[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).

[Coordination of the changes in some sites of the hantaviral segments].

Correlation in the changes of the nucleotide and amino acid sequences at the Hantaan virus occurring in different parts of S- and M-segments were studied. The correlation was analyzed using comparison of substitutions in aligned nucleic sequences of the segments. Correlations of the nucleotide substitutions between S- and M-segments were observed. Probably, this coordination of the changes in both segments reflects features of the tertiary structure of RNA.

[Feather mite fauna (Astigmata) of birds of some passerine families (Passeriformes) in the south of Western Siberia].

Feather mites (Astigmata) are specialized parasites living on the plumage and skin of birds. The paper presents the data on the infestation of some passerines (Passeriformes) by feather mites in the south of the Western Siberia (Omsk and Tyumen Provinces). On 16 bird species, we found 24 species of feather mites, belonging to the families Analgidae, Dermoglyphidae, Pteronyssidae, Trouessartiidae and Proctophyllodidae. Among them, 19 species are common parasites of passerine birds examined; five species were detected on atypical hosts. Ten mite species were recorded for the first time on examined passerine species. The analysis of the distribution of abundant and ordinary mite species on their hosts demonstrated that the majority of bird species possesses specific distribution pattern on host plumage with the preference of certain feather types. We also obtained new data on host associations of several mite species.

[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.

[The application of polymerase chain reaction in real-time operation mode to detect DNA of agents of human granulocytic anaplasmosis and monocytic erlychiosis].

The analysis was applied to detect DNA of agents of human granulocytic anaplasmosis and monocytic erlychiosis. The sampling included 109 ticks of Ixodes species from Novosibirsk oblast and Khabarovsk kray and blood samples of 111 mouse-like rodents from Omsk oblast. The used techniques included polymerase chain reaction in real-time operation mode with set of reagents "RealBest DNA Anaplasma phagocytophilum/Ehrlichia muris, ehrlichia chaffeensis" ("Vector-Best" Novosibirsk) and double round polymerase chain reaction. The DNA of A. phagocytophilum, agent of granulocytic anaplasmosis and/or DNA of E. muris, agent of monocytic erlychiosis was detected in 21 ticks and in blood samples of 52 voles. Both techniques were applied. The DNA of A. phagocytophilum was detected in samples of 2 voles and in 1 tick only after polymerase chain reaction in real-time operation mode was applied. It demonstrated that the set of reagents "RealBest DNA Anaplasma phagocytophilum/Ehrlichia muris, ehrlichia chaffeensis" permits to detect the DNA of isolates of A. phagocytophilum subsumed to different genetic groups. The set can be used for fast and effective detection of the DNA of agents of agents of human granulocytic anaplasmosis and monocytic erlychiosis in suspensions of analyzed ticks and blood samples.

[Related substitutions in the small segment of Old World hantavirus genome].

Whether there were related nucleotide substitutions in the S-segments of the genome of Tula, Puumala, Hantaan, Dorava/Belgrad, and Seoul viruses was studied. The significance of the correlations found in nucleotide substitutions was estimated by the level of mutual information. The majority of the correlated changes were synonymous substitutions. The correlations were mostly restricted to non-synonymous substitutions sites: Tula 258 (a.a.) and Dobrava/Belgrad (56 a.a.). In the genome of Puumala, both synonymous (204, 215, and 254 a.a.) and non-synonymous (304 a.a.) changes occurred. For Hantaan virus, the related correlations were less frequent. For Seoul virus, such correlations were not revealed. Hence, for some viruses, the selection of mutation proceeded as related at several positions in a segment. The evolution of virus sequences may depend on the number of available correlations of nucleotide substitutions in the segment.

[Study of the phylogenetic relations of Puumala hantaviruses, by using the mutual information calculating method].

Phylogenetic relations were investigated in the group of Puumala viruses (the genus Hantavirus, the family Bunyaviridae) by the mutual information showing the similarity of the nucleotide sequences of S- and M-genome segments. There was evidence that recombination events might occurr in some Eurasian Puumala viruses (Scandinavian and West-Siberian genotypes). The investigation revealed the conservative sites available in the S and M segments that were common to most Puumala viruses, as well as the preservation of alternation and mutual arrangement of these sites in the S and M segments even for greatly diverging genotypes, which may be used in the detection of recombination events in Puumala viruses during further studies.

[Study of phylogenetic relations of hantaviruses by using the mutual information method. Tula genotype viruses].

Phylogenetic relations were studied in the group of Tula viruses (Hantavirus genus, Bunyaviridae family) of Eurasia. The similarity in the nucleotide sequences of segments was estimated by the value of mutual information. The application of this method confirmed that recombinant events might occur in some Tula-like viruses of Eurasia, as previously presumed by the results of bootscanning and analysis of amino acid sequences. It was found that might be recombination between distinct phylogenetic Tula sublineages; concepts of the microevolution of the group as a whole are specified.

[A study of possible transovarial and transphase transmission of borreliae by the tick Dermacentor reticulatus (Ixodidae)].

A study of possible transovarial and transphase transmission of borreliae by the tick Dermacentor reticulatus is carried out. The possibility of borreliae transmission by the ticks of this species being infected spontaneously as well as experimentally is shown in principle. Although borreliae are preserved in the organism of D. reticulatus, low values of the infestation are established in the different stages of D. reticulatus development and in all steps of the study. D. reticulatus may be involved in the process of borreliae circulation in natural foci of tick-born borreliosis, but this species has no a significant importance for the maintenance of it.

[The typing of tick-borne encephalitis virus strains by the soluble antigen]. / Tipirovanie shtammov virusa kleshchevogo éntsefalita po rastvorimomu antigenu.

Sucrose-acetone-treated antigens (SAA) and soluble antigens (SA) prepared from them by treatment with 8 M urea for eight TBE virus strains isolated in different parts of the virus distribution area were studied in cross CFT with immune ascitic fluids (IAF) for these strains as well as for OHF and Powassan viruses. With SAA, the difference in titres with homologous and heterologous IAFs, as a rule, did not exceed twofold, whereas with SA was 32-fold. It was also noted that in the homologous system the titre of SA decreased not more than 4-fold as compared with that of the initial SAA while in the heterologous system it declined from 4- to 16-fold or more. The level of antigenic relationship of strains was expressed by the formula HAg = SA titre/SA titre X 100%. It was shown that at HAg greater than or equal to 25% the strains used for antigen and antibody generation were closely related and at HAg less than or equal to 6.25% belonged to different subtypes. The analysis of the data suggested the existence of a fourth, "Urals-Siberian" antigenic variant of TBE virus. Using the developed criteria, the 20 strains under study (with one exception) were alloted into one of the four antigenic variants or qualified as intermediate.

[Influence of host-effect on strain variability of tick-borne encephalitis virus]. / K voprosu o vliianii host-éffekta na shtammovuiu izmenchivost' virusa kleshchevogo éntsefalita.

The organism of arthropods and warm-blooded vertebrates as a habitat of a virus determines the population genetic structure of tick-borne encephalitis (TBE) virus strains. The pattern of hybridization by variable zones of TBE genomes gradually changes in the course of intracerebral passages of the virus in newborn white mice. During intracelomal passages in Ixodidae hybridization alters as early as during the first passage, both for variable and (in individual cases) conservative zones. Ixodid ticks should be regarded as a mechanism maintaining the heterogeneity of virus communities (strains and populations). Vertebrates and communities of dugout arthropods appear to be the mechanism reducing the effect of ecologic isolation of TBE strains.

[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.

[Genomic changes in strains of the tick-borne encephalitis virus as a result of passages in mice]. / Izmenenie genomov shtammov virusa kleshchevogo éntsefalita v rezul'tate passazhei na myshakh.

Changes in genomes of TBE strains isolated from various sources at early stages of laboratory adaptation to white mice brain were demonstrated by molecular hybridization of nucleic acids with synthetic oligonucleotide probes, complementary RNA sites of reference TBE strains Sofyin and Neudorf. Of the 4 TBE strains passed 6 times through white mice brain in only 1 the level of RNA hybridization with 2 oligonucleotide probes was found changed, whereas in all the 3 tested strains the level of RNA hybridization with 1-2 oligonucleotide probes complementary to strain Sofyin was increased after 7-16 passages in the same system. The most noticeable changes in the genome were detected during readaptation to white mice of a TBE variant selected in passages on H. marginatum marginatum ticks.

[Genetic differentiation of hantaviruses using the polymerase chain reaction and sequencing]. / Geneticheskaia differentsiatsiia khantavirusov s pomoshch'iu polimeraznoi tsepnoi reaktsii i sekvenirovaniia.

Thirty-two hantavirus strains and 8 samples of lung tissue from rodents collected in different regions of Russia have been examined by molecular biological methods. Two methodological approaches have been employed for the study of genetic relationships between the viruses: nested PCR assay and common RT-PCR with subsequent direct sequencing of 200 and 365 base pair of G2 protein encoding regions of M-segment, respectively, and the resultant sequences were compared with those of the prototype hantavirus. The study revealed a mosaic pattern of distribution of different hantavirus genotypes on the territory of Russia.

[The characteristics of the relationships of arthropods of the refuge complex with the causative agents of transmissible viral infections in bird rookeries]. / Osobennosti sviazei chlenistonogikh ubezhishchnogo kompleksa s vozbuditeliami transmissivnykh virusnykh infektsii v kolonial'nykh poseleniiakh ptits.

The isolation of viruses of tick-borne encephalitis, West Nile fever, and Omsk hemorrhagic fever from arthropods of nests of colonial birds (rook, sand martin, tree sparrow, Laridae) in different zones of West Siberia (from tundra to steppe) has been analyzed. The role of gamasid mites, hematophages and saprophages, characteristic inhabitants of nests of colonial birds, and of the tick Ixodes lividus in connection with their biology, coadaptation with hosts, microclimatic nest conditions, etc. has been evaluated. It has been concluded that the whole nest community of arthropods in a nest rather than one infected individual has to be regarded as an infective unit in colonies.

[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.

[The Hydrachnidae water mites of southwestern Siberia in relation to their participation in arbovirus circulation]. / Vodianye kleshchi Hydrachnidae iuga Zapadnoi Sibiri v sviazi s ikh uchastiem v tsirkuliatsii arbovirusov.

The phenomenon of Hydrachnidae association with the tick-borne encephalitic viruses complex has been found out during the study of the role of the Hydrachnidae in the arboviruses circulation. We investigated the fauna, studied the quantity variation and trophic relations of these arthropods and blood-sucking Diptera. It was revealed no trophic relations between blood-sucking Diptera and mite species, where TBE strains were isolated from. On the basis of faunistic and virological study we suppose, that Hydroacarinae got an infection with the virus in the nymphal and imago stages, as well as larvae of mosquitos. Authors also note, that trophic relations between blood-sucking Diptera and chiggers (Trombidiidae) may be important in the arboviruses ecology.

[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.