complexes is defined by tick (Ixodides) and fleas (Siphonaptera), steppe complex is defined by fleas and nidicolous gamasid mites.

[Characteristics of zonal distribution of the gamasid mites connected with small mammals and their nests in Western Siberia].

Analysis of long-term data on the fauna, landscape distribution, and structure of communities of the gamasid mites (Acari:Parasitiformes:Mesostigmata) connected with small mammals and their nests in the plain part of Western Siberia is carried out. By now, presence of 249 gamasid mite species is established in the territory under study, including 193 free-living and 56 parasitic species. Gamasid mites are represented by the maximal number of species on small mammals and in thers nests in northern forest-steppe (102 and 105 species respectively). Nine parasitic species from two ecological groups (epizoic and nidicolous) were found in all landscape zones of the West Siberian Plain, namely: 1) epizoic species Laelaps clethrionomydis Lange, 1955, Laelaps hilaris C. L. Koch, 1836, and Hyperlaelaps arvalis Zachvatkin, 1948 (obligatory non-exclusive hematophagous); 2) nidicolous species Androlaelaps casalis Berlese, 1887 (obligatory non-exclusive hematophagous), Eulaelaps stabularis C. L. Koch, 1836, Haemogamasus nidiformnes Bregetova, 1955 (facultative hematophagous), Haemnogamnasus ambulans Thorell, 1872 (obligatory non-exclusive hematophagous), Hirstionyssus isabellinus Oudemans, 1913, and Hirstionyssus eusoricis Bregetova, 1956 (obligatory exclusive hematophagous). Last three species demonstrate the mixed type of parasitism. The population of gamasid mites on small mammals is most specific in tundra, southern forest-steppe and steppe; the fauna of gamasid mites in nests is most specific in southern forest-steppe and steppe.

[Combined experimental infection of Microtus gregalis by tick-borne encephalitis and rabies viruses and probable interference]. / Sochetannaia éksperimental'naia infektsiia uzkocherepnykh polevok (Microtus gregalis) virusami kleshchevogo éntsefalita i beshenstva s vozmozhnym proiavleniem interferentsii.

Narrow-skulled voles (Microtus gregalis) were inoculated with tick-borne encephalitis (TBE) and rabies (RV) viruses isolated in the steppe zone of West Siberia. TBE infection was asymptomatic and nonlethal in all voles. The virus was eliminated from the voles between days 14 and 60 postinoculation. Only 1 of 26 tested animals produced anti-TBE antibodies in titer 1:20. RV infection was acute and lethal. All sick animals contained RV in the brain, 42.1% in salivary glands, 5.3% in the lungs and kidneys. The voles which survived RV inoculation had no RV. The voles inoculated with RV after TBE were less sensitive and had a longer incubation period in comparison with the animals challenged with RV alone. The differences augmented from day 0 to day 14 after TBE inoculation and became statistically significant on day 14. Later, 21 day after challenge with TBE virus, the differences almost disappeared. The role of possible interference in the evolution of virus-host interaction of Lyssaviruses is discussed.

[Parasite fauna of the water vole (Arvicola terrestris) and its nests in the south of Western Siberia]. / Parazitofauna vodianoi polevki (Arvicola terrestris) i ee gnezd na iuge Zapadnoi Sibiri.

Fauna of parasitic and free-living arthropods associated the water vole Arvicola terestris and its nests in various landscape zones and subzones of the south of Western Siberia has been studied. Total abundance of gamasid mites and ticks (Gamasoidea, Ixodidae), fleas and nidicolous arthropods in nests is high, and the set of nidicolous and parasite species is quite diverse, but everywhere the parasite fauna is characterized by a small amount of species reaching a high abundance: Laelaps muris on the voles, Haemogamasus ambulans in nests, Ixodes apronophorus and Megpbotris walkeri both on the voles and nests. Parasitic arthropods living on the voles or in their nests are characterized by higher and stables indices of infection, while these parameters for free-living arthropods were variable. The list of mesostigmatic mites parasitizing the water vole and its nests in the south of Western Siberia (Adamovich, Krylov, 2001) has been considerably supplemented. In total, the fauna of parsitiform mites (Acari: Mesostigmata and Ixodiddes) and fleas (Siphonaptera) associated with the water vole in the south of Western Siberia is represented by 97 arthropod species of 19 families, including 74 species of mesostigmatic mites (Gamasoidea), 6 species of ticks (Ixodidae) and 17 species of fleas.

[Landscape aspects of host-parasite relationships between parasitic arthropods and the narrow-skulled vole Microtus gregalis (Rodentia) in Western Siberia]. / Landshaftnye aspekty parazito-khoziainnykh otnoshenii chlenistonogikh i uzkocherepnoi polevki Microtus gregalis (Rodentia) v Zapadnoi Sibiri.

Comparative zoogeographic analysis of outcomes accumulated in the course of long-term investigation the parasitic and free-living arthropods (Acarina: Parasitiformes; Insecta: Siphonaptera) associated with three subspecies of the narrow-skulled vole (Microtus gregalis gregalis, M. g. major, M. g. eversmanni) in various landscape zones and subzones in a flat part of Western Siberia, foothills of the Altai-Sayan mountain system and mountains of Southwest Altai. The obtained data, on the one hand, recover specific features of certain parasite communities that reflect ecological peculiarity of a host species living in conditions of concrete landscapes, on the other hand, a high degree of similarity between species set of some ectoparasitic and nidicolous arthropod groups from different subspecies of M. gregalis. The systematic list of ectoparasitic and nidicolous arthropods associated with M. gregalis and representing Gamasoidea mites, ticks and fleas is provided.

[Parasite-host relationship of flies and small mammals in the Omsk region]. / Parazito-khoziainnye sviazi blokh i melkikh mlekopitaiushchikh Omskoi oblasti.

A generalized analysis of data on a flea fauna, range of their hosts in various natural zones, and features of parasite-host relationships between fleas and small mammals obtained in the Omsk province during long term researches in 1963-1997 is given. 35 flea species are recorded. The most mass species both on animals and in their nest is Ctenophthalmus assimilis; the numerous species are Amalareus penicilliger, Megabothros rectangulatus, M. walkeri, Peromyscopsylla silvatica, Ctenophthalmus unciatus, Palaropsylla sorecis, Doratopsilla birulai, Neopsylla pleskei, Hystrichopsylla talpae; the usual species--Ceratopsyllus garei, M. calcarifer, M. turbidus, Frontopsylla elata, Amphipsylla sibirica, A. kuznetzowi, Peromyscopsylla dasycnema, Radinopsylla integella, Catalagia dacenkoi. Other species are less numerous or infrequent. The general infection rate of the flea populations on rodents and insectivores makes 30.4%. For certain species it reaches 65.1% (on red-backed vole Cletrionomys rutilus), for regular groups--86.9% (on shrews of the genus Sorex). The greatest variety of the flea populations is observed on Microtus arvalis, the least one--on Sorex caecutiens and S. daphaenodon. In the nests of small mammals the variety of fleas is significantly lower. Based on the index of flea species relative "loyalty" to small mammals and their nest we have recognized 6 groups of fleas.

[Ecological and epizootic characteristics of various zonal types of natural reservoirs of alveococcosis in the Omsk region]. / Ekologo-épizootologicheskaia kharakteristika razlichnykh zonal'nykh tipov prirodnykh ochagov al'veokokkoza v Omskoi oblasti.

Natural foci of alveococcis of various zonal types were found in the Omsk region. The final pathogen hosts are red (aspen and birch forests, northern and southern forest-steppe, steppe) and corsac (southern forest-steppe and steppe) foxes and, perhaps, wolves (southern taiga). There are intermediate hosts, that are small mammals of 10 species, among which Clethrionomys voles (northern redbacked, large-toothed redbacked, and bank voles in the southern taiga; northern redbacked voles in the aspen and birch forests and northern forest-steppe), root ones (in the northern and southern forest-steppe, and steppe), narrow-skulled ones and house mice (in the southern forest-steppe and steppe) are of the greatest epizootological significance. The seasonal and biotopical dynamics of the spatial pattern of a natural alveococcis foci was established in the subareas of the south taiga and northern forest-steppe.

[The spread of hantaviruses in western Siberia]. / O rasprostranenii khantavirusov v Zapadnoi Sibiri.

Studies made in west Siberia established the existence of at least 4 hantavirus types: Puumala, Tula, Topografov, and Dobrava/Belgrade. The authors detected Puumala virus genovariants in voles, Tula virus in sagebrush and narrow-skulled voles, and Topografov virus in Siberian lemmings. The etiological role of the hantavirus Dobrada/Belgrade was defined in the structure of morbidity of hemorrhagic fever with the renal syndrome. In Russia, hantaviruses were first detected in mites: a hantavirus antigen was found in one of the enzyme immunoassayed pools of the mole mites (Haemogamasus ambulans) collected from the Siberian lemming brooding burrow in the near-floodplain habitats of the transitional Yenisei tundras in southwest Taimyr.