An emerging new fowl adenovirus genotype

Abstract

In this work, we examined the diversity of fowl adenovirus (FAdV) types occurring in Hungary. From diseased chicken flocks in Eastern Hungary, 29 FAdV strains were isolated between 2011 and 2015. We performed molecular typing of the isolates based on their partial hexon sequences. The results showed that representatives from every FAdV species from A to E are present in Hungary, but compared to the findings from our previous survey, a lower number of different FAdV types were detected. Inclusion body hepatitis was always associated with FAdV-2 or -8b, gizzard erosion was caused in almost every case by FAdV-1. Numerous strains belonging to species FAdV-B were found. The complete genome sequence of a candidate new genotype strain, showing the highest divergence from the reference FAdV-5, was determined using next generation sequencing. In order to provide results compatible with the serology-based type classification, multiple genomic regions, including the major antigenic determinants, of the new isolate (strain 40440-M/2015) were compared to their counterparts in the prototype FAdV-5 (strain 340) from species FAdV-B, at both nucleotide and amino acid sequence levels. In different comparative analyses, the two strains were always found to have larger divergence between each other than any two of the most closely related FAdV serotypes. This new emerging FAdV genotype is already present in Hungary and Austria, though its exact pathological role requires further investigations. The introduction of a novel FAdV (geno)type for the classification of these strains is further supported.

Fowl Adenovirus (FAdV) Recombination with Intertypic Crossovers in Genomes of FAdV-D and FAdV-E, Displaying Hybrid Serological Phenotypes

“…The most notable divergence between FAdV-3 and other type members existed in ORF19. Similar to a recent finding in FAdV-B [69], this gene (and its predicted protein) was as divergent within the species as from its closest relative of another species, possibly suggesting that it had been derived in independent events from a reservoir outside the species.…”

Adenoviruses across the animal kingdom: a walk in the zoo

“…FAdV‐1 has been reported several times from birds other than chickens, including quail and Alagoas curassow, a pheasant‐like bird, the wild populations of which became extinct. Nowadays, novel FAdV types are reported exceptionally rarely; however, several strains showing significant divergence from FAdV‐5 were just described in Central Europe as candidate type FAdV‐13 . During metagenomics studies on fecal samples from Australian wild birds, partial sequences of an aviadenovirus were identified in Pacific black duck .…”

Contribution of Viral Genomic Diversity to Oyster Susceptibility in the Pacific Oyster Mortality Syndrome

“…The wild oyster populations of the Atlantic are likely to be reservoirs of viruses with a higher genetic diversity than the cultured populations of the Thau lagoon, as indicated by previous studies showing a lower viral diversity in hatchery−reared oysters relative to wild individuals ( Vendrami et al, 2019 ). In full support of these observations, a higher host genetic diversity is expected to generate a higher viral diversity since viruses are obligatory cellular parasites, which implies that the virus and the host partners reciprocally affect each other’s evolution ( Kajan et al, 2019 ). Regardless of the origin of this diversity, our analysis revealed that the OsHV-1 μVar diversity along French coasts is higher than previously described ( Burioli et al, 2018 ).…”