| genomic diversity of small round structured viruses in the united kingdom. | fifty-two faecal specimens collected in the united kingdom between 1986 and 1992, which contained small round structured virus (srsv) particles, were tested by reverse transcriptase polymerase chain reaction assays using two primer pairs derived from sequences of snow mountain agent and norwalk virus. there was poor correlation between results obtained with each primer pair. twenty specimens (38%) gave positive bands with sm51/31 primers and 18 (34%) were positive with sm52/32 primers, with a to ... | 1994 | 7852972 |
| molecular characterization of hawaii virus and other norwalk-like viruses: evidence for genetic polymorphism among human caliciviruses. | hawaii virus (hv), from a 1971 family outbreak of gastroenteritis, is serotypically distinct from norwalk virus (nv), recently identified as a human calicivirus by molecular analysis. about 2600 consecutive nucleotides of the hv genome (including those encoding the viral capsid protein) and part of the polymerase region of three other viruses (mdv1, mdv6 and sv7) were sequenced. comparison of the amino acid sequence of the capsid protein of hv with nv and other human caliciviruses (toronto virus ... | 1994 | 8077710 |
| sequence and genome organization of a human small round-structured (norwalk-like) virus. | small round-structured viruses (srsvs), also known as norwalk or norwalk-like viruses, are the major worldwide cause of acute, epidemic nonbacterial gastroenteritis in humans. these viruses, which contain a single-stranded rna genome, have remained refractory to molecular characterization because of the small amounts of virus in clinical samples and the absence of an animal model and an in vitro culture system. the complete genomic nucleotide sequence of an srsv, southampton virus, was determine ... | 1993 | 8380940 |
| a conserved sequence motif at the 5' terminus of the southampton virus genome is characteristic of the caliciviridae. | we have determined the 5'terminal cdna sequence for the genome of southampton virus, a recently characterized, human, small round-structured virus (srsv). genomic rna was extracted directly from a stool sample and amplified by rt-pcr by homopolymer tailing of the 3' terminus of the cdna. the additional sequence increases the overall length of the southampton virus genome by 12 nucleotides, resulting in a significant change to the genome organization by extending the first large open reading fram ... | 1995 | 8560774 |
| polyprotein processing in southampton virus: identification of 3c-like protease cleavage sites by in vitro mutagenesis. | a genomic clone of the small, round-structured virus southampton virus (sv) was constructed from a set of overlapping pcr amplicons. sequence analysis confirmed the absence of mutations and accurate ligation of the pcr products. the sv cdna was cloned into a vector for in vitro production of rna and subsequent translation by rabbit reticulocyte lysate. two polypeptides corresponding to the n-terminal and c-terminal regions of the viral polyprotein were expressed in escherichia coli and used to p ... | 1996 | 8642693 |
| completion of the norwalk virus genome sequence. | norwalk virus (nv) is the prototype human calicivirus, and causes epidemic outbreaks of acute gastroenteritis. the sequence and predicted genome organization of nv and a nv-like virus [southampton virus (shv)] suggested they are similar viruses at the nucleotide and amino acid level, although shv was reported to be antigenically distinct from nv. a recent review described the discovery of an additional 12 nucleotides at the 5' end of shv and prompted us to investigate the possibility of addition ... | 1996 | 8883366 |
| molecular epidemiology of outbreaks of gastroenteritis associated with small round-structured viruses in east anglia, united kingdom, during the 1996-1997 season. | during the winter season from november 1996 to may 1997, 550 fecal specimens were submitted from 94 outbreaks of gastroenteritis occurring in east anglia, united kingdom. these specimens were tested for the presence of small round-structured viruses (srsvs) by electron microscopy, reverse transcriptase pcr, or both methods. srsvs were shown to be associated with 64 of 94 (68%) of these outbreaks, of which 16 (25%) outbreaks occurred at a single location (southend) within the region. twenty-four ... | 1999 | 9854068 |
| identification of further proteolytic cleavage sites in the southampton calicivirus polyprotein by expression of the viral protease in e. coli. | southampton virus (sv) is a human enteric calicivirus with a positive-sense rna genome which encodes a protease as part of a large precursor polyprotein. expression vectors based on prset were constructed carrying the entire 3c-like viral protease (3cpro) sequence together with flanking sequences from a region of the viral genome 3'-distal to the putative helicase-encoding region. expression from these vectors in e. coli resulted in discrete protein products with smaller than expected molecular ... | 1999 | 10073687 |
| outbreak of viral gastroenteritis due to sewage-contaminated drinking water. | in august 1998, a large outbreak of gastroenteritis occurred in a swiss village of 3500 inhabitants whereof more than 50% were affected. a high contamination of drinking water with faecal coliforms revealed a defect in the waste water system. the objective of the present study was to investigate the outbreak in respect of the presence of human pathogenic viruses. drinking water and clinical samples from patients were examined for the presence of 'norwalk-like viruses' (nlvs) and enteroviruses. n ... | 2000 | 10746582 |
| major change in the predominant type of "norwalk-like viruses" in outbreaks of acute nonbacterial gastroenteritis in osaka city, japan, between april 1996 and march 1999. | in osaka city, japan, between april 1996 and march 1999, a total of 350 fecal specimens from 64 outbreaks of acute nonbacterial gastroenteritis were examined to investigate infection by "norwalk-like viruses" (nlvs). by reverse transcription (rt)-pcr, 182 samples (52.0%) from 47 outbreaks (73.4%) were nlv positive. during those three years, the incidence of nlv-associated outbreaks showed seasonality, being higher during january to march (winter to early spring). the ingestion of contaminated oy ... | 2000 | 10878058 |
| polypeptide p41 of a norwalk-like virus is a nucleic acid-independent nucleoside triphosphatase. | southampton virus (shv) is a member of the norwalk-like viruses (nlvs), one of four genera of the family caliciviridae. the genome of shv contains three open reading frames (orfs). orf 1 encodes a polyprotein that is autocatalytically processed into six proteins, one of which is p41. p41 shares sequence motifs with protein 2c of picornaviruses and superfamily 3 helicases. we have expressed p41 of shv in bacteria. purified p41 exhibited nucleoside triphosphate (ntp)-binding and ntp hydrolysis act ... | 2001 | 11160659 |
| molecular detection and sequencing of "norwalk-like viruses" in outbreaks and sporadic cases of gastroenteritis in ireland. | norwalk-like viruses (nlvs) are now established as the most important causative agents of epidemic gastroenteritis worldwide. the overall objective of this study was to determine the molecular epidemiology of irish nlv isolates for the first time by obtaining sequence data from specimens originating from outbreaks and sporadic cases of gastroenteritis. eight samples from sporadic cases of gastroenteritis and nine isolates from separate nlv outbreaks were examined. of the sporadic isolates, six w ... | 2001 | 11536249 |
| viruses that multiply in the gut and cause endemic and epidemic gastroenteritis. | acute infectious diarrhea in young children is a leading cause of morbidity and mortality in developing countries. even in developed countries, infectious enteritis is second only to respiratory infections as a cause of morbidity in early childhood. | 1996 | 15566895 |
| comparison of the polymerase region of small round structured virus strains previously classified in three antigenic types by solid-phase immune electron microscopy. | we have used a reverse transcription-polymerase chain reaction with nested sets of primers to determine the nucleotide sequences of a 166 base pair segment of the rna polymerase region of seven strains of small round structured viruses (srsvs) from the united kingdom. these srsv strains were previously classified by solid-phase immune electron microscopy into three antigenic types--uk2, uk3 and uk4, which are comparable to the prototype strains norwalk virus, hawaii agent, and snow mountain agen ... | 1994 | 7515226 |
| processing of norwalk virus nonstructural proteins by a 3c-like cysteine proteinase. | expression of norwalk virus nonstructural polyprotein precursor in vitro resulted in rapid cotranslational cleavage at specific sites. the cleavage products were similar to those previously identified for southampton virus, a highly related virus. we inactivated the virally encoded proteinase responsible for cleavage of the nonstructural polyprotein by mutation of the putative catalytic cysteine residue, which resulted in production of full-length polyprotein precursor. nv proteinase was express ... | 2003 | 12706072 |
| molecular epidemiology of 'norwalk-like viruses' associated with gastroenteritis outbreaks in new zealand. | outbreaks of gastroenteritis are a major public health problem in new zealand. the introduction of molecular detection methods has now shown that the 'norwalk-like viruses' (nlvs) are the major cause of food and waterborne nonbacterial gastroenteritis. reverse transcription and polymerase chain reaction (rt-pcr) were used to determine the presence of nlvs in faecal specimens from 83 nonbacterial gastroenteritis outbreaks occurring in new zealand between august 1995 and july 1999. further charact ... | 2001 | 11285570 |
| the seroepidemiology of genogroup 1 and genogroup 2 norwalk-like viruses in italy. | southampton virus (sv) and lordsdale viruses (lv) are small round structured viruses characterised recently and belong to two separate genogroups. the capsid genes of these viruses were expressed in insect cells using recombinant baculoviruses. both sv (genogroup 1) and lv (genogroup 2) capsid proteins self-assembled to form virus-like particles (vlps). the vlps were used in a standard enzyme-linked immunosorbent assay (elisa) to screen for antibodies to sv and lv in 1,729 age-stratified human s ... | 1999 | 10223553 |
| reverse transcription-polymerase chain reaction detection and sequence analysis of small round-structured viruses in japan. | between 1985 and 1995, mass outbreaks of acute gastroenteritis caused by small round-structured virus (srsv), occurred in eight prefectures in japan. fecal samples from 59 patients ill during these outbreaks were recently examined in our laboratory by electron microscopy (em) and by reverse transcription-polymerase chain reaction (rt-pcr). for rt-pcr, we prepared two sets of primers, a set corresponding to the polymerase region of open reading frame 1 (orf-1) and a set corresponding to the capsi ... | 1996 | 9015124 |
| characterization of a variant strain of norwalk virus from a food-borne outbreak of gastroenteritis on a cruise ship in hawaii. | a gastroenteritis outbreak affecting at least 217 (41%) of 527 passengers on a cruise ship was caused by a variant strain of norwalk virus (nv) that is related to but distinct from the prototype nv strain. consumption of fresh-cut fruit served at two buffets was significantly associated with illness (p < or = 0.01), and a significant dose-response relationship was evident between illness and the number of various fresh-cut fruit items eaten. seven (58%) of 12 paired serum specimens from ill pers ... | 1994 | 8027335 |