Search results for "Rotaviru"
showing 10 items of 175 documents
Molecular characterization of rotavirus strains from children with diarrhea in Italy, 2007-2009.
2011
The surveillance network RotaNet-Italia was established in 2007 in order to investigate the diversity of co-circulating rotavirus strains in Italy, and to provide a baseline for future assessment of possible effects of vaccine implementation in selecting novel versus common rotavirus strains. A total of 2,645 rotavirus strains from pediatric patients with acute diarrhea were collected over three consecutive seasons from September 2006 through August 2009, and partially characterized by standardized multiplex RT-PCR. Most of strains (89.1%) belonged to genotypes G1–G4, and G9, associated with either P[8] or P[4], commonly found in humans worldwide. However, in at least 2.0% of cases, viruses…
Expression and purification of polyhistidine-tagged rotavirus NSP4 proteins in insect cells
2003
The rotavirus nonstructural NSP4 protein, a transmembrane endoplasmic reticulum-specific glycoprotein, has been described as the first viral enterotoxin. Purified NSP4 or a peptide corresponding to NSP4 residues 114-135 induces diarrhea in young mice. NSP4 has a membrane-destabilizing activity and causes an increase in intracellular calcium levels and chloride secretion by a calcium-dependent signalling pathway in eucaryotic cells. In this study, four recombinant baculoviruses were generated expressing the rotavirus NSP4 glycoprotein from the human strains Wa and Ito, the porcine strain OSU, and the simian strain SA11, which belong to two different NSP4 genotypes, A and B. The recombinant g…
Homotypic Protection Against Rotavirus-Induced Diarrhea in Infant Mice Breast-Fed by Dams Immunized with the Recombinant VP8* Subunit of the VP4 Caps…
2000
The outer capsid proteins VP4 and VP7 induce neutralizing antibody against rotavirus. We have investigated in a mouse model the protection mediated by immunization with VP8*, the amino-terminal tryptic fragment of VP4. BALB/c female mice immunized with simian rotavirus SA11 VP6 and VP8* proteins expressed in Escherichia coli were mated with seronegative males. Litters were orally challenged with the SA11 strain (P5B[2], G3) or with the murine rotavirus strain EDIM (P10[16], G3) to verify the degree of protection against diarrhea induced in the newborns. Only those pups born to dams immunized with VP8* did not develop diarrhea after having been orally challenged with the SA11 strain. Pups bo…
Identification of a novel VP4 genotype carried by a serotype G5 porcine rotavirus strain
2006
AbstractRotavirus genome segment 4, encoding the spike outer capsid VP4 protein, of a porcine rotavirus (PoRV) strain, 134/04-15, identified in Italy was sequenced, and the predicted amino acid (aa) sequence was compared to those of all known VP4 (P) genotypes. The aa sequence of the full-length VP4 protein of the PoRV strain 134/04-15 showed aa identity values ranging from 59.7% (bovine strain KK3, P8[11]) to 86.09% (porcine strain A46, P[13]) with those of the remaining 25 P genotypes. Moreover, aa sequence analysis of the corresponding VP8* trypsin cleavage fragment revealed that the PoRV strain 134/04-15 shared low identity, ranging from 37.52% (bovine strain 993/83, P[17]) to 73.6% (po…
Rotavirus Genotypes in Sewage Treatment Plants and in Children Hospitalized with Acute Diarrhea in Italy in 2010 and 2011
2014
ABSTRACT Although the molecular surveillance network RotaNet-Italy provides useful nationwide data on rotaviruses causing severe acute gastroenteritis in children in Italy, scarce information is available on rotavirus circulation in the general Italian population, including adults with mild or asymptomatic infection. We investigated the genotypes of rotaviruses present in urban wastewaters and compared them with those of viral strains from clinical pediatric cases. During 2010 and 2011, 285 sewage samples from 4 Italian cities were tested by reverse transcription-PCRs (RT-PCRs) specific for rotavirus VP7 and VP4 genes. Rotavirus was detected in 172 (60.4%) samples, 26 of which contained mul…
VP7 and VP4 Sequence Analyses of Rotavirus Strains From Italian Children With Viraemia and Acute Diarrhoea
2010
Background: Rotavirus has a high genetic variability. Point mutations, accumulating at a high rate, and genetic reassortment events have been well-documented. Viremia occurs commonly in children with acute rotavirus diarrhoea. However, information on genetic characterization of strains associated with systemic infection is poor. Objective: We evaluated prospectively children hospitalized for acute rotavirus diarrhoea and genotyped strains obtained from blood and stool samples. Nucleotide sequences within the VP4 ad VP7 genes of strains obtained from blood and stool specimens of the same patient were compared. Methods: Study subjects were 11 children admitted with acute rotavirus diarrhoea, …
Enteric calicivirus and rotavirus infections in domestic pigs
2009
SUMMARYWe report the prevalence of rotavirus and calicivirus infections, along with their respective association with diarrhoea in the porcine population of the region of northern Spain. A total of 221 samples were collected at random from different farms in the region and from the main slaughterhouse facility in the city of Zaragoza. Faecal samples were scored as diarrhoeic or normal and grouped into five groups to match general farm management and age criteria: group I (suckling 0–4 weeks), group II (weaning >4–8 weeks), group III (transition >8–16 weeks), group IV (fattening >16–24 weeks) and group V (adults >24 weeks). Group A rotavirus detection and caliciviruses were inves…
Genetic heterogeneity of porcine enteric caliciviruses identified from diarrhoeic piglets
2008
Enteric caliciviruses (noroviruses and sapoviruses) are responsible for the majority of non-bacterial gastroenteritis in humans of all age groups. Analysis of the polymerase and capsid genes has provided evidence for a huge genetic diversity, but the understanding of their ecology is limited. In this study, we investigated the presence of porcine enteric caliciviruses in the faeces of piglets with diarrhoea. A total of 209 samples from 118 herds were analysed and calicivirus RNA was detected by RT-PCR in 68 sample (32.5%) and in 46 herds (38.9%), alone or in mixed infection with group A and C rotaviruses. Sequence and phylogenetic analysis of the calicivirus-positive samples characterized t…
Distribution of VP7 serotypes and VP4 genotypes among rotavirus strains recovered from Italian children with diarrhea
1997
108 rotavirus strains obtained from children with diarrhea hospitalized in Palermo, Italy, in the years 1990-1994, were examined by seminested PCR to study the relative frequency and distribution of the four most common alleles of the gene 4. Such strains were selected from 344 human rotavirus strains recovered in palermo during those years after characterization by electropherotyping, subgrouping and G serotyping. One hundred and seven of the 108 strains could be classified into P types, the P[8], G1 (38.3%) and the P[8], G4 (52.3%) types being predominant. The unique strain whose P genotype could not be identified showed an unusual combination of long migration electrophoretic pattern and…
Electropherotyping of human rotaviruses: An epidemiological survey of rotavirus infections in Sicily
1986
An electrophoretic analysis of rotavirus RNA segments was carried out on 522 faecal specimens, obtained from children hospitalized in Sicily in the period 1981/85. One hundred and one viral isolates could be characterized with respect to the electrophoretic pattern of their genomic RNAs. This analysis revealed that in 1981/82 different electropherotypes cocirculated in the infant population. In 1983 one of the patterns became prevalent; in 1984/85 only one electropherotype was detected, both in Palermo and Catania specimens. The serotyping showed that all viral strains with the prevalent electropherotype were subgroup II and serotype 1. These results contrast with the extensive genome varia…