RotaC: A web-based tool for the complete genome classification of group A rotaviruses

<p>Abstract</p> <p>Background</p> <p>Group A rotaviruses are the most common cause of severe diarrhea in infants and children worldwide and continue to have a major global impact on childhood morbidity and mortality. In recent years, considerable research efforts have been devoted to the development of two new live, orally administered vaccines. Although both vaccines have proven to confer a good protection against severe rotavirus gastroenteritis, these vaccines will have to be screened and may have to be updated regularly to reflect temporal and spatial genotype fluctuations. In this matter, the genetic characterization of circulating and new emerging rotavirus strains will need to be compulsory and accurate. An extended classification system for rotaviruses in which all the 11 genomic RNA segments are used, has been proposed recently. The use of this classification system will help to elucidate the role of gene reassortments in the generation of genetic diversity, host range restriction, co-segregation of certain gene segments, and in adaptation to a new host species.</p> <p>Results</p> <p>Here we present a web-based tool that can be used for fast rotavirus genotype differentiation of all 11 group A rotavirus gene segments according to the new guidelines proposed by the <it>Rotavirus Classification Working Group </it>(RCWG).</p> <p>Conclusion</p> <p>With the increasing sequencing efforts that are being conducted around the world to unravel complete rotavirus genomes of human and animal origin, this tool will be of great help to analyze and correctly classify the large amount of new data. The web-based tool is freely available at <url>http://rotac.regatools.be</url>.</p

Unusual Assortment of Segments in 2 Rare Human Rotavirus Genomes

Using full-length genome sequence analysis, we investigated 2 rare G3P[9] human rotavirus strains isolated from children with diarrhea. The genomes were recognized as assortments of genes closely related to rotaviruses originating from cats, ruminants, and humans. Results suggest multiple transmissions of genes from animal to human strains of rotaviruses

Rotavirus NSP1 contributes to intestinal viral replication, pathogenesis, and transmission

Rotavirus (RV)-encoded nonstructural protein 1 (NSP1), the product of gene segment 5, effectively antagonizes host interferon (IFN) signaling via multiple mechanisms. Recent studies with the newly established RV reverse genetics system indicate that NSP1 is not essential for the replication of the simian RV SA11 strain in cell culture. However, the role of NSP1 in RV infectio

Complete genome sequence of a porcine epidemic diarrhea virus from a novel outbreak in Belgium, January 2015

Porcine epidemic diarrhea virus (PEDV) is a member of the family Coronaviridae and can cause severe outbreaks of diarrhea in piglets from different age groups. Here, we report the complete genome sequence (28,028 nt) of a PEDV strain isolated during a novel outbreak in Belgium

Honey-bee-associated prokaryotic viral communities reveal wide viral diversity and a profound metabolic coding potential

Honey bees (Apis mellifera) produce an enormous economic value through their pollination activities and play a central role in the biodiversity of entire ecosystems. Recent efforts have revealed the substantial influence that the gut microbiota exert on bee development, food digestion, and homeostasis in general. In this study, deep sequencing was used to characterize prokaryotic viral communities associated with honey bees, which was a blind spot in research up until now. The vast majority of the prokaryotic viral populations are novel at the genus level, and most of the encoded proteins comprise unknown functions. Nevertheless, genomes of bacteriophages were predicted to infect nearly every major bee-gut bacterium, and functional annotation and auxiliary metabolic gene discovery imply the potential to influence microbial metabolism. Furthermore, undiscovered genes involved in the synthesis of secondary metabolic biosynthetic gene clusters reflect a wealth of previously untapped enzymatic resources hidden in the bee bacteriophage community

Metagenomic approach with the NetoVIR enrichment protocol reveals virus diversity within Ethiopian honey bees (Apis mellifera simensis)

Metagenomics studies have accelerated the discovery of novel or divergent viruses of the honey bee. However, most of these studies predominantly focused on RNA viruses, and many suffer from the relatively low abundance of viral nucleic acids in the samples (i.e., compared to that of the host). Here, we explored the virome of the Ethiopian honey bee, Apis mellifera simensis, using an unbiased metagenomic approach in which the next-generation sequencing step was preceded by an enrichment protocol for viral particles. Our study revealed five well-known bee viruses and 25 atypical virus species, most of which have never been found in A. mellifera before. The viruses belong to Iflaviridae, Dicistroviridae, Secoviridae, Partitiviridae, Parvoviridae, Potyviridae, and taxonomically unclassified families. Fifteen of these atypical viruses were most likely plant-specific, and the remaining ten were presumed to be insect-specific. Apis mellifera filamentous virus (AmFV) was found in one sampling site out of 10. Two samples contained high read counts of a virus similar to Diatraea saccharales densovirus (DsDNV), which is a virus that causes high mortality in the sugarcane borer. AmFV and the DsDNV-like virus were the only DNA viruses found. Three viruses that primarily infect Drosophila spp. were also discovered: La Jolla virus (LJV), Kilifi virus (KiV), and Thika virus. Our study suggests that phoretic varroa mites are involved in the transmission of LJV and KiV and that both viruses replicate in mites and adult bees. We also found an overwhelming dominance of the deformed wing virus type B variant, which fits well with the apparently harmless infestation by Varroa destructor. It was suggested that Ethiopian bees have developed tolerance against virus infections as the result of natural selection

Highly divergent CRESS DNA and picorna-like viruses associated with bleached thalli of the green seaweed <i>Ulva</i>

Marine macroalgae (seaweeds) are important primary producers and foundation species in coastal ecosystems around the world. Seaweeds currently contribute to an estimated 51% of the global mariculture production, with a long-term growth rate of 6% per year, and an estimated market value of more than US$11.3 billion. Viral infections could have a substantial impact on the ecology and aquaculture of seaweeds, but surprisingly little is known about virus diversity in macroalgal hosts. Using metagenomic sequencing, we characterized viral communities associated with healthy and bleached specimens of the commercially important green seaweed Ulva. We identified 20 putative new and divergent viruses, of which the majority belonged to the Circular Rep-Encoding Single-Stranded (CRESS) DNA viruses [single-stranded (ss)DNA genomes], Durnavirales [double-stranded (ds)RNA], and Picornavirales (ssRNA). Other newly identified RNA viruses were related to the Ghabrivirales, the Mitoviridae, and the Tombusviridae. Bleached Ulva samples contained particularly high viral read numbers. While reads matching assembled CRESS DNA viruses and picorna-like viruses were nearly absent from the healthy Ulva samples (confirmed by qPCR), they were very abundant in the bleached specimens. Therefore, bleaching in Ulva could be caused by one or a combination of the identified viruses but may also be the result of another causative agent or abiotic stress, with the viruses simply proliferating in already unhealthy seaweed tissue. This study highlights how little we know about the diversity and ecology of seaweed viruses, especially in relation to the health and diseases of the algal host, and emphasizes the need to better characterize the algal virosphere. IMPORTANCE Green seaweeds of the genus Ulva are considered a model system to study microbial interactions with the algal host. Remarkably little is known, however, about viral communities associated with green seaweeds, especially in relation to the health of the host. In this study, we characterized the viral communities associated with healthy and bleached Ulva. Our findings revealed the presence of 20 putative novel viruses associated with Ulva, encompassing both DNA and RNA viruses. The majority of these viruses were found to be especially abundant in bleached Ulva specimens. This is the first step toward understanding the role of viruses in the ecology and aquaculture of this green seaweed.</p

Nanopore sequencing as a revolutionary diagnostic tool for porcine viral enteric disease complexes identifies porcine kobuvirus as an important enteric virus

Enteric diseases in swine are often caused by different pathogens and thus metagenomics are a useful tool for diagnostics. The capacities of nanopore sequencing for viral diagnostics were investigated here. First, cell culture-grown porcine epidemic diarrhea virus and rotavirus A were pooled and sequenced on a MinION. Reads were already detected at 7 seconds after start of sequencing, resulting in high sequencing depths (19.2 to 103.5X) after 3 h. Next, diarrheic feces of a one-week-old piglet was analyzed. Almost all reads (99%) belonged to bacteriophages, which may have reshaped the piglet's microbiome. Contigs matched Bacteroides, Escherichia and Enterococcus phages. Moreover, porcine kobuvirus was discovered in the feces for the first time in Belgium. Suckling piglets shed kobuvirus from one week of age, but an association between peak of viral shedding (10(6.42)-10(7.01) copies/swab) and diarrheic signs was not observed during a follow-up study. Retrospective analysis showed the widespread (n = 25, 56.8% positive) of genetically moderately related kobuviruses among Belgian diarrheic piglets. MinION enables rapid detection of enteric viruses. Such new methodologies will change diagnostics, but more extensive validations should be conducted. The true enteric pathogenicity of porcine kobuvirus should be questioned, while its subclinical importance cannot be excluded

A single bat species in Cameroon harbors multiple highly divergent papillomaviruses in stool identified by metagenomics analysis

AbstractA number of PVs have been described in bats but to the best of our knowledge not from feces. Using a previously described NetoVIR protocol, Eidolon helvum pooled fecal samples (Eh) were treated and sequenced by Illumina next generation sequencing technology. Two complete genomes of novel PVs (EhPV2 and EhPV3) and 3 partial sequences (BATPV61, BATPV890a and BATPV890b) were obtained and analysis showed that the EhPV2 and EhPV3 major capsid proteins cluster with and share 60–64% nucleotide identity with that of Rousettus aegyptiacus PV1, thus representing new species of PVs within the genus Psipapillomavirus. The other PVs clustered in different branches of our phylogenetic tree and may potentially represent novel species and/or genera. This points to the vast diversity of PVs in bats and in Eidolon helvum bats in particular, therefore adding support to the current concept that PV evolution is more complex than merely strict PV-host co-evolution

Experimental feline enteric coronavirus infection reveals an aberrant infection pattern and shedding of mutants with impaired infectivity in enterocyte cultures

Feline infectious peritonitis (FIP) results from mutations in the viral genome during a common feline enteric coronavirus (FECV) infection. Since many virological and immunological data on FECV infections are lacking, the present study investigated these missing links during experimental infection of three SPF cats with FECV strain UCD. Two cats showed mild clinical signs, faecal shedding of infectious virus from 4 dpi, a cell-associated viraemia at inconsistent time points from 5 dpi, a highly neutralising antibody response from 9 dpi, and no major abnormalities in leukocyte numbers. Faecal shedding lasted for 28-56 days, but virus shed during this stage was less infectious in enterocyte cultures and affected by mutations. Remarkably, in the other cat neither clinical signs nor acute shedding were seen, but virus was detected in blood cells from 3 dpi, and shedding of non-enterotropic, mutated viruses suddenly occurred from 14 dpi onwards. Neutralising antibodies arose from 21 dpi. Leukocyte numbers were not different compared to the other cats, except for the CD8(+) regulatory T cells. These data indicate that FECV can infect immune cells even in the absence of intestinal replication and raise the hypothesis that the gradual adaptation to these cells can allow non-enterotropic mutants to arise