Search results for "viruses"
showing 10 items of 1182 documents
Assignment of the group A rotavirus NSP4 gene into genotypes using a hemi-nested multiplex PCR assay: a rapid and reproducible assay for strain surve…
2009
The rotavirus non-structural protein NSP4 has been implicated in a number of biological functions during the rotavirus cellular cycle and pathogenesis, and has been addressed as a target for vaccine development. The NSP4 gene has been classified into six genotypes (A–F). A semi-nested triplex PCR was developed for genotyping the major human NSP4 genotypes (A–C), which are common in human rotavirus strains but are also shared among most mammalian rotavirus strains. A total of 192 previously characterized human strains representing numerous G and P type specificities (such as G1P[8], G1P[4], G2P[4], G3P[3], G3P[8], G3P[9], G4P[6], G4P[8], G6P[4], G6P[9], G6P[14], G8P[10], G8P[14], G9P[8], G9P…
Complete genome analysis of contemporary G12P[8] rotaviruses reveals heterogeneity within Wa-like genomic constellation
2016
G12 rotaviruses are globally emergent rotaviruses causing severe childhood gastroenteritis. Little is known about the evolution and diversity of G12P[8] rotaviruses and the possible role that widespread vaccine use, globally, has had on their emergence. In Sicily, Italy, surveillance activity for rotaviruses has been conducted uninterruptedly since 1985, thus representing a unique observatory for the study of human rotaviruses in the pre- and post-vaccine era. G12 rotaviruses were first detected only in 2012 and between 2012 and 2014 they accounted for 8.7% of all rotavirus-associated infections among children, with peaks of 27.8% in 2012/2013 and 21% in 2014. We determined and analyzed the…
Prevalence of group C rotaviruses in weaning and post-weaning pigs with enteritis.
2006
Diarrheic fecal specimens collected from porcine herds were screened for the presence of group C rotaviruses using a reverse transcription-polymerase chain reaction (RT-PCR) assay. A total of 188 samples were tested and 54 were positive. When compiled these data with diagnostic results on group A rotaviruses and enteric caliciviruses we found that all but 5 group C rotavirus positive samples contained at least one additional virus. A subset of samples were subjected to nucleotide sequencing. The selected strains showed an unexpectedly wide range of nucleotide sequence heterogeneity (88.6-100%) to each other and to the reference porcine group C rotavirus strain, Cowden. The nucleotide sequen…
Genetic heterogeneity in the VP7 of group C rotaviruses.
2007
AbstractEvidence for a possible zoonotic role of group C rotaviruses (GCRVs) has been recently provided. To gain information on the genetic relationships between human and animal GCRVs, we sequenced the VP7 gene of 10 porcine strains detected during a large surveillance study from different outbreaks of gastroenteritis in piglets. Four GCRV strains were genetically related to the prototype GCRV porcine Cowden strain. A completely new VP7 genotype included 4 strains (344/04-7-like) that shared 92.5% to 97.0% aa identity to each other, but <83% to human GCRVs and <79% to other porcine and bovine GCRVs. A unique 4-aa insertion (SSSV or SSTI), within a variable region at the carboxy-terminus of…
Diversity and zoonotic potential of rotaviruses in swine and cattle across Europe.
2011
Group A rotaviruses can infect both humans and animals. Individual rotavirus strains can occasionally cross species barriers and might hereby contribute to the emergence of new genotypes in heterologous hosts. The incidence and impact of zoonotic rotavirus are not well defined, and one reason for this is a lack of data about strains circulating in suspected reservoir animal hosts. In this study we report the incidence, genetic diversity, and molecular epidemiology of rotaviruses detected in domestic cattle and swine in 6 European countries. From 2003 to 2007, 1101 and more than 2000 faecal specimens were collected from swine and cattle, both healthy and diarrhoeic, and tested for rotaviruse…
Selection of single-chain antibodies against the VP8* subunit of rotavirus VP4 outer capsid protein and their expression in Lactobacillus casei.
2004
ABSTRACTSingle-chain antibodies (scFv) recognizing the VP8* fraction of rotavirus outer capsid and blocking rotavirus infection in vitro were isolated by phage display. Vectors for the extracellular expression inLactobacillus caseiof one of the scFv were constructed.L. caseiwas able to secrete active scFv to the growth medium, showing the potential of probiotic bacteria to be engineered to express molecules suitable for in vivo antirotavirus therapies.
Detection of a porcine-like rotavirus in a child with enteritis in Italy.
2008
ABSTRACT During a 1-year rotavirus surveillance of children hospitalized with acute gastroenteritis in Brescia Hospital, Italy, a chimerical rotavirus strain, G3P[6], was detected, displaying the VP7 and VP4 genes of porcine origin and the NSP4 and VP6 genes of human origin. The reassortant nature of the virus rules out a direct zoonotic event.
Single-chain variable fragment (scFv) antibodies against rotavirus NSP4 enterotoxin generated by phage display.
2004
The rotavirus non-structural NSP4 protein causes membrane destabilization as well as an increase in intracellular calcium levels in eukaryotic cells and induces diarrhea in young mice, acting as a viral enterotoxin. In this study the phage display technique was used to generate a panel of single-chain variable fragment (scFv) antibodies specific for the NSP4 protein of the human rotavirus strain Wa from a human semi-synthetic scFv library. After several rounds of panning and selection on NSP4 adsorbed to polystyrene tubes, individual scFv were isolated and characterised by fingerprinting and by sequencing the VH and VL genes. The isolated scFv antibodies specifically recognize NSP4 in enzym…
Crystallization and Preliminary X-Ray Analysis of Rotavirus Protein VP6
1998
ABSTRACT As a first step to gain insight into the structure of the rotavirus virion at atomic resolution, we report here the expression, purification, and crystallization of recombinant rotavirus protein VP6. This protein has the property of polymerizing in the form of tubular structures in solution which have hindered crystallization thus far. Using a combination of electron microscopy and small-angle X-ray scattering, we found that addition of Ca 2+ at concentrations higher than 100 mM results in depolymerization of the tubes, leading to an essentially monodisperse solution of trimeric VP6 even at high protein concentrations (higher than 10 mg/ml), thereby enabling us to search for crysta…
Rotavirus-Specific Cytotoxic T Lymphocytes Recognize Overlapping Epitopes in the Amino-Terminal Region of the VP7 Glycoprotein
1999
Abstract Rotavirus-specific cytotoxic T lymphocytes (CTL) play an important role in the resolution of rotavirus infection. The outer capsid glycoprotein, VP7, elicits a class I MHC-restricted CTL response. Vaccinia virus recombinants expressing the VP7 genes from simian rotavirus SA11 (serotype G3) and from the RF strain of bovine rotavirus (serotype G6) were used to analyze the CTL activity to this antigen in BALB/c (H-2 d ) and C57BL/6 (H-2 b ) mice neonatally infected with homologous and heterologous rotaviruses. A vaccinia virus recombinant expressing the first amino-terminal 88 amino acids of VP7 was constructed and used to search for cross-reactive CTL against this region of the prote…