Győző Horváth

Comparison of red fox Vulpes vulpes and pine marten Martes martes food habits in a deciduous forest in Hungary

Abstract Feeding habits and interspecific trophic niche overlap of two sympatric predators, the pine marten Martes martes and the red fox Vulpes vulpes, were studied in a deciduous forest habitat in Hungary with conditions of differing abundance and dominance in the rodent community. The main food source of the predators consisted of small mammals, mainly rodents. Consumption of small mammals was higher during bank vole Clethrionomys glareolus dominated years than in Apodemus mice dominated years. Both predators preferred bank voles as prey and consumed less Apodemus mice and shrews (Soricidae) than expected by availability. The two opportunistic predators utilised different, seasonally-dependent food resources. Martens consumed more plants, reptiles, amphibians and fish, whereas foxes consumed more small mammals and ungulate carcasses. In summer and autumn, percent biomass of bank voles in marten diet and Apodemus mice in fox diet was positively correlated with the number of rodents in the available food resources. In winter and spring, the density of rodents varied slightly; therefore, variations in the diets of these two predators were not related to prey density. The prey consumed was characteristically terrestrial and small sized (< 50 g). There was no difference in prey weight distribution between martens and foxes, but martens consumed more arboreal and foxes more terrestrial prey. The standardised food niche breadth did not differ significantly between the two species. Food niche overlap between the two predators was higher in winter and spring, but the difference between seasons was not significant (mean overlap  =  72%). In comparison with higher latitudes, we found a larger food niche overlap in our study.

First detection of Tula hantaviruses in Microtus arvalis voles in Hungary

Tula hantavirus (TULV) is a member of the genus Hantavirus, family Bunyaviridae and is mainly carried by the European common vole (Microtus arvalis). In order to detect TULV, we tested Microtus arvalis (MAR) and Microtus subterraneus (MSU) voles captured in two different locations of the Southern Transdanubian region of Hungary. The viral genome was detectable in 37% of the tested MAR voles but, interestingly, was absent in all MSU. Phylogenetic analysis performed with a partial coding sequence of the capsid gene showed that Hungarian TULV strains clustered with viruses detected in western Slovakia and in the Czech Republic. To the best of our knowledge, this is the first report on the identification of TULV detected in MAR voles in the Transdanubian region of Hungary.

Detection of Dobrava-Belgrade hantavirus using recombinant-nucleocapsid-based enzyme-linked immunosorbent assay and SYBR Green-based real-time reverse transcriptase-polymerase chain reaction

Dobrava (DOBV) hantaviruses belong to the genus Hantavirus, family Bunyaviridae, and are carried by yellow-necked and striped field mice. The goal of this study was to detect DOBV using serological and genetic methods in Apodemus rodents in Hungary and in northern Croatia. During the study period, a total of 125 Apodemus sp. (67 A. agrarius, 58 A. flavicollis) were tested for the presence of hantaviruses, and 21 rodents (17%) were positive by rRT-PCR and/or ELISA. We conclude that the prevalence of DOBV is much higher than previously anticipated. The simultaneous use of molecular and serological techniques provides a highly reliable way to detect hantavirus infections.

Molecular characterization of Dobrava and Kurkino genotypes of Dobrava-Belgrade hantavirus detected in Hungary and Northern Croatia

Among the Hantavirus genus, Saaremaa virus (SAAV) has been the subject of taxonomical debates. While the International Committee on Taxonomy of Viruses declares SAAV as a distinct species, several European hantavirus experts proposed that SAAV is in fact a genotype of Dobrava-Belgrade virus (DOBV). In the present study we performed S-segment-based phylogenetic analysis of eight DOBV strains identified in rodents in Hungary and Northern Croatia. These new sequences considerably increase the number of complete nucleoprotein gene sequences deposited in the NCBI database. Our phylogenetic analysis clearly support the taxonomical nomenclature recently proposed for DOBV, i.e., genotypes such as Dobrava, Saaremaa, Kurkino, and Sochi should indeed be classified within the DOBV hantavirus species. Moreover, we found that only the Dobrava and Kurkino genotypes of DOBV species are circulating in Hungary while currently there is no evidence for the presence of Saaremaa genotype.

Isolation and complete genome characterization of novel reassortant orthoreovirus from common vole (Microtus arvalis)

A novel mammalian orthoreovirus (MRV) strain was isolated from the lung tissue of a common vole (Microtus arvalis) with Tula hantavirus infection. Seven segments (L1–L3, M2–M3, S2, and S4) of the Hungarian MRV isolate MORV/47Ma/06 revealed a high similarity with an MRV strain detected in bank vole (Myodes glareolus) in Germany. The M1 and S3 segment of the Hungarian isolate showed the closest relationship with the sequence of a Slovenian human and a French murine isolate, respectively. The highest nucleotide and amino acid identity values were above 90 and 95% in all of the comparisons to the reference sequences in GenBank, except for the S1 with a maximum of 69.6% nucleotide and 75.4% amino acid identity. As wild rodents are among the main sources of zoonotic infections, the reservoir role of these animals and zoonotic potential of rodent origin MRVs need to be further investigated.

Serosurvey of pathogenic hantaviruses among forestry workers in Hungary.

ObjectivesThe aim of the study was to survey the prevalence of human hantavirus infections among forestry workers, who are considered a risk population for contracting the disease. Sera collected from volunteers were tested for antibodies against Dobrava-Belgrade (DOBV) and Puumala (PUUV) viruses.Material and MethodsFor serological analyses, full capsid proteins of DOBV and PUUV viruses were produced in a bacterial expression system, while Ni-resin was used for protein purification. Samples were screened for anti-hantavirus antibodies by ELISA, results were confirmed by Western blot analysis.ResultsA total of 835 samples collected from 750 males and 85 females were tested by indirect ELISA and positive test results were confirmed by Western blot assay. Out of the 45 ELISA-reactive samples, 38 were confirmed by Western blot analysis. The regional distribution of seropositive individuals was as follows: 1.9% (2/107) in the Danube-Tisza Plateau (Great Plains), 3.1% (10/321) in the Southern Transdanubian region, 5.2% (13/248) in the Northern Transdanubian, and 8.2% (13/159) in the North Hungarian Mountains.ConclusionsOur data show marked geographic differences in seroprevalence of pathogenic hantaviruses within Hungary, indicating elevated exposure to hantavirus infections in some areas.