Genome sequences of three turkey orthoreovirus strains isolated in Hungary

We have investigated the genomic properties of three turkey reovirus strains—19831M09, D1246, and D1104—isolated in Hungary in 2009. Sequence identity values and phylogenetic calculations indicated genetic conservativeness among the studied Hungarian strains and a close relationship with strains isolated in the United States

Survey indicates circulation of 4/91 and QX-type infectious bronchitis viruses in Hungary in 2014 — Short communication

Understanding the epidemiology and improving vaccinal protection against the highly variable chicken infectious bronchitis virus (IBV) requires the knowledge of circulating IBV serotypes/genotypes in defined geographic areas. Accordingly, the authors initiated a survey among the major poultry producers in Hungary in order to reveal the prevailing IBV serotypes in the country. Tracheal swabs and organ samples (caecal tonsils, kidneys, and trachea) were collected from broiler, layer, and meat-type breeder flocks, and were subjected to IBV detection by virus isolation and polymerase chain reaction (PCR). The IBV-positive samples were further characterised by nucleotide sequencing and phylogenetic analysis of a portion of the S1 IBV gene. Seventeen out of the 26 submitted samples proved to be positive for IBV. Sequence analyses revealed ten 4/91 and six QX serotypes, and a single D274 type IB virus. One sample contained a mixture of QX and Massachusetts serotype viruses. Presumably most of the 4/91 and D274 type viruses were vaccine strains. The proportion of QX type viruses and their observed variation are in good agreement with the situation in a few other European countries. The detected viruses clustered largely according to their geographic origin, with a few exceptions. If updated regularly, the preliminary ‘virus map’ will be useful for the adjustment of vaccination protocols

Characterization of a PCV2d-2 isolate by experimental infection of pigs

Abstract Porcine circovirus type 2 (PCV2), a highly prevalent, economically important swine pathogen is classified into different genotypes (PCV2a-f) based on phylogenetic analysis. Since the introduction of extensive vaccination programs, at least two major shifts have been observed in the prevalence of PCV2 genotypes. The first genotype shift from 2a towards 2b occurred around 2003, while in recent years, we are witnessing the second change in genotype prevalence from the predominant 2b towards 2d. In this study, a PCV2d-2 isolate was characterized as a potential challenge virus for the evaluation of PCV2 vaccine efficacy. Ten-week-old pigs carrying low to moderate levels of maternally derived antibodies to PCV2 were infected with the isolate by the nasal route. Over the next 4 weeks post-infection, the pigs were monitored for the presence of viremia, fecal virus excretion, and humoral immune responses. At the end of the post-infection observation period, samples were taken from the mediastinal and mesenteric lymph nodes of the animals and tested for viral load. The gradual depletion of maternally derived antibodies in the sera of piglets was demonstrated by ELISA and virus neutralization tests. Following experimental infection by PCV2d-2, specific IgM antibodies were first detected at 14 days post challenge (dpch), while IgG class antibodies were first detected at 21 dpch. Both viremia and virus shedding could be detected at 7 dpch, in 36 and 50% of the pigs, respectively. The proportion of shedders reached 100% by 14 dpch and remained at this level, while viremia was demonstrated in 86, 100, and 100% of the pigs at 14, 21, and 28 dpch, respectively. Both the mediastinal and mesenteric lymph nodes contained high levels of virus (7.6 and 8.5 log10 copies/mg tissue, respectively)

Genome Sequencing of a Novel Variant of Fowl Adenovirus B Reveals Mosaicism in the Pattern of Homologous Recombination Events

We determined the genomic sequence of a Ukrainian strain of fowl adenovirus B (FAdV-B). The isolate (D2453/1) shared 97.2% to 98.4% nucleotide sequence identity with other viruses belonging to the species Fowl aviadenovirus B. Marked genetic divergence was seen in the hexon, fiber, and ORF19 genes, and phylogenetic analysis suggested that recombination events had occurred in these regions. Our analysis revealed mosaicism in the recombination patterns, a finding that has also been described in the genomes of strains of FAdV-D and FAdV-E. The shared recombination breakpoints, affecting the same genomic regions in viruses belonging to different species, suggest that similar selection mechanisms are acting on the key neutralization antigens and epitopes in viruses of different FAdV species