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  • Author or Editor: Miklós Gyuranecz x
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Francisella tularensis is a Gram-negative bacterium, the causative agent of the zoonotic disease tularaemia. The bacterium has developed several extracellular and intracellular strategies to evade the hosts’ innate and adaptive immune responses. The aims of the study were to examine complement sensitivity of wild and attenuated F. tularensis ssp. holarctica strains in animal hosts of distinct sensitivity to the bacterium, to compare the complement-evading ability of wild strains of different phylogeographic background, and to examine the role of factor H in the host–pathogen interactions. Complement sensitivity assays were carried out on various F. tularensis ssp. holarctica wild strains and on the attenuated live vaccine strain (LVS) with sera of the highly sensitive house mouse (Mus musculus), the moderately sensitive European brown hare (Lepus europaeus) and the relatively resistant cattle (Bos taurus). Specific binding of complement regulator factor H to bacterial membrane proteins was examined by Western blot assays. All wild strains interacted with the hosts’ complement system and showed no significant differences in their survivability. The attenuated LVS was resistant to serum killing in mouse, but was lysed in the sera of hare and cattle. Direct binding of factor H to F. tularensis membrane proteins was not detected.

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Authors: László Fodor, Katalin Jánosi, László Makrai and Miklós Gyuranecz

A total of 860 serum samples collected at 86 cattle farms in different parts of Hungary were screened for the presence of antibodies to Mycoplasma bovis using an ELISA test with a recombinant M. bovis membrane protein as antigen. Antibodies to M. bovis were detected in sera collected on all farms, and no farms negative for M. bovis were found. In 88.38% of the herds more than 50% of the sampled animals were infected by M. bovis. A total of 82.91% of the animals had antibodies to M. bovis. The proportion of seropositive animals was higher in the older age groups, and a significant difference was seen in the level of seropositivity between young and older age groups. The results show that M. bovis infection is widespread on Hungarian dairy farms, and its prevalence has increased in the recent decade. The high infection rate of Hungarian cattle herds with M. bovis shows that special attention should be paid to evaluating the aetiological role of M. bovis in bovine respiratory disease complex (BRDC) cases because M. bovis has an immunosuppressive effect and can predispose cattle to other respiratory infections, too.

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Authors: Sándor Hornok, Maria Mulvihill, Krisztina Szőke, Enikő Gönczi, Kinga M. Sulyok, Miklós Gyuranecz and Regina Hofmann-Lehmann

Man-made barriers are well known for their effects on ecosystems. Habitat fragmentation, for instance, is a recognised consequence of modern-day infrastructure. The aim of the present study was to investigate the diversity and abundance of tick species, as well as the risks of acquiring tick-borne infections in habitats adjacent to a freeway. Therefore, ixodid ticks were collected from the vegetation at two-week intervals (in the main tick season, from March to June) in eight habitats of different types (forest, grove, grassland) along both sides of a freeway. Ixodes ricinus females were molecularly screened for three species of tick-borne bacteria. In the study period, 887 ixodid ticks were collected. These included 704 I. ricinus (79.4%), 51 Dermacentor reticulatus (5.7%), 78 D. marginatus (8.8%), 35 Haemaphysalis inermis (3.9%) and 19 H. concinna (2.1%). There was no significant difference in the abundance of tick species between similar habitats separated by the freeway, except for the absence of Dermacentor spp. on one side. In I. ricinus females, the overall prevalence of Anaplasma phagocytophilum was low, and (in part due to this low rate) did not show significant difference between the two sides of the freeway. Rickettsia helvetica had significantly different overall prevalence between two distant habitats along the same side of the freeway (12.3% vs. 31.4%), but not between habitats on the opposite sides. Borrelia burgdorferi s.l. showed significantly different overall prevalence between habitats both on the same and on the opposite sides of the freeway (8.6–35.9%), and the difference was higher if relevant habitats were also separated by the freeway. Importantly, the prevalence rate of the Lyme disease agent was highest in a forested resting area of the freeway, and was significantly inversely proportional to the prevalence of A. phagocytophilum (taking into account all evaluated habitats), apparently related to deer population density. Prevalence rates of these bacteria also differed significantly on single sampling occasions between: (1) closely situated habitats of different types; (2) distant and either similar or different habitat types; and (3) habitats on the opposite sides of the freeway. In conclusion, the findings of the present study show that a fenced freeway may contribute to differences in tick species diversity and tick-borne pathogen prevalence along its two sides, and this effect is most likely a consequence of its barrier role preventing deer movements.

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Authors: Katalin Jánosi, László Stipkovits, Róbert Glávits, Tamás Molnár, László Makrai, Miklós Gyuranecz, János Varga and László Fodor

The purpose of this study was to develop and evaluate an aerosol infection method with Histophilus somni that closely resembles the natural way of infection of calves. Another aim was to compare the virulence of two H. somni strains by collecting clinical and postmortem data of experimentally infected and control animals. Seventeen conventionally reared 3-month-old calves were divided into three groups. Two groups of six animals each were exposed to suspensions containing H. somni on three consecutive days using a vaporiser mask. The third group of five animals was used as control. The data of individual clinical examination were recorded daily. All animals were exterminated, and gross pathology of all lungs was evaluated on the 15th day after the first infection. Both H. somni strains caused an increase of rectal temperature, respiratory signs, decrease of weight gain, and severe catarrhal bronchopneumonia in both infected groups. Although some chronic lesions were detected in the lungs of the control animals as well, the histopathological findings in the infected and control groups were different. H. somni was recultured from all lungs in the challenged groups but it could not be reisolated or detected by PCR examination in the control group. This is the first paper on aerosol challenge of calves with H. somni using repeated infection and verified by detailed pathological, bacteriological and histopathological examination. The infection method proved to be successful. There was no difference in the virulence of the two H. somni strains used in the trial.

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Authors: Zsuzsa Kreizinger, Kinga Mária Sulyok, László Makrai, Zsuzsanna Rónai, László Fodor, Szilárd Jánosi and Miklós Gyuranecz

The susceptibility of 29 Bacillus anthracis strains, collected in Hungary between 1933 and 2014, was tested to 10 antibiotics with commercially available minimum inhibitory concentration (MIC) test strips. All strains were susceptible to amoxicillin, ciprofloxacin, clindamycin, doxycycline, gentamicin, penicillin, rifampicin, and vancomycin. Intermediate susceptibility to erythromycin and cefotaxime was detected in 17.2% (5/29) and 58.6% (17/29) of the strains, respectively. Correlations were not observed between the isolation date, location, host species, genotype, and antibiotic susceptibility profile of strains.

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Babesia vesperuginis is the only piroplasm known to infect bats. Unlike most members of the genus Babesia, it is probably transmitted by a soft tick species (i.e. Argas vespertilionis). Recently, two studies have been conducted to clarify the phylogenetic status of this species, and both agreed on placing it into a basal position among Babesia sensu stricto (s.s.). However, several important groups of piroplasms were not included in the already reported phylogenetic trees of B. vesperuginis isolates. Therefore, the aim of the present study was to amplify an approx. 950-bp fragment of the cytochrome c oxidase subunit 1 (cox1) gene of B. vesperuginis from A. vespertilionis specimens, and to compare its sequences with those from other piroplasmid groups in a broader phylogenetic context. Sequence comparisons focusing on either 18S rRNA or cox1 genes, as well as phylogenetic analyses involving separate and concatenated 18S rRNA and cox1 sequences indicate that B. vesperuginis is more closely related to the phylogenetic group of Theileriidae than to Babesia s.s. In particular, B. vesperuginis clustered closest to Cytauxzoon felis and the ‘prototheilerid’ B. conradae. The results of this study highlight that B. vesperuginis is a unique and taxonomically important species, which should be included in future studies aimed at resolving the comprehensive phylogeny of Piroplasmida.

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Authors: Sándor Hornok, Getachew Abichu, Nóra Takács, Miklós Gyuranecz, Róbert Farkas, Isabel G. Fernández De Mera and José De La Fuente

Hard ticks and tsetse flies are regarded as the most important vectors of disease agents in Sub-Saharan Africa. With the aim of screening these blood-sucking arthropods for vector-borne pathogens belonging to the family Anaplasmataceae in South-Western Ethiopia, four species of tsetse flies (collected by traps) and seven species of ixodid ticks (removed from cattle) were molecularly analysed. DNA was extracted from 296 individual ticks and from 162 individuals or pools of tsetse flies. Besides known vector–pathogen associations, in Amblyomma cohaerens ticks sequences of Anaplasma marginale and A. phagocytophilum were detected, the latter for the first time in any ticks from cattle in Africa. In addition, part of the gltA gene of Ehrlichia ruminantium was successfully amplified from tsetse flies (Glossina pallidipes). First-time identification of sequences of the above pathogens in certain tick or tsetse fly species may serve as the basis of further epidemiological and transmission studies.

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