Search results for "viruses"
showing 10 items of 1182 documents
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.
Emergence in 2017-2019 of novel reassortant equine-like G3 rotavirus strains in Palermo, Sicily.
2021
Rotavirus A (RVA) is a major etiologic agent of gastroenteritis in children worldwide. Hospital-based surveillance of viral gastroenteritis in paediatric population in Palermo (Italy) from 2017 onwards revealed a sharp increase in G3P[8] RVAs, accounting for 71% of all the RVAs detected in 2019. This pattern had not been observed before in Italy, with G3 RVA usually being detected at rates lower than 3%. In order to investigate this unique epidemiological pattern, the genetic diversity of G3 RVAs identified during a 16-year long surveillance (2004-2019) was explored by systematic sequencing of the VP7 and VP4 genes and by whole genome sequencing of selected G3 strains, representative of the…
A feline rotavirus G3P[9] carries traces of multiple reassortment events and resembles rare human G3P[9] rotaviruses.
2011
The full-length genome sequence of a feline G3P[9] rotavirus (RV) strain, BA222, identified from the intestinal content of an adult cat, was determined. Strain BA222 possessed a G3-P[9]-I2-R2-C2-M2-A3-N1-T3-E2-H3 genomic constellation, differing substantially from other feline RVs. Phylogenetic analyses of each genome segment revealed common origins with selected animal and zoonotic human RVs, notably with rare multi-reassortant human G3P[9] RVs (Ita/PAI58/96 and Ita/PAH136/96). Altogether, the findings suggest that feline RVs are genetically diverse and that human RVs may occasionally originate either directly or indirectly (via reassortment) from feline RVs.
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.
Inhibition of in vitro reconstitution of rotavirus transcriptionally active particles by anti-VP6 monoclonal antibodies
1994
International audience; Six monoclonal antibodies specific for the major capsid protein of rotavirus, VP6, previously characterized, were tested in a biological assay for their capacity to block the transcriptase activity associated with the single-shelled particles. The results showed that two MAbs (RV-50 and RV-133), specific for distinct antigenic sites, were able to block the transcription when they were incubated with a purified baculovirus-expressed group A VP6, prior to the reconstitution of the single-shelled particles from the cores, suggesting that at least two domains are involved in active single-shelled particle reconstitution. The results obtained previously from immunochemist…
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 …