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

Lineage diversification, homo- and heterologous reassortment and recombination shape the evolution of chicken orthoreoviruses

The near complete genome sequences of ten field avian orthoreovirus (ARV) strains collected from young chicken between 2002 and 2011 in Hungary have been determined in order to explore the genetic diversity and evolutionary mechanisms affecting ARVs in this region. Sequence analyses and phylogenetic calculations revealed similar geographic distribution and distinct evolution in case of eight studied strains that were closely related to the recently described Hungarian strain T1781. The remaining two strains showed the highest similarity with the US origin AVS-B. The topology of the phylogenetic trees of certain segments was affected by several potential homologous reassortment events between strains of Hungarian, Chinese and US origin. Analyzing the μB gene a possible heterologous reassortment event was identified in three Hungarian strains. Recombination events were detected in as much as a dozen cases implying that beside point mutations and reassorment this mechanism also plays an important role in the diversification of ARVs. All these mechanisms in concert may explain the reduced effectiveness of immunization using commercial vaccine strains

Madarak orthoreovírusainak összehasonlító genomvizsgálata

Avian reoviruses belong to the genus Orthoreovirus. An increasing amount of data is becoming available about these viruses, however, by the time we have started our work, only two near-complete chicken reovirus genome sequences were known. Thus there is only a small amount of data available about the genetic variety of orthoreoviruses found in poultry. Therefore, the main aim of our work was to define the genomic sequences and to analyze the phylogenetic relationship of the virus strains derived from different poultry species

Detection and characterization of a divergent avian reovirus strain from broiler chicken with central nervous system disease

Avian orthoreoviruses have been associated with a variety of diseases in chickens, including tenosynovitis, runting-stunting syndrome, hepatitis, myocarditis, osteoporosis, respiratory diseases, and central nervous system disease. The primary objective of our study was the molecular characterization of an avian reovirus strain, T1781, which was isolated from a broiler chicken with a central nervous system disorder in Hungary during 2012. The complete genome sequence was determined using a traditional sequencing method after cell culture adaptation of the strain. Sequence and phylogenetic analyses showed that T1781 shared only moderate nucleic acid sequence identity in several genes to previously analyzed reovirus strains from chickens, and each gene formed separate branches in the corresponding phylogenetic trees. The maximum nucleotide sequence identities of strain T1781 genes to reference avian reovirus strains ranged from 79 % to 90 %. Collectively, our analyses indicated that T1781 is a divergent chicken reovirus strain. The genetic background of this and other avian reoviruses associated with various disease manifestations needs further investigation