Search results for " secretion"
showing 10 items of 490 documents
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.
Evaluation of reverse transcription and polymerase chain reaction (RT/PCR) for the detection of rotaviruses: applications of the assay.
1996
Summary Our aim was to evaluate the reverse transcription and polymerase chain reaction (RT/PCR) technique for the detection of rotavirus shedding by infected children as a routine diagnostic procedure, in comparison to the enzyme-linked immunosorbent assay (ELISA), electron microscopy (EM) and polyacrylamide gel etectrophoresis (PAGE) of rotavirus double stranded RNA. Two-hundred and twenty stool specimens were collected from infants and young children with diarrhoea, and 10–20% faecal suspensions were made. Several methods of rotavirus dsRNA extraction were assayed. Electrophoretic analysis of viral RNA was carried out on 10% polyacrylamide gols followed by silver staining. RT/PCR was per…
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…
Heterogeneity and temporal dynamics of evolution of G1 human rotaviruses in a settled population.
2006
ABSTRACT A rotavirus sample collection from 19 consecutive years was used to investigate the heterogeneity and the dynamics of evolution of G1 rotavirus strains in a geographically defined population. Phylogenetic analysis of the VP7 gene sequences of G1P[8] human rotavirus strains showed the circulation of a heterogeneous population comprising three lineages and seven sublineages. Increases in the circulation of G1 rotaviruses were apparently associated with the introduction of novel G1 strains that exhibited multiple amino acid changes in antigenic regions involved in rotavirus neutralization compared to the strains circulating in the previous years. The emergence and/or introduction of G…
Molecular characterization of the genotype G9 human rotavirus strains recovered in Palermo, Italy, during the winter of 1999-2000
2004
Among the known human rotavirus serotypes, types G1–G4 are ubiquitous and account for >80% of global human rotavirus strains. Since 1994 an increase in reports of G9 serotype isolates has been observed in both developed and developing countries. In the winter season of 1999–2000 we detected the appearance of G9 rotavirus in Palermo, Italy, accounting for 19% of all rotaviruses circulating in our geographical area. Some of these Italian G9 isolates have been submitted to partial sequencing of their VP7 gene. All of them showed complete nucleotide identity suggesting a clonal origin. The Italian VP7 sequences were found to be very closely related to that of other G9 strains recently isolat…
Sequence analysis of the VP7 and VP4 genes identifies a novel VP7 gene allele of porcine rotaviruses, sharing a common evolutionary origin with human…
2005
AbstractDuring an epidemiological survey encompassing several porcine herds in Saragoza, Spain, the VP7 and VP4 of a rotavirus-positive sample, 34461-4, could not be predicted by using multiple sets of G- and P-type-specific primers. Sequence analysis of the VP7 gene revealed a low amino acid (aa) identity with those of well-established G serotypes, ranging between 58.33% and 88.88%, with the highest identity being to human G2 rotaviruses. Analysis of the VP4 gene revealed a P[23] VP4 specificity, as its VP8* aa sequence was 95.9% identical to that of the P14[23],G5 porcine strain A34, while analysis of the VP6 indicated a genogroup I, that is predictive of subgroup I specificity. Analysis …
Canine-Origin G3P[3] Rotavirus Strain in Child with Acute Gastroenteritis
2007
Infection by an animal-like strain of rotavirus (PA260/97) was diagnosed in a child with gastroenteritis in Palermo, Italy, in 1997. Sequence analysis of VP7, VP4, VP6, and NSP4 genes showed resemblance to a G3P[3] canine strain identified in Italy in 1996. Dogs are a potential source of human viral pathogens.
Genetic characterization of G3 rotaviruses detected in Italian children in the years 1993–2005
2009
International audience; In recent years an apparent increase in the frequency of detection of G3P[8] rotaviruses has been observed worldwide. Similarly, in Italy G3P[8] strains have been detected sporadically and in a scattered fashion over 20 years, whereas in 2003 and 2005 G3P[8] rotavirus activity increased markedly. By analysis of the VP7, VP4, VP6 and NSP4 genes of a selection of G3P[8] rotaviruses detected between 1993 and 2005, a remarkable sequence conservation was observed in the VP7, VP4 and VP6 genes. By converse, after 2002 the Italian G3P[8] strains were found to possess unique mutations in significant regions of the NSP4 protein.
Inhibitory Activities of Bovine Macromolecular Whey Proteins on Rotavirus Infections In Vitro and In Vivo
2006
Rotavirus is a major cause of infantile viral gastroenteritis and can lead to severe and sometimes lethal dehydration. Previous studies have shown that breast-fed children are better protected against symptomatic infections, and that the milk fat globule protein lactadherin might be at least partly responsible for this effect. In vitro studies have shown that human lactadherin, in contrast to the bovine ortholog, could inhibit rotavirus infectivity, and that bovine MUC1 and a commercially available bovine macromolecular whey protein (MMWP) fraction proved to be effective. The present work describes the versatility of MMWP against the infection of 2 human intestinal cell lines (Caco-2 and FH…
Unexpected substitution of dominant rotavirus G genotypes in French hospitalized children over five consecutive seasons.
2009
International audience; The study was designed to evaluate the circulation of group A rotaviruses in French hospitalized children, and to detect unusual strains. This prospective study was conducted from 2001 to 2006 in children consulting for acute diarrhea at the pediatric emergency department in three French University Hospitals. The rotaviruses were detected by rapid test and genotyped by RT-PCR on the basis of their outer capsid proteins VP4 (P-type) and VP7 (G-type). The stools from 757 children were analyzed. G1P[8] strains were predominant (44.0%), followed by G9P[8] (17.7%), G3P[8] 13.1%, G4P[8] (9.5%), and G2P[4] (1.8%); mixed rotavirus infections occurred in 2.3%. G9 rotaviruses …