travelers' diarrhea: microbiologic bases for prevention and treatment.the microbiology of travelers' diarrhea has become reasonably well defined, although new bacterial agents are probably yet to be described. the most common etiologic agent, enterotoxigenic escherichia coli (etec), has been studied extensively and, because of the importance of this etiology, strategies for prevention and treatment of etec diarrhea with antimicrobial agents have been devised. the prevention of travelers' diarrhea by immunization will, to a large extent, depend on the development o ...19902406857
epidemiology of travelers' diarrhea and relative importance of various pathogens.each year 12 million persons travel from an industrialized country to a developing country in the tropics or subtropics. these travelers experience a high rate of diarrhea caused by a wide variety of enteric pathogens acquired by ingestion of contaminated food or water. one or more pathogens can be found in the stool of a majority of ill individuals. enterotoxigenic escherichia coli generally are the most frequently identified pathogens, having been found in a median of 42% of travelers' diarrhe ...19902406860
comparative studies on three isolates of breda virus of calves.three isolates of breda virus of calves were compared morphologically and antigenically. the isolates demonstrated similar morphology and shared common antigens, as determined by enzyme-linked immunosorbent assay and immunoelectron microscopy. on the basis of results of the hemagglutination-inhibition test, enzyme-linked immunosorbent assay, and immunoelectron microscopy, the 3 isolates were further subdivided into 2 serotypes: serotype 1 (breda virus 1) represented by the iowa isolate 1; and se ...19852408519
[virology of rotaviruses and the epidemiology of diarrhea caused by rotaviruses]. 19852408634
the use of polylysine during negative staining of viral suspensions.the use of 0.1% aqueous solution of polylysine (poly-l-lysine) is proposed as a prior step to negative staining of viral or particle suspensions. particles spread better on films precoated with polylysine than with other substances used for the same purpose. this applies particularly to samples from sucrose or cscl gradients. the use of negative contrast substances is discussed.19852409100
transitional diarrhoea in newborn infants.a self-limited acute fluid diarrhoea was seen in 80 of 3550 (2.2%) live-born infants not kept in a nursery in this hospital. rotavirus and enteropathogenic serotypes of e. coli were detected with equal frequency with and without diarrhoea. it is suggested that this self-limited episode of diarrhoea occurring soon after birth is not necessarily due to rotavirus infection but could also be due to failure of adaptation to enteral feeding and microbial colonization during this transitional period.19852409891
vertical transmission of enteric pathogens at determine how frequently mothers infect their infants with enteric pathogens at birth, stools were collected from 75 thai mothers immediately before delivery and from their infants 24-48 h later. enteropathogenic escherichia coli (epec) were isolated from 25 of the 75 mothers just prior to delivery (32%), enteroviruses from six (8%), enterotoxigenic e. coli from five (7%), and shigella, salmonella and vibrio parahaemolyticus each from one (1%). epec serotype 0128:k67 was isolated from one mot ...19852409892
enteropathogenic escherichia coli (epec) and enterotoxigenic (etec) related diarrhoeal disease in a neonatal an outbreak of summer diarrhoea in the neonatal unit, king edward viii hospital, durban, 25 (69%) of the 36 infants had organisms demonstrated in their stools. four (11%) had epec alone, six (17%) etec alone, six (17%) epec plus rotavirus and nine (25%) all three organisms. eleven (30%) infants had no organisms in their stools. rotavirus alone was not present in any of the stools. seven infants had septicaemia. the overall mortality was 22% and 62.5% of the deaths occurred in low birthweight ...19852409893
epidemiological aspects of rotavirus infection in young gambian children.rotavirus gastro-enteritis in young gambian children has its maximum impact on infants after the age of one month, in whom it produces short, well-defined annual winter epidemics with clinical dehydration in up to 18% of those infected. sporadic infection was observed in neonates who were often asymptomatic, throughout one year but not in the subsequent year. in two consecutive years studied there was a major change from subgroup i, serotype 2 to subgroup ii, serotypes 1 and 3. this could have c ...19852409894
sequence of the serotype-specific glycoprotein of the human rotavirus wa strain and comparison with other human rotavirus serotypes.complementary dna was synthesized from the double-stranded rna of the wa strain of human rotavirus and inserted into the bacterial plasmid pbr322. clones which contained the gene that codes for the viral glycoprotein (vp7) were identified and the nucleotide sequence was determined. the gene was 1062 base pairs in length with an open reading frame which coded for 326 amino acids. two potential glycosylation sites were found as well as two hydrophobic regions at the n-terminus of the polypeptide. ...19852412362
characteristics of an sa 11 rotavirus variant differing in the outer capsid glycoprotein.the ease with which variants of rotaviruses arise has been further illustrated by the isolation of a variant of simian rotavirus sa 11 differing in the major outer capsid glycoprotein vp7. the difference in mol.wt. between vp7 of the variant (sta virus) and sa 11 virus was 3 x 10(3), with this polypeptide of sta virus still retaining the mannose-rich carbohydrate moiety. limited proteolytic analysis using staphylococcus aureus v.8 protease and trypsin also showed a difference in structure betwee ...19852412538
effect of mutation in immunodominant neutralization epitopes on the antigenicity of rotavirus sa-11.exposure of rotavirus sa-11 to polyclonal neutralizing antibody from hyperimmunized guinea-pigs permitted selection of variants which were poorly neutralized by antisera against the parental virus. in one-way cross-neutralization experiments, at least 22 of 24 plaque-purified variants could be classified as belonging to a serotype different from that of the parent. most antisera generated against the variants, however, readily neutralized the parental virus. this indicates that immunodominant ne ...19852414396
asymptomatic rotavirus infection in nigerian day-care hundred and sixteen stool specimens were collected from five day-care centres in benin city, nigeria, one each from children aged 6-48 months who were free from diarrhoea or any other acute illness. the elisa method showed that 17.2% of the children had rotavirus in their stools. no rotavirus could be detected in the 19 children aged 6-12 months. the incidence of asymptomatic excretors in girls (19.1%) was slightly higher than in boys (15.9%), although this difference was not significant. ro ...19852415057
immunogenicity of a bovine rotavirus glycoprotein fragment.previous experiments demonstrated that an antigenic site responsible for virus neutralization and cell attachment was located on a 14,000-molecular-weight fragment of the major bovine rotavirus (brv) glycoprotein (m. sabara, j. e. gilchrist, g. r. hudson, and l. a. babiuk, j. virol. 53:58-66, 1985). however, it was necessary to investigate whether this fragment also had the ability to induce the production of neutralizing antibodies. upon immunization of mice, the bovine serum albumin-conjugated ...19852415712
rotavirus antigens.the rotaviruses are important medical and veterinary pathogens that cause acute diarrheal disease in children and in the young of most mammalian and avian species. the successful development of a rotavirus vaccine should significantly reduce worldwide infant morbidity and mortality and economic losses and increase food-production. recent successes in the cultivation and characterization of rotavirus strains from humans and animals have led to a better understanding of the major antigens of these ...19852416200
specific labelling of human rotaviruses and adenoviruses with gold-igg complexes.human rotaviruses and adenoviruses were specifically labelled by an indirect immuno gold staining technique for electron microscopy. rabbit antisera against human rota- and adenoviruses were used as the primary antibody and goat anti-rabbit igg-gold complexes as secondary antibody. optimal conditions for the procedure were established by testing serial dilutions of the antisera. precoating of electron microscopy grids with bovine rotavirus antibody decreased nonspecific background staining and a ...19852416768
nucleotide sequence of the structural glycoprotein vp7 gene of nebraska calf diarrhea virus rotavirus: comparison with homologous genes from four strains of human and animal rotaviruses.a full-size cloned cdna copy of the rotavirus gene encoding the structural neutralization glycoprotein (vp7) of nebraska calf diarrhea virus (ncdv), a strain recently shown to be effective as a vaccine in children, has been sequenced. comparison of the deduced amino acid sequence of ncdv (serotype 6) vp7 with that of four other rotavirus strains (human wa serotype 1, human hu-5 serotype 2, simian sa-11 serotype 3, and bovine uk serotype 6) indicates that the degree of amino acid homology among v ...19852417410
detection of human rotaviruses with a 'super-short' rna pattern. 19852418623
rna-binding proteins of bovine rotavirus.two major bovine rotavirus proteins have rna-binding activity as shown by an rna overlay-protein blot assay. of the six proteins in purified virions, only one showed rna-binding activity. this 92,000-molecular-weight (92k) protein was present in both single- and double-shelled particles. its rna-binding activity was blocked by preincubation with monospecific antibody to vp2. thus, the 92k rna-binding protein in rotavirus virions is vp2, the second most abundant protein in single-shelled particle ...19862422396
passive protection against rotavirus-induced diarrhea by monoclonal antibodies to surface proteins vp3 and vp7.monoclonal antibodies directed against two rotavirus surface proteins (vp3 and vp7) as well as a rotavirus inner capsid protein (vp6) were tested for their ability to protect suckling mice against virulent rotavirus challenge. monoclonal antibodies to two distinct epitopes of vp7 of simian rotavirus strain rrv neutralized rrv in vitro and passively protected suckling mice against rrv challenge. a monoclonal antibody directed against vp3 of porcine rotavirus strain osu neutralized three distinct ...19862422398
[immunotherapy in virus diseases].the number of effective anti-viral agents is still limited. therefore immunotherapy remains of importance in the treatment of viral infections. immunoglobulins and interferons as well as a variety of immune stimulators or immune modulators are available. the efficacy of such therapy strongly depends on the kind of the virus causing the infection as well as the time of initiation of the treatment. the prophylactic and therapeutic effects of immunoglobulin preparations are well documented, whereas ...19862422548
location of the major antigenic sites involved in rotavirus serotype-specific neutralization.antigenic sites on the rotavirus major outershell glycoprotein were identified by using mutant viruses selected for resistance to neutralizing (serotype-specific) monoclonal antibodies. the glycoprotein genes from these mutants were sequenced to determine the position and nature of the resultant amino acid substitutions in the protein. three regions (a, b, and c) were identified (amino acids 87-96, 145-150, and 211-223, respectively), of which region c appears to be the most important. a mutatio ...19862422651
protective effect of orally administered immunoglobulins against experimental calf diarrhea. 19862423734
genetic reassortment between two human rotaviruses having different serotype and subgroup specificities.two reassortant viruses were selected from a mixed infection of ma104 cells with human rotavirus strains wa (serotype 1-subgroup ii) and hn126 (serotype 2-subgroup i). antigenic characterization and genotype analysis by polyacrylamide gel electrophoresis revealed that they were reassortants with novel antigenic compositions, i.e. serotype 1-subgroup i (c116) and serotype 2-subgroup ii (c15). furthermore one of them, c15, was considered to have a mosaic antigenicity defined by two serotype-specif ...19862426394
derivation of neutralizing monoclonal antibodies to human rotaviruses and evidence that an immunodominant neutralization site is shared between serotypes 1 and 3.neutralizing monoclonal antibodies were derived to human rotaviruses rv-4 (serotype 1), rv-5 (serotype 2), and st-3 (serotype 4). by enzyme immunoassay and fluorescent focus neutralization, eight of the antibodies appeared to be specific for the immunizing serotype, and so have potential as reagents for rotavirus serotyping by enzyme immunoassay. seven of these were shown by western blotting, enzyme immunoassay for antibody additivity, and reaction with rotavirus reassortants, to be directed aga ...19862429439
prevention of calf diarrhea with an immunoglobulin diet in beef herds. 19862431184
antigenic mapping of the surface proteins of rhesus rotavirus.monoclonal antibodies have been produced and used to map the functional topography of the surface proteins of rhesus rotavirus (rrv) that mediate viral neutralization. ten monoclonal antibodies directed to vp7 were studied in neutralization assays and competitive binding studies. a large neutralization domain with several interrelated epitopes on vp7 was apparent. twelve monoclonal antibodies directed to vp3 were used in similar studies and delineated at least 2 distinct neutralization domains o ...19862431540
analysis by plaque reduction neutralization assay of intertypic rotaviruses suggests that gene reassortment occurs in vivo.the sb-1a rotavirus recovered from a diarrheic piglet in the united states is a naturally occurring intertypic rotavirus. when studied by reciprocal neutralization tests, the sb-1a virus was similar, if not identical, to the porcine gottfried virus (serotype 4) and the porcine osu virus (serotype 5). analysis of reassortant viruses prepared from the sb-1a virus and the serotype 2 human ds-1 virus revealed that the antigenic specificity of the outer capsid protein vp3 of sb-1a was shared with the ...19872434522
an equine rotavirus (fi-14 strain) which bears both subgroup i and subgroup ii specificities on its equinine rotavirus fi-14 strain, originally isolated from a diarrheic foal in new york state, was shown to belong to serotype 3 by neutralization assay. in addition, it was found to react with both subgroup i and subgroup ii monoclonal antibodies by enzyme-linked immunosorbent assay (elisa), thus representing the first rotavirus strain to exhibit both subgroup specificities. by using hybridoma technology, we successfully produced monoclonal antibodies directed against the major inner capsid p ...19872435059
cross-reactive neutralization epitopes on vp3 of human rotavirus: analysis with monoclonal antibodies and antigenic variants.we analyzed cross-reactive neutralization epitopes on protein vp3 of human rotavirus (hrv) by the use of neutralizing monoclonal antibodies (n-mabs), which showed a variety of interserotypic reactivity patterns when examined in a neutralization test and an enzyme-linked immunosorbent assay against 15 hrv and 2 animal rv strains. serological study with the six cross-reactive n-mabs revealed antigenic variations in some hrv strains within the same serotype as well as a marked antigenic difference ...19872437322
synthesis of simian rotavirus sa11 double-stranded rna in a cell-free system.a cell-free system was developed to study the replication of simian rotavirus sa11. the components of the system included (i) subviral particles prepared from infected cells to template the synthesis of viral rna and (ii) an mrna-dependent rabbit reticulocyte lysate to support protein synthesis. based upon nuclease-sensitivity, approximately 20% of the rna made in vitro was double-stranded (dsrna) and 80% single-stranded (ssrna). electrophoretic analysis of the rna products on polyacrylamide and ...19862437720
effects of two negative staining methods on the chinese atypical rotavirus.the chinese atypical (group b) rotavirus, previously called the adult diarrhoea rotavirus (adrv), was examined by transmission electron microscopy using either uranyl acetate or potassium phosphotungstate (pta) as negative stains. complete rotavirus particles were seen using uranyl acetate which were indistinguishable morphologically from typical rotaviruses. in the same preparations virus particles with differing degrees of degradation were seen after staining with pta. this effect was not rela ...19872437888
variation in neutralization epitopes of human rotaviruses in relation to genomic rna polymorphism.fecal rotaviruses collected from october 1983 to september 1984 from outpatients and inpatients attending the royal children's hospital, melbourne, australia, with acute gastroenteritis were serotyped by enzyme immunoassay using rotavirus-neutralizing mouse monoclonal antibodies specific for serotypes 1 to 4. application of three different serotype 1-neutralizing antibodies indicated variations in neutralization epitopes between serotype 1 rotaviruses on the major outer capsid glycoprotein, incl ...19872441519
engineering of immunogenic peptides by co-linear synthesis of determinants recognized by b and t cells.the potential of synthetic peptides as vaccines is restricted by their frequent lack of immunogenicity. as with haptens, coupling to a carrier protein is usually required to provide t cell help to anti-peptide antibody-producing b cells. in spite of their short length, a few natural or synthetic peptides are immunogenic: they all include both a determinant recognized by b cells and a proven or putative determinant recognized by t cells. we speculated that it should be possible to induce immunoge ...19872442000
epitope-specific immune responses to rotavirus vaccination.rotavirus gastroenteritis is a leading cause of infant mortality in developing countries and an important cause of morbidity in children under 2 yr of age in the united states. vaccine programs have evaluated animal rotavirus strains that are attenuated in humans but antigenically similar to some human strains. whether a single vaccine strain can elicit protective immunity in humans to rotaviruses of the same or different serotypes is an important question in determining vaccine efficacy. we use ...19872443417
rotavirus isolate wi61 representing a presumptive new human serotype.a virus (strain wi61) representing a presumptive new human serotype was isolated from an 18-month-old child with gastroenteritis admitted to children's hospital of philadelphia in february 1983. the wi61 virus was clearly distinguished by cross-neutralization tests from human rotaviruses of serotypes 1, 2, 3, and 4, human 69m, and representative bovine (ncdv), porcine (osu), and chicken (ch2) rotaviruses. antisera generated in guinea pigs hyperimmunized to wi61 virus displayed a partial cross-re ...19872443534
glycosylation, an important modifier of rotavirus antigenicity.mutants of a non-glycosylated strain of sa 11 rotavirus (clone 28), were selected using a monoclonal antibody directed against the vp 7 protein. these mutants possessed an amino acid substitution at residue 238 of vp 7, whereas mutants of wild type sa 11 selected with the same antibody have previously been shown to contain a substitution at residue 211 (i.e., in the antigenic c region). in both cases the mutations produce new potential glycosylation sites, and these were found to be utilized. th ...19872444193
electron microscopy procedure influences detection of rotaviruses.technical parameters of electron microscope staining procedures (type of stain, ph of stain, and time of staining) influence particle integrity for three groups of rotaviruses. simian rotavirus sa11 (group a), chinese adult diarrhea rotavirus and porcine rotavirus-like agent (group b), and porcine pararotavirus (group c) were tested. all rotavirus strains were quite stable in uranyl acetate and phosphotungstic acid at ph 4.5 and relatively stable in ammonium molybdate. however, staining with pho ...19872444622
aetiology and clinical features of acute childhood diarrhoea in an outpatient clinic in vellore, india.the aetiology of acute diarrhoea was investigated in 245 children less than 3 years old in a paediatric outpatient clinic in southern india. in 55% of the children organisms were found in the stools, and one quarter were infected with multiple organisms. viruses, enteropathogenic e. coli, shigella and campylobacter species accounted for 75% of all isolates. cholera and helminthiasis were rare, and no child had amoebiasis. clinical findings were useful in the diagnosis of shigella and rotavirus i ...19872445263
rotavirus as an important cause of diarrhoea in a hospital for children in dammam, saudi arabia.a major cause of morbidity and mortality among children in developing countries is acute diarrhoea and rotavirus, a reovirus-like agent, is found to be a leading causative agent. we report here the incidence of rotavirus infection among infants and young children with gastro-enteritis treated at the children's hospital in dammam, kingdom of saudi arabia. one hundred and fifty children, aged between 1 and 60 months, suffering from diarrhoeal illness, were selected as the study cohort; another 150 ...19872445264
expression of coronavirus e1 and rotavirus vp10 membrane proteins from synthetic rna.some viruses acquire their envelopes by budding through internal membranes of their host cell. we have expressed the cloned cdna for glycoproteins from two such viruses, the e1 protein of coronavirus, which buds in the golgi region, and vp10 protein of rotavirus, which assembles in the endoplasmic reticulum. messenger rna was prepared from both cdnas by using sp6 polymerase and either translated in vitro or injected into cultured cv1 cells or xenopus oocytes. in cv1 cells, the e1 protein was loc ...19872448319
analysis of serotype-specific neutralization epitopes on vp7 of human rotavirus by the use of neutralizing monoclonal antibodies and antigenic variants.we analysed serotype-specific antigens of human rotavirus (hrv) by the use of neutralizing monoclonal antibodies (n-mabs). the reactivity patterns of 12 serotype-specific n-mabs against 15 hrv strains in a neutralization test revealed great intraserotypic antigenic variation especially those belonging to serotypes 2,3 and 4. on the basis of the protein specificity of the antibodies examined, it was suggested that whereas serotype 2-specific neutralization epitopes were present on both vp3 and vp ...19882448418
polyacrylamide gel electrophoresis and silver staining for detection of rotavirus in stools from diarrheic patients in thailand.detection of rotavirus by polyacrylamide gel electrophoresis in combination with silver staining and by enzyme-linked immunosorbent assay showed 96.7% identical results in tests with 1,304 stool specimens from diarrheic patients. the polyacrylamide gel electrophoresis method can be modified to reduce cost and working time. phenol extraction of stools, however, is essential in maintaining the sensitivity of the method.19882449452
epidemiology of rotavirus in a periurban gambian community.short, well demarcated epidemics of rotavirus diarrhoea were observed during two consecutive cool, dry seasons in the gambia. this seasonal pattern has now been documented for 4 consecutive years. during the 1985/86 epidemic, transmission was intense, with a clinical attack rate for infants of 36%. during this outbreak it was estimated that asymptomatic virus-shedding was two-thirds as common as symptomatic infection. rotavirus diarrhoea was more severe than diarrhoea due to all other causes and ...19872449845
[simple and rapid electrophoretic detection of rotaviral nucleic acid]. 19872450625
enhancement of peptide immunogenicity by linear polymerization.the effect of linear homopolymerization on the immunogenicity of synthetic peptides was studied using either haptenic peptides (representing amino acid sequences 103-115 and 133-147 of bovine rotavirus major protein) or immunogenic peptides td-103-115 and td-133-147 which were constructed by co-linear synthesis of the former peptides and an amino acid sequence representing a determinant recognized by t helper cells (td). it was found that the two haptenic peptides were rendered immunogenic by li ...19882450754
the outer capsid glycoprotein vp7 of simian rotavirus sa11 contains two distinct neutralization neutralizing monoclonal antibodies (mabs) to the rotavirus simian agent 11 were produced. although displaying variable degrees of haemagglutination-inhibiting activity, they were shown by radioimmunoprecipitation and western blot analyses to react with the major outer capsid glycoprotein (vp7). in competition binding assays, mabs defined two distinct vp7 epitopes, which appeared to be close to each other or partially overlapping. in addition, mabs of the two epitope groups enhanced binding ...19882451709
cross-reactive and serotype-specific neutralization epitopes on vp7 of human rotavirus: nucleotide sequence analysis of antigenic mutants selected with monoclonal antibodies.the neutralization epitopes of human and simian rotavirus protein vp7 were studied by producing six neutralizing monoclonal antibodies (n-mabs) and using these n-mabs to select antigenic mutants that resisted neutralization by the n-mabs used for their selection. cross-neutralization tests between the n-mabs and the antibody-selected antigenic mutants identified one cross-reactive and five distinct serotype-specific neutralization epitopes which operationally overlapped one another and constitut ...19882452893
functional and topographical analyses of epitopes on the hemagglutinin (vp4) of the simian rotavirus immunochemical analysis of the hemagglutinin (vp4) of the simian rotavirus sa11 was performed to better understand the structure and function of this molecule. following immunization of mice with double-shelled virus particles and vp4-enriched fractions from cscl gradients, a battery of anti-sa11 hybridomas was generated. a total of 13 clones secreting high levels of anti-vp4 monoclonal antibody (mab) was characterized and compared with two cross-reactive anti-vp4 mabs generated against heter ...19882452900
identification of cross-reactive and serotype 2-specific neutralization epitopes on vp3 of human rotavirus.the group a rotaviruses are composed of at least seven serotypes. serotype specificity is defined mainly by an outer capsid protein, vp7. in contrast, the other surface protein, vp3 (775 amino acids), appears to be associated with both serotype-specific and heterotypic immunity. to identify the cross-reactive and serotype-specific neutralization epitopes on vp3 of human rotavirus, we sequenced the vp3 gene of antigenic mutants resistant to each of seven anti-vp3 neutralizing monoclonal antibodie ...19882453680
comparative sequence analysis of the genomic segment 6 of four rotaviruses each with a different subgroup specificity.the nucleotide sequences of the genes that code for the major inner capsid protein, vp6, of the human rotavirus strain 1076 (subgroup i), porcine rotavirus gottfried (subgroup ii), equine rotavirus strain h-2 (non-i/ii) and equine rotavirus strain fi-14 (both subgroups i and ii) have been determined. the sixth segment positive-stranded rna encodes a protein of 397 amino acids in all strains with the exception of strain h-2 in which it encodes a protein of 399 amino acids. alignment of amino acid ...19882455770
rotavirus and cryptosporidium shedding in dairy calf feces and its relationship to colostrum immune transfer.twenty holstein calves received 2 l of colostrum twice within 12 h after birth; the first feeding occurred within 2 h of parturition. the increase in adsorption efficiency was related to the gamma globulin provided in the first colostrum feeding. absorption efficiency ranged from 2.4 to 46.1%. the number of sheddings of rotavirus and cryptosporidium by the calves during their first 4 wk of life was associated with serum gamma globulin concentration 24 h after birth and absorption efficiency. abs ...19882456319
bacterial, parasitic and viral enteropathogens associated with diarrhoea in saudi a 2-year study of stools from saudi children with gastro-enteritis and from controls, rotavirus was the pathogen most frequently detected, either alone (44.3%) or in combination with other enteropathogens (7%). there were two peaks for rotavirus isolates, one during the cold months and the other during the dry, hot season. salmonella spp. and campylobacter jejuni were the second and third most frequently isolated enteropathogens. enteropathogenic escherichia coli did not contribute significan ...19882456718
gastro-enteritis in australian children: studies on the aetiology of acute diarrhoea.a prospective, year-long study of the microbiology of childhood gastro-enteritis in perth showed that (i) aeromonas-associated diarrhoea was the commonest recognized bacterial cause for acute diarrhoea, especially in summer, (ii) campylobacter infections were the next most common bacterial cause, (iii) rotavirus and parasites were not significant causes of sporadic acute childhood diarrhoea, and (iv) enteric bacterial pathogens and intestinal parasites were often isolated from aboriginal childre ...19882456732
serotypic analysis of vp3 and vp7 neutralization escape mutants of rhesus rotavirus.neutralization escape mutants of simian rotaviruses (rhesus rotavirus and sa11) were tested in hemagglutination inhibition and neutralization assays against hyperimmune and infection sera to determine if mutation in an immunodominant epitope could enable neutralization escape. an sa11 mutant with a new glycosylation site at amino acid 211 of vp7 was shown to escape neutralization by hyperimmune but not infection sera.19882457117
characterization of homotypic and heterotypic vp7 neutralization sites of rhesus rotavirus.the gene 9 nucleotide sequence was determined for rhesus rotavirus and each of 14 viral variants selected for their resistance to neutralizing monoclonal antibodies. each variant contains a single gene 9, vp7, mutation which permits viral growth in the presence of the antibody. variant mutations were identified in two distinct neutralization regions. region a was identified by monoclonal antibodies that are involved in both serotype-specific and serotype cross-reactive neutralization. region c w ...19882457279
[results of a comparative study of two immunoelectron microscopy methods for the diagnosis of rotavirus infection]. 19882457735
identification of a group-reactive epitope of group b rotaviruses recognized by monoclonal antibody and application to the development of a sensitive immunoassay for viral b rotaviruses (gbrs) are fastidious agents which cause enteric disease in humans and a number of other animal species. detailed study of the role of gbrs in human disease has been hampered by the lack of immunoreagents suitable for large-scale studies. we developed a monoclonal antibody which recognizes a group-reactive antigen contained in a number of strains of gbrs. when utilized in conjunction with a hyperimmune guinea pig antiserum to gbr, this monoclonal antibody can be used in an en ...19882460499
prevalence of cryptosporidiosis in dammam and alkhobar, saudi arabia.this report presents results from a 6-month study over the period 16 november 1986 to 15 may 1987 which was designed to investigate the prevalence of cryptosporidiosis in dammam and alkhobar, saudi arabia. a total of 209 stool specimens from children and 112 from adults with diarrhoea were examined. only two (1%) of the children, both aged 2 years, were positive for cryptosporidium spp. giardia lamblia was found in 13 (4%) cases and was found to be the most common protozoan parasite, whereas sal ...19882461154
[development of test systems of immunoenzyme analysis for the rapid diagnosis of rotavirus infection].a test system of enzyme immunoassay (eia) consisting of simian rotavirus sa-11 and rabbit antiserum has been developed for the detection of rotavirus antigen. direct eia was used for tests on stool specimens from 289 children varying in ages from 10 days to 12 years suffering from acute enteric infections and 56 normal children. the antigen was detected in 22.1% and 3.5%, respectively, in patients predominantly in the first 3 days of the disease and most frequently in cases running as gastroente ...19882461616
high-resolution chromatography of nucleic acids on the gen-pak fax column.high-performance liquid chromatography (hplc) on a gen-pak fax column has been used to separate and purify microgram amounts of single- and double-stranded dna and rna molecules. hplc of mixtures of dna restriction fragments showed that fragments within the size range 0.125-23.1 kilobase were easily resolved. supercoiled (form i) plasmid dna molecules were readily separated from single-stranded circular dna of the same length and from various dna conformational isomers including nicked (form ii) ...19882462570
[molecular epidemiology of rotaviruses].group a rotaviruses have been recognized worldwide as the main viral cause of acute infantile gastroenteritis and of diarrhoea of the young of a wide variety of animal species. the molecular epidemiology of rotaviruses has revealed an extensive genomic and antigenic variability of successively occurring or cocirculating human group a rotaviruses. group b rotaviruses have been found to cause outbreaks of acute gastroenteritis among adults in china. the genomic and antigenic diversity of human rot ...19882463221
molecular epidemiology and subgroup determination of bovine group a rotaviruses associated with diarrhea in dairy and beef calves.the genome electropherotyping technique was used to examine group a rotaviral infections of diarrheic calves ranging from 1 to 85 days of age in 2 beef and 27 dairy herds. coelectrophoresis studies demonstrated 38 distinct bovine group a rotavirus genome electropherotypes; all were long genome electropherotypes, and none had extra segments or unusual segment rearrangements. genome electropherotypes in fecal specimens from diarrheic calves previously inoculated orally with a commercial, modified- ...19892463994
[a method of detecting the rotavirus antigen in feces].counter-current immunoelectrophoresis (cciep) has been employed for indication of a rotaviral antigen. 50% feces homogenate in physiologic saline, clarified by centrifugation, has been used in the test, as well as a highly active antiserum of rabbits immunized with calf diarrhea (nebraska strain) rotavirus. the results of parallel studies of 103 feces samples collected from children with acute gastroenteritis, carried out by cciep and electron microscopy, coincided in 84.5% of cases. the authors ...19892467062
rotavirus infection in newborn calves. i. evaluation trials of certain enzymes in faeces.the purpose of this work was to investigate the relationship between rotavirus infection, diagnosed in faeces using the serological test, in calves with diarrhoea and the activity of lysozyme, alpha-amylase, lipase and trypsin in the same material. the faeces were taken from 28 sick and 1 healthy animals, aged from 1 to 5 days, for microbiological and enzymatic examination. no correlation was found between lysozyme activity in faeces and rotavirus infection. similar results were obtained with th ...19892467466
enteropathogens isolated from children with gastro-enteritis at ga-rankuwa hospital, south africa.a prospective 3-year study for enteric pathogens associated with diarrhoea in children was undertaken at ga-rankuwa hospital, south africa. rotavirus was the most commonly isolated pathogen (24%), showing a marked seasonal distribution, with an autumn peak in activity. enterotoxigenic and enteropathogenic escherichia coli were frequently identified, and salmonella, shigella and campylobacter were also isolated. cryptosporidium and giardia lamblia were the most frequently seen parasites. rotaviru ...19882467616
preparation and characterization of monoclonal antibodies to utilizing a strain of cultivable simian rotavirus (sa-11) as an immunizing antigen, we prepared 4 clones of mouse-mouse hybridoma, namely c127, c139, c172, and c214 which secreted monoclonal antibodies against the immunogen itself, sa-11 and also against other group a strains such as wa and s2. western blot analyses revealed that all of these antibodies are directed against vp6, a 42 kda major inner capsid protein of group a rotavirus. competitive experiments suggested that c127, c172 and c21 ...19892469693
[experience in the use of the coagglutination reaction in diagnosing rotavirus infections in children].to improve the etiologic diagnosis of acute intestinal infections in children and to identify a rotaviral infection, a solid-phase coagglutination test for the detection of a rotaviral antigen has been introduced into the complex of diagnostic tests. this method is available and simple, highly sensitive and specific. the authors describe the technique of the test and give their recommendations on how to introduce this test into practice at hospitals for infectious diseases.19892469829
passive protection against rotavirus-induced diarrhea by monoclonal antibodies to the heterotypic neutralization domain of vp7 and the vp8 fragment of vp4.a murine model was used to determine whether neutralizing monoclonal antibodies (mabs) with heterotypic specificity directed to vp7 (mab 57-8) or to the vp8 fragment of vp4 (mab m14) passively protect mice against challenge with various strains of rotavirus. (the gene 4 product, an outer capsid protein, has traditionally been called vp3. it has been proposed, however, that the rotavirus gene 4 product be named vp4. the gene 3 product, a core protein, has been identified recently and named vp3 [m ...19892470774
temporal variation of malaysian rotavirus analysis of rotavirus electropherotypes circulating in kuala lumpur, malaysia, over 7 years showed that all except 1 of the 360 electropherotypes encountered were characteristic of group a rotaviruses. the long electropherotype predominated annually, and there was a rarity of short electropherotypes. extensive genome variability and cocirculation of different electropherotypes were observed annually. a sequential appearance of the predominant electropherotype was observed in all years of the ...19892470775
[a comparison of the efficacy of the passive hemagglutination reaction and the reverse passive hemagglutination reaction for detecting the rotavirus antigen in feces].these two tests have been used for the detection of a rotaviral antigen in feces of patients suffering from gastrointestinal disorders. antibody erythrocytic rotaviral diagnostic agent has been employed in both the tests. a comparative analysis has demonstrated the specificity of both the tests for the indication of a rotavirus and a higher sensitivity of passive hemagglutination.19892470978
molecular determinant of rotavirus neutralization and protection. 19892472045
complete nucleotide sequence of the gene encoding vp4 of a human rotavirus (strain k8) which has unique vp4 neutralization our previous study (k. taniguchi, y. morita, t. urasawa, and s. urasawa, j. virol. 62:2421-2426, 1987) in which the cross-reactive neutralization epitopes on vp4 of human rotaviruses were analyzed, one strain, k8, was found to bear unique vp4 neutralization epitopes. this strain, which belongs to subgroup ii and serotype 1, was not neutralized by any of six anti-vp4 neutralizing monoclonal antibodies which reacted with human rotavirus strains of serotypes 1, 3, and 4 or serotypes 1 through 4. ...19892474677
rotavirus vp7 neutralization epitopes of serotype 3 strains.sequence analysis of the gene encoding the major neutralization glycoprotein (vp7) was performed on 27 human and animal rotavirus strains of serotype 3 in order to examine genetic variation within strains of identical serotype. comparisons of the deduced amino acid sequences of the vp7s showed overall sequence identities of 85% or higher. a higher degree of overall vp7 sequence similarity was observed among strains from the same animal species when compared to strains from different animal speci ...19892474892
follow-up of gambian children for a 1-year period after rotavirus investigate the hypothesis that rotavirus infection in young children can trigger chronic diarrhoeal disease, a group of cases from a documented epidemic of rotavirus and a group of matched controls were followed for a 1-year period after infection. no evidence of excess chronic diarrhoea or vomiting in the group known to have been infected with rotavirus was found.19892475055
comparative studies of the antigenic polypeptide species vp4, vp6, and vp7 of three strains of bovine rotavirus.three bovine rotavirus strains belonging to two distinct serotype groups, serotype 6 (ncdv and b641) and b223, distinct from the other six mammalian rotavirus serotypes but not yet assigned to a serotype group, were compared with each other and with canine rotavirus (k9, serotype 3) by studying the properties of their cognate polypeptide species vp4, vp6, and vp7. the three viruses showed distinct differences in the polyacrylamide gel electrophoretic migration rates of protein species vp4 and vp ...19892476464
animal model of rotavirus infection in rabbits--protection obtained without shedding of viral antigen.a small animal model was developed in order to investigate the pathogenesis and immunology of rotavirus infections and to study the interaction of different virus strains. seronegative rabbits of the breed french lop were used. two rabbit rotavirus strains, belonging to the same serotype, were used: 82/311 f and r-2, both isolated during diarrhoeal outbreaks in commercial rabbitries. the animals were inoculated orally. the viral shedding and the serological response was monitored by elisa. initi ...19892479363
seroepidemiology of adult diarrhea rotavirus in china, 1977 to 1982, large outbreaks of diarrhea that were caused by group b adult diarrhea rotavirus (adrv) occurred throughout the people's republic of china. until 1982, group b rotavirus had never been associated with disease in humans. to determine whether adrv was a new virus introduced in 1982 or had been present before that time, we examined antibody titers of adrv in gamma globulin (pooled immunoglobulin) pools that were prepared during 1977 to 1987 in four cities in the people's republic of china ...19892479654
nonreactivity of american avian group a rotaviruses with subgroup-specific monoclonal antibodies.nine group a rotavirus isolates recovered from commercially reared poultry in the united states did not react with subgroup 1 (255/60) or subgroup 2 (631/9) specific monoclonal antibodies in an enzyme-linked immunosorbent assay.19892480363
vp4 protein of porcine rotavirus strain osu expressed by a baculovirus recombinant induces neutralizing antibodies.the complete vp4 gene of porcine rotavirus strain osu has been inserted into a baculovirus expression vector under the control of the polyhedrin promoter. the vp4 outer capsid protein, which is a major neutralization antigen in rotavirus, was expressed in high yield in spodoptera frugiperda cells. reactivity with polyclonal and monoclonal antibodies suggested that neutralizing epitopes were functionally unaltered on the expressed vp4. the vp4 produced in this system also induced antibodies in gu ...19892480689
[use of the diffuse precipitation reaction for detecting anti-rotavirus antibodies in children].antirotaviral antibodies have been detected by the diffuse precipitation test in 16% of 355 patients with acute intestinal infections aged 1 month to 14 years; specific coproantibodies have been detected in 1.4% of 138 patients. the authors emphasize the specificity and simplicity, though a lower sensitivity of the diffuse precipitation vs. the neutralization test.19892481143
synthesis in escherichia coli of the major glycoprotein of human rotavirus: analysis of the antigenic regions.various regions of the gene encoding the major neutralization antigen, vp7, of human rotavirus have been expressed in escherichia coli, as n-terminal fusions to beta-galactosidase under the control of the lac promoter. we have determined that the fusion products of two clones containing regions ab (aa 69-158) and abc (aa 69-319) were antigenic, reacting with antibodies raised against whole virus. when guinea pigs were immunized with fusion protein purified by monoclonal antibody affinity columns ...19892481606
aetiological factors of infantile diarrhoea: a community-based study.a community-based study was undertaken to compare the organisms responsible for diarrhoea in children living in formal housing with indoor water supply and sanitation with those from a deprived environment. the role of "home remedies" was also assessed. among 373 children with diarrhoea, rotavirus was detected in 15% (in 371 symptom-free controls, 9%), and proved to be the single most common causative agent. bacterial pathogens were found in 20% of patients, with enteropathogenic escherichia col ...19892482008
the in vitro antiviral activity of isoprinosine on simian rotavirus (sa-11).1. the antiviral effect of isoprinosine on simian rotavirus (sa-11) replication was studied using ma-104 cell cultures from rhesus monkey fetal kidney. 2. isoprinosine (n,n-dimethylamino-2-propanol-p-acetamidobenzoate in association with inosine) added after viral infection (therapeutic test) inhibited viral replication by more than 90%. in these experiments, the drug was added to the medium and replaced daily at concentrations varying from 62.5 micrograms/ml to 1 mg/ml. viral inhibition activit ...19892483980
[the fate of pathogens in waste-waters].a large variety of pathogenic organisms capable of transmission by the faecal-oral route may be found in wastewaters. among the bacteria salmonella, shigella, vibrio cholerae, yersinia and campylobacter are the important agents of concern. also the human enteric viruses (poliovirus, coxsackievirus, echovirus, hepatitis a virus, rotavirus) have been shown to be present in domestic waste and may not be completely removed by conventional sewage treatment processes, including chlorination. discharge ...19892484470
[old and new pathologies proposed by epidemiology].the results of a study made in the areas of central italy on a random community on the significant presence of cases with seroantibodies against campylobacter, yersinia, legionella pneumophila, francisella tularensis and rotavirus confirm the hypothesis on the presence in the territory of microorganisms responsible. these positivities in man are not only single but also contemporaneous for at least two microorganisms. hence the hypothesis of the presence in the environment (animals, soil, surfac ...19892490401
[epidemiological study of diarrhea in children 0-5 yr of age].the authors use an investigation carried out at pikine social paediatric institute on children consulting for diarrhoea to underline the epidemiological factors of this affliction in dakar suburbs: the average age of the children is 14 months; almost half the children came from families with low or irregular incomes; coprologic examination showed parasitic germs in 26.7% of the cases, rotavirus in 24.4%, and bacteria in 17.6%.19892491378
the interferon sensitivity of selected porcine viruses.the objective of this study was to compare the sensitivity of 11 porcine viruses to the antiviral effects of porcine interferon-alpha in serum from piglets which had been infected 19 h previously with transmissible gastroenteritis virus, and of porcine interferon-beta prepared in pk-15 cells by induction with polyinosinic:polycytidylic acid, in yield reduction assays in pig kidney cells which were treated with interferon before virus challenge, and both before and after virus challenge. the most ...19892492445
acute gastroenteritis in children--aetiology and comparison of two modes of treatment.287 patients with acute gastroenteritis were studied. rotavirus accounted for 29.7% and bacterial aetiology for 9.3% of the cases. in the early infant age group (0-6 months), bacterial aetiology (28.8%) was commoner than rotavirus aetiology (7.7%). in the older age groups, rotavirus was more common than bacteria as a cause for gastroenteritis.19892496637
intestinal permeability changes in acute gastroenteritis: effects of clinical factors and nutritional management.the effects of early home management of acute diarrhea followed by rapid in-hospital realimentation on intestinal permeability were studied in 41 children aged 3-25 months with acute gastroenteritis (73% rotavirus). after oral rehydration, a 100 ml oral load containing 4 g of lactulose and 0.8 g of mannitol was administered, and an aliquot of urine excreted in the subsequent 5 h was analyzed with gas-liquid chromatography. the mean lactulose/mannitol recovery ratio was significantly higher than ...19892498498
[electron microscopic virus detection in fecal samples from swine with enteric diseases between 1981 and 1987].results of electron microscopical studies of 517 fecal samples from diarrhoeic pigs out of the years 1981 and 1987 were reported. coronavirus was found in 26.3%, rotavirus in 4.3%, parvovirus in 2.1%, coronavirus like particles in 2.9% and picornavirus like particles in 2.3% of the samples. in some cases (2.3%) double infections could be detected occurring as well between corona- and rotavirus, parvovirus or picornavirus like particles as between rotavirus and parvovirus and picornavirus like pa ...19892503347
[electron microscopic detection rate of enteral viruses in diarrhea of dogs, cats, calves, swine and foals in the year 1988--electron microscopic study results].during 1988 fecal and gut samples of 641 dogs, 198 cats, 576 calves, 108 piglets and 64 foals with diarrhoea were investigated for virus infections by electron microscopy. in samples of dogs and cats parvovirus was detected at a proportion of 21.9% and 16.7%, respectively; rotavirus alone or together with coronavirus was found only in 0.3-1.5% of the specimens. in samples of calves rotavirus, as well as coronavirus dominated with a detection rate amounting to 17.4% and 26.6% respectively (includ ...19892513799
electron microscopy of stool-shed viruses: retention of characteristic morphologies after long-term storage at ultralow of stool specimens at -70 degrees c has been reported to destroy the characteristic morphology of calicivirus. to determine if other stool-shed viruses are similarly affected, stool specimens previously examined by electron microscopy and observed to contain virus particles were reexamined after 6-10 years of storage at -70 degrees c to -85 degrees c. the stools contained virus particles of different morphological types, including astrovirus, small round structured virus, adenovirus, and ...19892515253
[comparative study of nitrogen, lipids and energy loss through the feces in children dehydrated by acute diarrhea due to rotavirus and other agents].with a view to observing if gastroenteritis to rotavirus produced greater carbohydrate malabsorption, we studied 94 male infants, between three and thirty six months of age, with acute diarrhea and dehydration. the metabolic study included the analysis of every intake and excretion during the first 24 hours of oral rehydration and realimentation. thirty two infants had rotavirus as the single etiological agent, but in numbers it could only be compared to 35 patients in whom we were unable to est ...19892518016
[modular diet and parenteral support in persistent diarrhea].eleven infants with protracted diarrhea were treated with modular diet and short-term parenteral nutrition. mean age at admission was 3.7 months with males predominating. enteropathogenic e. coli, classic serotypes, were isolated from 7 patients and rotavirus from one. a child with combined, severe immunodeficiency died. milk protein intolerance was diagnosed in another patient. balance studies and peroral biopsies were performed. malnutrition was more frequent and hospital stay was longer in th ...19892518464
evaluation of three oral rehydration solutions designed for use in developed hundred and sixteen children (less than 2 years old) admitted to a london hospital with acute gastroenteritis were randomized to receive either an oral rehydration solution (ors) with low sodium and high glucose concentration (na+ 35, glucose 200 mmol/l), an ors with a high sodium but low glucose concentration (na+ 60, glucose 111 mmol/l), or an ors containing glycine and a glucose polymer (na+ 50, glucose 50, glycine 50 mmol/l). clinical, biochemical and haematological features of the three ...19892520619
[sporadic rotavirus gastroenteritis in adults]. 19892532414
human calicivirus-associated diarrhea in children attending day care centers.we investigated human calicivirus (hcv)-associated diarrhea in children attending day care centers by using stool specimens collected in 1981-1983. we used a screening enzyme-linked immunosorbent assay (elisa) derived from reagents prepared against the sapporo strain of hcv and confirmed positive results with a blocking elisa and immunosorbent electron microscopy. hcv was detected in 11 (2.9%) of 375 diarrheal stools and in none of 86 stools from asymptomatic contacts. this incidence rate was ha ...19892535867
effects of antibody to rotavirus on protection of adults challenged with a human rotavirus.effects of preinoculation rotavirus antibody titers on the probability of infection and illness were evaluated in adults challenged orally with different doses of a virulent human rotavirus (cjn strain). preinoculation titers considered were serum neutralizing antibody, serum rotavirus iga, serum rotavirus igg, jejunal neutralizing antibody, jejunal rotavirus iga, and stool rotavirus iga. doses of virus of either 9 x 10(1) or 9 x 10(3) focus-forming units were administered to 19 subjects each. t ...19892535868
discrepant rotavirus results in two laboratories using the same enzyme immunoassay.rotavirus testing was performed on 66 stool samples in two separate laboratories using the same enzyme immunoassay. sixteen of 46 of the positive results reported by the reference laboratory were negative in the hospital laboratory. in addition, rna gel electrophoresis had negative results in the 16 discrepant samples. this indicates the need to repeat or confirm positive results.19892535915
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