Ákos Boros

Kobuviruses - a comprehensive review.

Kobuviruses are members of the large and growing family Picornaviridae. Until now, two official, Aichi virus and Bovine kobuvirus, and one candidate kobuvirus species, ‘porcine kobuvirus’, have been identified in human, cattle and swine, respectively. In addition, kobu‐like viruses were detected very recently in the bat. Aichi virus could be one of the causative agents of gastroenteritis in humans, and kobuviruses probably also cause diarrhoea in cattle and swine. Although Aichi virus has been detected relatively infrequently (0–3%) in human diarrhoea, high seroprevalence, up to 80–95% at the age of 30–40, was found indicating the general nature of infection in different human populations. In the previous years, much new information has accumulated relating to kobuviruses and their host species. This review summarises the current knowledge on kobuviruses including taxonomy, biology and viral characteristics, and covers all aspects of infection including epidemiology, clinical picture, host species diversity, laboratory diagnosis and it gives a summary about possible future perspectives. Copyright

The Viruses of Wild Pigeon Droppings

Birds are frequent sources of emerging human infectious diseases. Viral particles were enriched from the feces of 51 wild urban pigeons (Columba livia) from Hong Kong and Hungary, their nucleic acids randomly amplified and then sequenced. We identified sequences from known and novel species from the viral families Circoviridae, Parvoviridae, Picornaviridae, Reoviridae, Adenovirus, Astroviridae, and Caliciviridae (listed in decreasing number of reads), as well as plant and insect viruses likely originating from consumed food. The near full genome of a new species of a proposed parvovirus genus provisionally called Aviparvovirus contained an unusually long middle ORF showing weak similarity to an ORF of unknown function from a fowl adenovirus. Picornaviruses found in both Asia and Europe that are distantly related to the turkey megrivirus and contained a highly divergent 2A1 region were named mesiviruses. All eleven segments of a novel rotavirus subgroup related to a chicken rotavirus in group G were sequenced and phylogenetically analyzed. This study provides an initial assessment of the enteric virome in the droppings of pigeons, a feral urban species with frequent human contact.

Identification of a novel astrovirus in a domestic pig in Hungary

The family Astroviridae consists of two genera, Avastrovirus and Mamastrovirus, whose members are associated with gastroenteritis in avian and mammalian hosts, respectively. We serendipitously identified a novel porcine astrovirus in a fecal specimen from a domestic pig (Sus scrofa domestica) in Hungary. Sequencing of a fragment indicated that it was an ORF1b/ORF2/3′UTR sequence, and it has been submitted to the database as porcine astrovirus type 2 (PAstV-2/Hungary/2007) with accession number GU562296. Its unique sequence characteristics and its phylogenetic position suggest that PAstV-2 could be an important link between previously reported astroviruses and that a genetically divergent lineage of astroviruses exist in piglets.

Novel Positive-Sense, Single-Stranded RNA (+ssRNA) Virus with Di-Cistronic Genome from Intestinal Content of Freshwater Carp (Cyprinus carpio)

A novel positive-sense, single-stranded RNA (+ssRNA) virus (Halastavi árva RNA virus, HalV; JN000306) with di-cistronic genome organization was serendipitously identified in intestinal contents of freshwater carps (Cyprinus carpio) fished by line-fishing from fishpond “Lőrinte halastó” located in Veszprém County, Hungary. The complete nucleotide (nt) sequence of the genomic RNA is 9565 nt in length and contains two long - non-in-frame - open reading frames (ORFs), which are separated by an intergenic region. The ORF1 (replicase) is preceded by an untranslated sequence of 827 nt, while an untranslated region of 139 nt follows the ORF2 (capsid proteins). The deduced amino acid (aa) sequences of the ORFs showed only low (less than 32%) and partial similarity to the non-structural (2C-like helicase, 3C-like cystein protease and 3D-like RNA dependent RNA polymerase) and structural proteins (VP2/VP4/VP3) of virus families in Picornavirales especially to members of the viruses with dicistronic genome. Halastavi árva RNA virus is present in intestinal contents of omnivorous freshwater carps but the origin and the host species of this virus remains unknown. The unique viral sequence and the actual position indicate that Halastavi árva RNA virus seems to be the first member of a new di-cistronic ssRNA virus. Further studies are required to investigate the specific host species (and spectrum), ecology and role of Halastavi árva RNA virus in the nature.

Two Closely Related Novel Picornaviruses in Cattle and Sheep in Hungary from 2008 to 2009, Proposed as Members of a New Genus in the Family Picornaviridae

ABSTRACT Two novel picornaviruses were serendipitously identified in apparently healthy young domestic animals—cattle (Bos taurus) and, subsequently, sheep (Ovis aries)—in Hungary during 2008 and 2009. Complete genome sequencing and comparative analysis showed that the two viruses are related to each other and have identical genome organizations, VPg + 5′ UTRIRES-II[L/1A-1B-1C-1D-2ANPG↓P/2B-2C/3A-3BVPg-3Cpro-3Dpol] 3′ UTR-poly(A). We suggest that they form two novel viral genotypes/serotypes, bovine hungarovirus 1 (BHuV-1; GenBank accession number JQ941880) and ovine hungarovirus 1 (OHuV-1; GenBank accession number HM153767), which may belong to a potential novel picornavirus genus in the family Picornaviridae. The genome lengths of BHuV-1 and OHuV-1 are 7,583 and 7,588 nucleotides, each comprising a single open reading frame encoding 2,243 and 2,252 amino acids, respectively. In the 5′ untranslated regions (5′ UTRs), both hungaroviruses are predicted to have a type II internal ribosome entry site (IRES). The nucleotide sequence and the secondary RNA structure of the hungarovirus IRES core domains H-I-J-K-L are highly similar to that of human parechovirus (HPeV) (genus Parechovirus), especially HPeV-3. However, in the polyprotein coding region, the amino acid sequences are more closely related to those of porcine teschoviruses (genus Teschovirus). Hungaroviruses were detected in 15% (4/26) and 25% (4/16) of the fecal samples from cattle and sheep, respectively. This report describes the discovery of two novel picornaviruses in farm animals, cattle and sheep. The mosaic genetic pattern raises the possibility that hungaroviruses, human parechoviruses, and porcine teschoviruses may be linked to each other by modular recombination of functional noncoding RNA elements.

Non-primate hepacivirus infection with apparent hepatitis in a horse — Short communication

Non-primate hepacivirus (NPHV) is a recently identified hepacivirus (family Flaviviridae) in dog and horse; however, the disease associations remain unknown. This study reports the detection of natural NPHV infection in a horse with apparent hepatitis, liver damage and high-level viraemia. NPHV could be hepatotropic and associated with hepatitis in horses.

Astrovirus in wild boars (Sus scrofa) in Hungary

The family Astroviridae consists of two genera, Avastrovirus and Mamastrovirus whose members are associated with gastroenteritis in avian and mammalian hosts, respectively. In this study, we report the first detection of astrovirus from fecal specimens of wild boars (Sus scrofa) using viral metagenomics and complete genome sequencing. The wild boar astrovirus (WBAstV-1/2011/HUN, JQ340310) genome is 6707 nucleotide long and had 76%, 95% and 56% amino acid (aa) identity in the ORF1a (852aa), ORF1b (522aa) and ORF2 (845aa) regions, respectively, to porcine astrovirus 4 (PAstV-4, JF713713), the closest match. This study indicates that wild boar could be a reservoir for astroviruses.

Novel picornavirus in domesticated common quail (Coturnix coturnix) in Hungary

This study reports the detection of a novel picornavirus in domesticated common quail (Coturnix coturnix) in Hungary. The 8159-nucleotide (nt)-long RNA genome of this virus, named quail picornavirus (QPV1-HUN/2010; JN674502), shows only 43%, 39% and 47% amino acid (aa) identity in the P1 (857 aa), P2 (458 aa) and P3 (777 aa) coding regions respectively, to the closest reference, avian sapelovirus. The 5′UTR contains a variant type IV IRES with a 20-nt-long apical “8”-like structure that is conserved in avian-origin and seal picornaviruses. The 390-aa-long L protein is cysteine rich and encodes two copies of a 34-aa-long repeat motif. Quail picornavirus represents a novel picornavirus species and perhaps a novel genus.

Identification of a novel astrovirus in domestic sheep in Hungary

The family Astroviridae consists of two genera, Avastrovirus and Mamastrovirus, whose members are associated with gastroenteritis in avian and mammalian hosts, respectively. We serendipitously identified a novel ovine astrovirus in a fecal specimen from a domestic sheep (Ovis aries) in Hungary by viral metagenomic analysis. Sequencing of the fragment indicated that it was an ORF1b/ORF2/3′UTR sequence, and it has been submitted to the GenBank database as ovine astrovirus type 2 (OAstV-2/Hungary/2009) with accession number JN592482. The unique sequence characteristics and the phylogenetic position of OAstV-2 suggest that genetically divergent lineages of astroviruses exist in sheep.

Avian picornaviruses: Molecular evolution, genome diversity and unusual genome features of a rapidly expanding group of viruses in birds

Picornaviridae is one of the most diverse families of viruses infecting vertebrate species. In contrast to the relative small number of mammal species compared to other vertebrates, the abundance of mammal-infecting picornaviruses was significantly overrepresented among the presently known picornaviruses. Therefore most of the current knowledge about the genome diversity/organization patterns and common genome features were based on the analysis of mammal-infecting picornaviruses. Beside the well known reservoir role of birds in case of several emerging viral pathogens, little is known about the diversity of picornaviruses circulating among birds, although in the last decade the number of known avian picornavirus species with complete genome was increased from one to at least 15. However, little is known about the geographic distribution, host spectrum or pathogenic potential of the recently described picornaviruses of birds. Despite the low number of known avian picornaviruses, the phylogenetic and genome organization diversity of these viruses were remarkable. Beside the common L-4-3-4 and 4-3-4 genome layouts unusual genome patterns (3-4-4; 3-5-4, 3-6-4; 3-8-4) with variable, multicistronic 2A genome regions were found among avian picornaviruses. The phylogenetic and genomic analysis revealed the presence of several conserved structures at the untranslated regions among phylogenetically distant avian and non-avian picornaviruses as well as at least five different avian picornavirus phylogenetic clusters located in every main picornavirus lineage with characteristic genome layouts which suggests the complex evolution history of these viruses. Based on the remarkable genetic diversity of the few known avian picornaviruses, the emergence of further divergent picornaviruses causing challenges in the current taxonomy and also in the understanding of the evolution and genome organization of picornaviruses will be strongly expected. In this review we would like to summarize the current knowledge about the taxonomy, pathogenic potential, phylogenetic/genomic diversity and evolutional relationship of avian picornaviruses.