Tamás Tuboly

University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca, Judetul Cluj, Romania

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Publications (33)62.43 Total impact

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    ABSTRACT: In recent years, the number of cases of disease caused by canine parvovirus 2 (CPV-2) in vaccinated dogs has increased. The aim of the present study was to identify CPV-2 strains present in Hungary. Forty-two out of 50 faecal specimens examined were positive, and 25 VP2 sequences were determined and analysed. Based on the current classification, the Hungarian viruses belong to New CPV-2a type, except two viruses that are recombinants of vaccine viruses and CPV-2a strains. The Tyr324Ile alteration was detected for the first time in Europe, and a "Hungarian-specific" substitution (Ala516Thr) was also identified in this study. The immunologically important parts of the currently spreading canine parvoviruses were examined and found to differ greatly from the vaccine strains that are widely used in Hungary.
    Archives of Virology 04/2014; · 2.03 Impact Factor
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    ABSTRACT: Porcine circovirus type 2 (PCV2) causes some of the most significant economic losses in pig production. Several multisystemic syndromes have been attributed to PCV2 infection, which are known as PCV2-associated diseases (PCVDs). This study investigated the origin and evolution of PCV2 sequences in domestic pigs and wild boars affected by PCVDs in Croatia. Viral sequences were recovered from three wild boars diagnosed with PCV2-systemic disease (PCV2-SD), 63 fetuses positive for PCV2 DNA as determined by PCR, 14 domestic pigs affected with PCV2-SD (displaying severe interstitial nephritis) and five domestic pigs with proliferative and necrotising pneumonia. Seventeen complete PCV2 genomes were recovered. Phylogenetic and evolutionary analyses based on median-joining phylogenetic networks, amino acid alignments and principal coordinate analysis were performed using complete genomes, as well as complete and partial ORF sequences for ORF1 and ORF2. Two of the 17 PCV2 sequences belonged to PCV2a, 14 to PCV2b and one was unclustered. PCV2b was the predominant genotype in Croatia and has been linked to international trade as a route of introduction. Correlation between particular viral strains with PCVDs is lacking.
    The Veterinary record 03/2014; · 1.80 Impact Factor
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    ABSTRACT: To elucidate the spatio-temporal phylodynamics, dispersion and evolutionary processes underlying the emergence of novel porcine parvovirus 2-4 species, we analyzed all available complete capsid genes together with ours obtained in Europe. Bayesian phylogeography indicate that Romania (PPV2 and PPV4) and Croatia (PPV3) are the most likely ancestral areas from which PPVs have subsequently spread to other European countries and regions. Our time-scaled reconstruction supported a relatively recent history of the currently circulating novel PPV species (1920s - 1980s) in the domestic or sylvatic host. While PPV2 strains exhibit a large genetic exchange characterized by significant recombination and gene flow between distinct regions and hosts, PPV3 and PPV4 showed a diversification reflected by the accumulation of geographically structured polymorphisms. The RNA-like evolutionary rates detected, inter- and intra-host recombination and the positive selection sites provide evidence that the PPV2-4 capsid gene plays a prominent role in host adaptation.
    Journal of General Virology 07/2013; · 3.13 Impact Factor
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    ABSTRACT: Transmissible gastroenteritis (TGE) is a coronavirus-induced disease of pigs, characterised by diarrhoea and vomiting. The incidence of the disease had been decreasing since the late 1980s when deletion mutant variants (porcine respiratory coronavirus, PRCoV) of the virus emerged, repressing TGE gradually. Although disease manifestations are infrequent, the virus is still present in pig herds, causing sporadic outbreaks in a milder form. Identification and characterisation of the spike genes from TGEV and PRCoV, detected in such outbreaks, were performed in Hungary. Analysis of the amplified partial gene sequences showed that TGEV was present in herds with TGE clinical signs together with PRCoV. The sequences, apart from the deletions in PRCoV, were identical and at least two types of PRCoV spike proteins could be identified based on the length of the deleted sequence.
    Acta Veterinaria Hungarica 07/2013; · 1.17 Impact Factor
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    ABSTRACT: A recombinant cucumber mosaic virus based expression system has been developed for the production of an immunogenic porcine circovirus epitope. The resulting nanoparticle was shown to elicit specific immune response in mice and pigs, when administered parenterally. To evaluate the oral applicability of this vaccine candidate, two experiments were performed. In the first one, the resistance of the vector itself to mucosal environment was tested in mice. Cucumber mosaic virus particles fed to mice were able to elicit specific mucosal and serum antibody production. In the second experiment, recombinant cucumber mosaic virus fed to piglets resulted in the appearance of porcine circovirus specific serum antibodies. The vector proved to be able to survive in the gastrointestinal tract, so that an epitope expressed on its surface could induce specific immune response. These results indicate that the developed plant virus based expression system offers an effective method for mucosal vaccine production.
    Acta Veterinaria Hungarica 07/2013; · 1.17 Impact Factor
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    ABSTRACT: Torque teno sus viruses (TTSuV1-2), members of the newly established family Anelloviridae are considered non-pathogenic emerging viral agents of Suidae species. However, the genetic diversity, phylogeny and evolutionary processes responsible for the emergence and spread of TTSuVs in wild boars remain poorly understood. Here we implemented phylogenetic and evolutionary analyses to address key questions on the genetic diversity, evolutionary scenario and spatio-temporal dynamics of emerging TTSuVs in wild boars of the Western region (Transylvania) of Romania. High levels of genetic diversity of wild boar origin TTSuV1-2 have been found as well as a new TTSuV1 genotype and several new subtypes. Phylogenies suggest that several wild boar viral strains in both TTSuV species are likely to have emerged from a well-defined ancestor approximately 40 (TTSuV1) and 18 (TTSuV2) years ago and showed independent evolutionary trajectories. Bayesian phylogeography showed an intense flow of viral strains throughout the Transylvanian counties possibly related to wild host migrations, facilitating the rapid spread of TTSuVs. The intra-genotype and inter- and intrahost level recombination, intense spatio-temporal viral flow and the positively selected sites found in the ORF2 genes should be considered important driving forces shaping TTSuVs evolution. The first reported rates of nucleotide substitution for porcine anelloviruses, estimated to be 5.29-5.51×10(-4)subs site(-1)year(-1), are in line with those measured previously for mammalian ssDNA viruses and RNA viruses. These high evolutionary rates of TTSuVs, independent of recombination, are reflections of adaptive evolution, an important factor in the emergence of novel viral variants which may explain their ability to emerge in Suidae hosts.
    Veterinary Microbiology 06/2013; · 3.13 Impact Factor
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    ABSTRACT: Recently a new group of circoviruses have been detected in tissues of Barbel fish and European catfish in Hungary. In our study circovirus genomes were screened in eight additional fish species for the detection and characterization of circoviruses. Two species of these bore circoviral sequences based on conventional PCR assay targeting the replication-associated protein coding gene fragments. Interestingly, the methods successfully used before failed to amplify other parts of the circular viral genome, suggesting the presence of partial, integrated genetic elements in the genome of the host. The successfully sequenced fragments of the Indian rohu (Labeo rohita) encoded mutations which may cause frameshifts or termination in the coding region described previously in other vertebrates. Phylogenetic analyses presumed that integration of the viral genetic elements might have progressed concurrently or following the diversification of cyprinid fish. Further studies on the nature of whole circovirus genomes and integrated elements may help to understand their potential role and evolution in different fish species.
    Virus Genes 06/2013; · 1.77 Impact Factor
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    ABSTRACT: Improvements and widespread use of nucleic acid amplification and sequencing methods have led to the recognition of new virus diversity in various domestic animals, including pigs. In this study we utilized either virus species specific or broadly reactive PCR assays to describe the occurrence and genetic diversity of selected DNA viruses belonging to families Adenoviridae, Circoviridae, Anelloviridae and Parvoviridae in Cameroonian pigs. Fecal specimens were collected during spring of 2011. No adenoviruses, circoviruses and anelloviruses were detected, however, high prevalence and remarkable genetic diversity within the identified parvoviruses and, particularly, within bocaviruses was observed. PPV4 was the most prevalent virus (20%), followed by PBoV3 (18%), PBoV4 (18%), PBoV5 plus 6V/7V (16%), and PBoV1 plus PBoV2 (6%). The frequency of mixed infections with various combinations of these virus species reached 20%. Genetic analysis of the identified viruses showed that the capsid gene of PBoV1 and PBoV2 strains shared up to 91% and 94% nt sequence similarities to reference PBoV1 and PBoV2 strains, respectively. The identified PBoV3 and PBoV4 strains shared ⩽95% and ⩽98% nt identities with reference PBoV3 and PBoV4 strains, respectively, along the NS gene, whereas the PBoV5 strains shared 86% nt identities with Hungarian and 87% nt identities with Chinese PBoV5 strains along the capsid gene. In addition, a single PBoV5-like strain shared ⩽ 71% nt sequence identity with other PBoV5 strains. This is the first study to report evidence of the circulation of bocaviruses in Africa and contributes to our understanding of the impact of globalization on the dispersal of new and emerging viruses.
    Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases 03/2013; · 3.22 Impact Factor
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    ABSTRACT: In addition to the well known "classical" porcine parvovirus (PPV1; responsible for reproductive failure of susceptible sows) several new porcine parvoviruses have been recognized (PPV2, PPV3 and PPV4) in recent years. The genetic variation, characteristics and evolutionary factors shaping these novel PPVs were studied by comparing the complete capsid (cap) genes of PPVs from domestic pigs and wild boars. Using Bayesian coalescent methods we estimated the rate of nucleotide substitution for PPV2, PPV3 and PPV4 to be of the order of 3.86×10(-4)-8.23×10(-4)subs site(-1)year(-1), similar to those commonly measured for RNA viruses, although this rate in case of PPV2 is probably influenced by frequent recombination events. Given such rapid evolutionary dynamics, it is likely that novel PPVs will continue to improve their capacity to spread among Suidae hosts worldwide. The mean time to the most recent common ancestor for the sampled genetic diversity of the newly discovered porcine parvoviruses was estimated. The results indicated that novel PPVs originated within approximately the last 70years. Incongruent phylogenetic relationships of several strains suggested recombination events supported by several recombination-detecting methods and by split-decomposition phylogenetic networks. Analyses of the selective constraints acting on each codon suggest that some regions of PPV cap genes were under positive selection. This study showed that inter- and intraspecies recombination and diversifying selection pressures are prevalent across the cap genes of novel PPVs, and beside host switching and gene flow are important driving forces of their evolution and may be significant factors in the emergence of new viral variants
    Molecular Phylogenetics and Evolution 01/2013; · 4.07 Impact Factor
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    ABSTRACT: In addition to the well known "classical" porcine parvovirus (PPV1; responsible for reproductive failure of susceptible sows) several new porcine parvoviruses have been recognized (PPV2, PPV3 and PPV4) in recent years. The genetic variation, characteristics and evolutionary factors shaping these novel PPVs were studied by comparing the complete capsid (cap) genes of PPVs from domestic pigs and wild boars. Using Bayesian coalescent methods we estimated the rate of nucleotide substitution for PPV2, PPV3 and PPV4 to be of the order of 3.86×10(-4)-8.23×10(-4)subs site(-1)year(-1), similar to those commonly measured for RNA viruses, although this rate in case of PPV2 is probably influenced by frequent recombination events. Given such rapid evolutionary dynamics, it is likely that novel PPVs will continue to improve their capacity to spread among Suidae hosts worldwide. The mean time to the most recent common ancestor for the sampled genetic diversity of the newly discovered porcine parvoviruses was estimated. The results indicated that novel PPVs originated within approximately the last 70years. Incongruent phylogenetic relationships of several strains suggested recombination events supported by several recombination-detecting methods and by split-decomposition phylogenetic networks. Analyses of the selective constraints acting on each codon suggest that some regions of PPV cap genes were under positive selection. This study showed that inter- and intraspecies recombination and diversifying selection pressures are prevalent across the cap genes of novel PPVs, and beside host switching and gene flow are important driving forces of their evolution and may be significant factors in the emergence of new viral variants
    Molecular Phylogenetics and Evolution 01/2013; · 4.07 Impact Factor
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    ABSTRACT: Porcine parvovirus (PPV) is widespread among swine and is responsible for reproductive failure of susceptible sows, characterized by embryonic and fetal death. Studies showed that PPV in domestic pig is genetically diverse and some strains differ from the ones used for vaccination. Organ samples from wild boars and domestic pigs were collected in Transylvania (Romania) and tested for the presence of PPV by polymerase chain reaction. Positive samples were grouped and 14 from the wild boar and 1 from the domestic pig PPVs were selected for VP1/VP2 sequence analysis and comparison with available GenBank data. The molecular clock analysis revealed that PPV has a relatively recent evolutionary history, originated approximately 120 years ago and the main divergence occurred in the last 20-60 years. Phylogenetic and residue substitution analysis showed that the viruses could be divided into 6 distinct clusters and that wild boar PPVs were partially different and independent from domestic pig PPVs. PPVs of wild boars proved to be more diverse than viruses of domestic pigs. The presence of the highly virulent 27a-like PPV strains in wild boars was also detected.
    Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases 04/2012; 12(6):1163-71. · 3.22 Impact Factor
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    ABSTRACT: Circular single-stranded DNA viral genomes had been identified worldwide in different species and in environmental samples. Among them, viruses belonging to the genus Circovirus of the family Circoviridae are present in birds and pigs, and recently, they were detected in barbels. The present study reports the identification of a new circovirus in fish. PCR amplification and sequencing were used to identify the novel circular DNA virus in European catfish (Silurus glanis). Full genome characterization and phylogenetic analysis showed that the virus belonged to the family Circoviridae and that it was distantly related to the previously described barbel circovirus.
    Archives of Virology 03/2012; 157(6):1173-6. · 2.03 Impact Factor
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    ABSTRACT: : Porcine circovirus type 2 (PCV2), the causative agent of a number of PCVAD (porcine circovirus associated diseases), is ubiquitous in domestic pig and wild boar populations. In the present study, using recombination detection program, phylogenetic analysis and base-by-base comparison of 28 PCV2 ORF2s (capsid protein coding gene) from wild boars and 8 from domestic pigs of Transylvania, recent natural intra- (PCV2b-1B/PCV2b-1C) and inter-genotype (PCV2a-2D/PCV2b-1C) recombination events were detected. Notably, one potential recombinant (F1-21) was detected in domestic pig with possible parental strains of wild boar origin. The estimated recombinant breakpoints comprised epitopes A, B and C of ORF2, without major changes in amino acid sequences. The prevalence of PCV2 in the wild boar population during the 5-year period following the first outbreaks of postweaning multisystemic wasting syndrome (PMWS) in domestic pigs in Romania showed a decrease from 13.4% to 8.3%. To our knowledge, this is the first study to show the existence of ORF2-based intra- and inter-genotype recombination in wild boar populations and the possible recombination between PCV2 strains of wild boars and domestic pigs. Our results suggest a certain independence of PCV2 infection in wild boar populations and demonstrate the possibility of infection with multiple PCV2 genotypes under natural circumstances. On the other hand, PCV2 genotypes specific for wild boars could be detected in domestic pig at lower frequency suggesting the possible spread of wild boar PCV2 to domestic swine. The recombination events described here may contribute to the genetic diversity of PCV2 and may also be the source of emergence of new PCV2 strains.
    International Journal of Molecular Epidemiology and Genetics 03/2012; 12(2):420-7..
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    ABSTRACT: A number of newly identified porcine parvoviruses had been described during the last decade, but the presence and prevalence of these viruses are unknown in Hungary and only partly known for Europe. The present study was conducted to detect and measure the prevalence of these viruses, namely porcine parvovirus (PPV) 2, PPV3, PPV4, porcine bocavirus (PBoV) 1, PBoV2, PBo-likeV and the 6V and 7V parvoviruses. The prevalence of PPV1 and porcine circovirus type 2 (PCV2) was also investigated. Faecal samples, blood serum samples, organ tissues, foetuses and semen were collected from different swine herds in Hungary and tested by polymerase chain reaction methods specific for the different viruses. The results indicated that all of the examined parvoviruses were present in Hungary, hence in Europe. The prevalence was 18.1% for PCV2, 0.5 % for PPV1, 6.4% for PPV2, 9.7% for PPV3, 6.4% for PPV4, 1.5% for PBo-likeV, 4.8% for PBoV1 and PBoV2 and 1.8% for 6V and 7V. Based on the analysis of partial PPV4 and PBo-likeV sequences, these viruses showed a high degree of sequence conservation, whereas PPV3 and the majority of PPV2, PBoV1, PBoV2, 6V and 7V sequences showed higher variability. Possible sites of recombination were also identified between PBoV1 and PBoV2 genomes.
    Archives of Virology 03/2012; 157(6):1003-10. · 2.03 Impact Factor
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    ABSTRACT: Porcine circovirus type 2 (PCV2), the causative agent of a number of PCVAD (porcine circovirus associated diseases), is ubiquitous in domestic pig and wild boar populations. In the present study, using recombination detection program, phylogenetic analysis and base-by-base comparison of 28 PCV2 ORF2s (capsid protein coding gene) from wild boars and 8 from domestic pigs of Transylvania, recent natural intra- (PCV2b-1B/PCV2b-1C) and inter-genotype (PCV2a-2D/PCV2b-1C) recombination events were detected. Notably, one potential recombinant (F1-21) was detected in domestic pig with possible parental strains of wild boar origin. The estimated recombinant breakpoints comprised epitopes A, B and C of ORF2, without major changes in amino acid sequences. The prevalence of PCV2 in the wild boar population during the 5-year period following the first outbreaks of postweaning multisystemic wasting syndrome (PMWS) in domestic pigs in Romania showed a decrease from 13.4% to 8.3%. To our knowledge, this is the first study to show the existence of ORF2-based intra- and inter-genotype recombination in wild boar populations and the possible recombination between PCV2 strains of wild boars and domestic pigs. Our results suggest a certain independence of PCV2 infection in wild boar populations and demonstrate the possibility of infection with multiple PCV2 genotypes under natural circumstances. On the other hand, PCV2 genotypes specific for wild boars could be detected in domestic pig at lower frequency suggesting the possible spread of wild boar PCV2 to domestic swine. The recombination events described here may contribute to the genetic diversity of PCV2 and may also be the source of emergence of new PCV2 strains.
    Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases 03/2012; 12(2):420-7. · 3.22 Impact Factor
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    ABSTRACT: Potential porcine circovirus type 2 (PCV2) capsid protein epitopes, suitable for expression on the surface of cucumber mosaic virus (CMV) particles were determined by a thorough analysis of the predicted PCV capsid protein structure. The ab initio protein structure prediction was carried out with fold recognition and threading methods. The putative PCV epitopes were selected on the basis of PCV virion models and integrated into the plant virus coat protein, after amino acid position 131. The recombinants were tested for infectivity and stability on different Nicotiana species and stable recombinant virus particles were purified. The particles were tested for their ability to bind to PCV induced porcine antibodies and used for specific antibody induction in mice and pigs. The results showed that PCV epitopes expressed on the CMV surface were recognized by the porcine antibodies and they were also able to induce PCV specific antibody response. Challenge experiment with PCV2 carried out in immunized pigs showed partial protection against the infection. Based on these results it was concluded that specific antiviral vaccine production for the given pathogen was feasible, offering an inexpensive way for the mass production of such vaccines.
    PLoS ONE 01/2012; 7(12):e52688. · 3.73 Impact Factor
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    ABSTRACT: Porcine hokovirus (PHoV), a newly discovered member of the family Parvoviridae and the proposed genus Hokovirus, is considered phylogenetically distinct from other parvoviruses. Here, we report a comprehensive spatio-temporal study of PHoV infection in Romanian wild boars. The prevalence of PHoV differed significantly in samples from 2006/2007 (22.76%) and 2010/2011 (50.54%), and also increased with age. Sequence analysis of PHoVs from 2006/2007 showed a close relationship to PHoVs from pigs from England and wild boars from Germany, while the PHoVs from 2010/2011 were mostly similar to isolates from Hong Kong. The most variable regions were detected in the NS1 gene and proved to be suitable for analysis of the genetic diversity of the virus. It was observed that PHoVs from older wild boar samples differed from those collected recently. These results suggested that porcine hokovirus could be a newly emerging virus of both domestic and wild pigs with yet unknown implications.
    Archives of Virology 10/2011; 156(12):2233-9. · 2.03 Impact Factor
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    ABSTRACT: Pigeon circoviruses (PiCV) had been identified worldwide and are responsible for immune suppression and a variety of diseases collectively referred to as young pigeon disease syndrome. Samples from racing pigeons were collected throughout Hungary and analyzed for the presence of PiCV by polymerase chain reaction. The capsid protein coding gene was amplified from ten PiCVs of different origins, and compared with known PiCV sequences. The results indicated that PiCV was highly variable, the viruses formed five distinct genetic groups. Differences of the 3' end of the gene suggested the possibility of genetic recombination among these groups.
    Virus Genes 09/2011; 44(1):75-9. · 1.77 Impact Factor
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    ABSTRACT: Novel porcine parvoviruses showing the genetic characteristics of bocaviruses have recently been identified. The first such porcine bocavirus (PoBoV1), described as boca-like virus (PBo-likeV), was discovered in PMWS affected pigs in Sweden. Later, several other bocaviruses with divergent genomes were reported under various names in domestic pigs. This is the first report of the presence of bocaviruses in European wild boars. 842 wild boar samples originating from the Western region of Romania (Transylvania) were collected during the 2006/2007 and the 2010/2011 hunting seasons and tested for the presence of PoBoV1 by polymerase chain reaction and sequencing. The results showed 12.94% (109/842) overall positivity, with an increasing prevalence from the 2006/2007 (9.14%, 43/470) to the 2010/2011 (17.74%, 66/372) season (P < 0.01). Differences between the prevalence of the virus in 6-12-month-old-animal (77.06%, 84/109) and 12-36-month-old-animal (22.94%, 25/109) (P < 0.01) indicated that the infection occurred mainly in younger pigs. Comparative sequence analysis of partial VP1/2 genes from wild boars and those available in the GenBank showed only minor differences, indicating that PoBoV1 circulating within the wild boar populations and domestic pigs from different geographic regions were highly similar.
    Virus Genes 08/2011; 43(3):376-9. · 1.77 Impact Factor

Publication Stats

167 Citations
62.43 Total Impact Points

Institutions

  • 2007–2013
    • University of Agricultural Sciences and Veterinary Medicine
      • Faculty of Veterinary Medicine
      Cluj-Napoca, Judetul Cluj, Romania
  • 2006–2013
    • Szent István University, Godollo
      • Department of Microbiology and Infectious Diseases
      Gödöllő, Pest megye, Hungary