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Lamson DM, Ramani R, Kleabonas M, Metcalfe M, Humphrey C, St George K. An unusual case of influenza-like illness after yellow fever vaccination. J Clin Virol 2014; 60:67-9. [PMID: 24594082 PMCID: PMC7128991 DOI: 10.1016/j.jcv.2014.01.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 01/23/2014] [Accepted: 01/24/2014] [Indexed: 10/25/2022]
Abstract
Yellow fever (YF) is an important public health concern in areas where the disease is endemic. For more than 60 years a highly effective live attenuated vaccine has been available, its widespread use resulting in a dramatic decrease in the number of cases. On rare occasions, YF vaccine can cause mild to severe disease and rare adverse vaccine-associated events have been reported. Additionally, an average viremia of 3-5 days after administration of the YF vaccine has been published. Here we present a case where YF vaccine was isolated in cell culture from a respiratory swab collected from a patient presenting with influenza-like illness. To the best of our knowledge, this is the first report finding replicating YF vaccine in the respiratory sample of a post inoculated individual.
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Affiliation(s)
- Daryl M Lamson
- Wadsworth Center, New York State Department of Health, Albany, NY, USA.
| | - Rama Ramani
- Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Matthew Kleabonas
- Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Maureen Metcalfe
- Infectious Diseases Pathology Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Charles Humphrey
- Infectious Diseases Pathology Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Kirsten St George
- Wadsworth Center, New York State Department of Health, Albany, NY, USA
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Castrignano SB, Nagasse-Sugahara TK, Kisielius JJ, Ueda-Ito M, Brandão PE, Curti SP. Two novel circo-like viruses detected in human feces: complete genome sequencing and electron microscopy analysis. Virus Res 2013; 178:364-73. [PMID: 24055464 DOI: 10.1016/j.virusres.2013.09.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 09/08/2013] [Accepted: 09/10/2013] [Indexed: 11/26/2022]
Abstract
The application of viral metagenomic techniques and a series of PCRs in a human fecal sample enabled the detection of two novel circular unisense DNA viral genomes with 92% nucleotide similarity. The viruses were tentatively named circo-like virus-Brazil (CLV-BR) strains hs1 and hs2 and have genome lengths of 2526 and 2533 nucleotides, respectively. Four major open reading frames (ORFs) were identified in each of the genomes, and differences between the two genomes were primarily observed in ORF 2. Only ORF 3 showed significant amino acid similarities to a putative rolling circle replication initiator protein (Rep), although with low identity (36%). Our phylogenetic analysis, based on the Rep protein, demonstrated that the CLV-BRs do not cluster with members of the Circoviridae, Nanoviridae or Geminiviridae families and are more closely related to circo-like genomes previously identified in reclaimed water and feces of a wild rodent and of a bat. The CLV-BRs are members of a putative new family of circular Rep-encoding ssDNA viruses. Electron microscopy revealed icosahedral (~23 nm) structures, likely reflecting the novel viruses, and rod-shaped viral particles (~65-460 × 21 × 10 nm in length, diameter, and axial canal, respectively). Circo-like viruses have been detected in stool samples from humans and other mammals (bats, rodents, chimpanzees and bovines), cerebrospinal fluid and sera from humans, as well as samples from many other sources, e.g., insects, meat and the environment. Further studies are needed to classify all novel circular DNA viruses and elucidate their hosts, pathogenicity and evolutionary history.
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Affiliation(s)
- Silvana Beres Castrignano
- Department of Respiratory Diseases, Adolfo Lutz Institute, Av. Dr. Arnaldo, 355, CEP 01246-902, São Paulo, SP, Brazil.
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Kimura AC, Mead P, Walsh B, Alfano E, Gray SK, Durso L, Humphrey C, Monroe SS, Visvesvera G, Puhr N, Shieh WJ, Eberhard M, Hoekstra RM, Mintz ED. A Large Outbreak of Brainerd Diarrhea Associated with a Restaurant in the Red River Valley, Texas. Clin Infect Dis 2006; 43:55-61. [PMID: 16758418 DOI: 10.1086/504805] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2005] [Accepted: 01/12/2006] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND In June 1996, an outbreak of chronic diarrhea was reported to the Texas Department of Health (Austin). METHODS We initiated active case finding, performed 2 case-control studies, and conducted an extensive laboratory and environmental investigation. RESULTS We identified 114 persons with diarrhea that lasted > or = 4 weeks. Symptoms among 102 patients who were studied included urgency (87%), fatigue (86%), fecal incontinence (74%), and weight loss (73%); the median maximum 24-h stool frequency was 15 stools. Diarrhea persisted for > 6 months in 87% and for > 1 year in 70% of patients who were observed. Fifty-one (89%) of 57 ill persons had eaten at a particular restaurant within 4 weeks before onset, compared with 8 (14%) of 59 matched control subjects (matched odds ratio [OR], undefined; 95% confidence interval [CI], 11.2-infinity). At the restaurant, patients were more likely than their unaffected dining companions to have drunk tap water (OR, 2.8; 95% CI, 1.0-9.9) and to have eaten several specific food items, and they were less likely to have drunk iced tea made from boiled water and store-bought ice (OR, 0.3; 95% CI, 0.05-1.0). A multivariable model that included consumption of tap water and salad bar tomatoes best fit the data. The restaurant had multiple sanitary and plumbing deficiencies. Extensive laboratory and environmental testing for bacterial, parasitic, mycotic, and viral agents did not identify an etiologic agent. CONCLUSIONS The clinical, laboratory, and epidemiologic findings are consistent with those of previous outbreaks of Brainerd diarrhea. To our knowledge, this is the largest reported outbreak of Brainerd diarrhea associated with a restaurant.
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Affiliation(s)
- Akiko C Kimura
- Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
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Biel SS, Gelderblom HR. Diagnostic electron microscopy is still a timely and rewarding method. J Clin Virol 1999; 13:105-19. [PMID: 10405897 PMCID: PMC7128371 DOI: 10.1016/s1386-6532(99)00027-x] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/1999] [Accepted: 03/09/1999] [Indexed: 12/02/2022]
Abstract
BACKGROUND Parallel to its technical development starting in the 1930s, electron microscopy (EM) became an important tool in basic and clinical virology. First utilized in the rapid diagnosis of smallpox, it developed to a diagnostic routine in the early 1960s using the negative staining technique. EM was applied to infected cell-cultures and also to 'dirty' specimens including urine, feces, vesicle fluid, liquor. With the implementation of molecular biological and genetic techniques, the use of diagnostic EM decreased. OBJECTIVES (1) To give a perspective on future indications and possible uses by discussing the past and the present of diagnostic EM, (2) To describe the system of External Quality Assessment on EM virus diagnosis (EQA-EMV) established in 1994 by our laboratory and its achievements. STUDY DESIGN EQA-EMV is run to evaluate, to confirm and to improve the quality of diagnostic EM. Two different types of specimen are sent out: (1) prepared grids to assess and train the diagnostic skills of the participants, (2) stabilized virus particle suspensions to assess preparation efficiency. RESULTS Diagnostic EM differs from other diagnostic tests in its rapidity and its undirected 'open view'. To emphasize these advantages, the indications for diagnostic EM are discussed, fundamental for a continuing future adaptation. Besides appropriate techniques, quality control measures are required to achieve and keep high diagnostic standards. The results from 6 years of EQA-EMV are presented. CONCLUSIONS In the history of diagnostic EM in virology, a change in use has been seen. Starting in the 1990s and coincident with the broad introduction of 'modern' diagnostic techniques, the number of EM diagnostic labs has decreased considerably--in spite of the obvious advantages of this technique. To guarantee the continuing performance of diagnostic EM in the future. EQA runs have to be performed as with other techniques in the diagnostic armament. The growing number of participants and participating countries indicates an interest in as well as a need for this program.
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Key Words
- electron microscopy
- rapid viral diagnosis
- quality control
- external quality assessment
- em, electron microscope, electron microscopy
- eqa, external quality assessment scheme
- eqa-emv, external quality assessment scheme on em virus diagnosis
- ictv, international committee on the taxonomy of viruses
- iem, immune electron microscopy
- nat, nucleic acid amplification techniques
- spiem, solid phase immune electron microscopy
- srnsv, small round non-structured viruses
- srsv, small round structured viruses
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Affiliation(s)
- Stefan S. Biel
- Robert Koch-Institut, Konsiliarlaboratorium für elektronenmikroskopische Erregerdiagnostik, Nordufer 20, D-13353 Berlin, Germany
| | - Hans R. Gelderblom
- Robert Koch-Institut, Konsiliarlaboratorium für elektronenmikroskopische Erregerdiagnostik, Nordufer 20, D-13353 Berlin, Germany
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Noel JS, Liu BL, Humphrey CD, Rodriguez EM, Lambden PR, Clarke IN, Dwyer DM, Ando T, Glass RI, Monroe SS. Parkville virus: A novel genetic variant of human calicivirus in the Sapporo virus clade, associated with an outbreak of gastroenteritis in adults. J Med Virol 1997. [DOI: 10.1002/(sici)1096-9071(199706)52:2<173::aid-jmv10>3.0.co;2-m] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Leite JP, Ando T, Noel JS, Jiang B, Humphrey CD, Lew JF, Green KY, Glass RI, Monroe SS. Characterization of Toronto virus capsid protein expressed in baculovirus. Arch Virol 1996; 141:865-75. [PMID: 8678832 DOI: 10.1007/bf01718161] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Toronto virus (TV), previously called "minireovirus", a human calicivirus classified as genogroup 2 and phylogenetic type P2-A, was originally described in association with diarrhea in children. The second open reading frame, encoding the capsid protein of TV24, was expressed in a baculovirus recombinant. The recombinant baculovirus produced a protein (rTV) with an apparent molecular mass of 58 kDa that self-assembled into virus-like particles approximately 30 nm in diameter with a density of 1.29 g/ml. Antigenic and immunogenic characteristics of these particles were determined by protein immunoblot, immunoprecipitation, and enzyme immunoassay. Seroconversion to the rTV protein was detected in 6 of 8 (75%) patients from a recent outbreak of gastroenteritis associated with a virus of similar phylogenetic type. These results confirm and extend the previous reports of the expression of the Norwalk and Mexico virus capsid proteins.
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Affiliation(s)
- J P Leite
- Viral Gastroenteritis Section, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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Purdy MA, Carson D, McCaustland KA, Bradley DW, Beach MJ, Krawczynski K. Viral specificity of hepatitis E virus antigens identified by fluorescent antibody assay using recombinant HEV proteins. J Med Virol 1994; 44:212-4. [PMID: 7531755 DOI: 10.1002/jmv.1890440217] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A fluorescent antibody (FA) assay for hepatitis E virus antigen (HEVAg) in infected liver tissue was used to confirm the presence of virus-specific antigens in hepatocytes during the course of infection. With the cloning of the HEV genome it is now possible to determine which viral antigens are recognized by this FA assay. Recombinant HEV proteins covering the carboxyl half of HEV open reading frame 2 (ORF2) were used in this study to demonstrate that some of the most immunoreactive virus-specific antigens detected by FA are contained within this region of ORF2 (nucleotides 6169-7126).
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Affiliation(s)
- M A Purdy
- Hepatitis Branch, Centers for Disease Control and Prevention, Atlanta, Georgia 30333
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Herwaldt BL, Lew JF, Moe CL, Lewis DC, Humphrey CD, Monroe SS, Pon EW, Glass RI. Characterization of a variant strain of Norwalk virus from a food-borne outbreak of gastroenteritis on a cruise ship in Hawaii. J Clin Microbiol 1994; 32:861-6. [PMID: 8027335 PMCID: PMC263153 DOI: 10.1128/jcm.32.4.861-866.1994] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
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 persons demonstrated at least fourfold rises in antibody response to recombinant NV capsid antigen. A 32-nm small round-structured virus was visualized by electron microscopy in 4 (29%) of 14 fecal specimens, but none of the 8 specimens that were examined by an enzyme immunoassay for NV antigen demonstrated antigen. Four (40%) of 10 fecal specimens were positive by reverse transcriptase-PCR by using primer pairs selected from the polymerase region of NV. In a 145-bp region, the PCR product shared only 72% nucleotide sequence identity with the reference NV strain and 77% nucleotide sequence identity with Southampton virus but shared 95% nucleotide sequence identity with UK2 virus, a United Kingdom reference virus strain. In addition, the outbreak virus was serotyped as UK2 virus by solid-phase immune electron microscopy. The genetic and antigenic divergence of the outbreak strain from the reference NV strain highlights the need for more broadly reactive diagnostic assays and for improved understanding of the relatedness of the NV group of agents.
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Affiliation(s)
- B L Herwaldt
- Division of Parasitic Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333
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Ticehurst J, Popkin TJ, Bryan JP, Innis BL, Duncan JF, Ahmed A, Iqbal M, Malik I, Kapikian AZ, Legters LJ. Association of hepatitis E virus with an outbreak of hepatitis in Pakistan: serologic responses and pattern of virus excretion. J Med Virol 1992; 36:84-92. [PMID: 1583470 DOI: 10.1002/jmv.1890360205] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Hepatitis E virus (HEV), a positive-strand RNA agent, has been associated with enterically transmitted non-A, non-B hepatitis in Asia, Africa, and Mexico. To evaluate the role of HEV in an outbreak of hepatitis in Pakistan, we used immune electron microscopy to detect 1) antibody to HEV, for evidence of infection, and 2) virus, to determine the pattern of HEV excretion. Paired sera from 2 patients were assayed for antibody by using reference HEV: one seroconverted, an atypical finding for HEV infections; the other had high levels of anti-HEV in both sera. Virus particles with the size (29 x 31 nm) and morphology of HEV were detected in feces from 10 of 85 patients and serologically identified as HEV by using reference antibodies from an HEV-infected chimpanzee. One of these HEV-containing specimens was collected 9 days before the onset of jaundice; it was among feces from 38 outpatients with nonspecific symptoms and biochemical hepatitis, 12 of whom subsequently developed jaundice. The other 9 feces with HEV were among 36 collected within 7 days of the onset of acute icteric hepatitis; all 11 feces from days 8 to 15 were negative for HEV. Fecal concentrations of HEV appeared to be lower than those of many enteric viruses: only one specimen contained as many as 5 particles per EM grid square. It is concluded that HEV was etiologically associated with the epidemic and was predominantly excreted at very low levels during the first week of jaundice.
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Affiliation(s)
- J Ticehurst
- Department of Viral Diseases, Walter Reed Army Institute of Research, Washington, DC 20307-5100
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Lin YP, Nicholas K, Ball FR, McLaughlin B, Bishai FR. Detection of Norwalk-like virus and specific antibody by immune-electron microscopy with colloidal gold immune complexes. J Virol Methods 1991; 35:237-53. [PMID: 1667789 DOI: 10.1016/0166-0934(91)90066-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Direct electron-microscopy (DEM), immune electron microscopy (IEM) and four different procedures of immune electron microscopy with colloidal gold immune complexes were evaluated for the detection of Norwalk-like virus and specific antibody. A solid-phase immune electron microscopy with colloidal gold immune complexes-triple layer method (SPIEMGIC-TLM) is developed for screening patients' specimens for the detection of Norwalk-like virus and its specific antibody. The method demonstrates low non-specific background labelling and is simple, sensitive and easy to perform. A quadruple layer method (SPIEMGIC-QLM), which is a modification of the triple layer method, has been established by adding a cross-linking anti-IgG layer to amplify the reaction and to provide a more sensitive test which is suitable for screening monoclonal antibodies prepared against 32-34-nm Norwalk-like virus isolated in our laboratory.
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Affiliation(s)
- Y P Lin
- Laboratory Services Branch, Ontario Ministry of Health, Toronto, Canada
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McCaustland KA, Bi S, Purdy MA, Bradley DW. Application of two RNA extraction methods prior to amplification of hepatitis E virus nucleic acid by the polymerase chain reaction. J Virol Methods 1991; 35:331-42. [PMID: 1816258 DOI: 10.1016/0166-0934(91)90074-a] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Amplification of the enterically-transmitted non-A, non-B hepatitis virus (HEV) RNA using conventional reverse transcriptase reactions followed by the polymerase chain reaction (PCR) of the cDNA has not been successful. However, after application of two different RNA capture/extraction methods we were able to amplify HEV nucleic acid from clinical samples and specimens from experimentally infected animals. The first procedure, adapted from an immune electron microscopy (IEM) technique, incorporated an immunocapture step with concentration of the virus-antibody complexes by pelleting in a Beckman airfuge. In the second method, glass powder (or size-fractionated silicon dioxide) was used to capture the RNA from its surrounding milieu by adsorption of the nucleic acid to the silicate particles. Since conventional immunoassays for HEV antigen or antibody are not currently available, the use of these RNA extraction methods, coupled with PCR techniques, will be valuable in screening clinical specimens and in further defining the course of disease using animal infectivity studies.
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Affiliation(s)
- K A McCaustland
- Hepatitis Branch, Centers for Disease Control, Atlanta, GA 30333
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Moe CL, Allen JR, Monroe SS, Gary HE, Humphrey CD, Herrmann JE, Blacklow NR, Carcamo C, Koch M, Kim KH. Detection of astrovirus in pediatric stool samples by immunoassay and RNA probe. J Clin Microbiol 1991; 29:2390-5. [PMID: 1774241 PMCID: PMC270344 DOI: 10.1128/jcm.29.11.2390-2395.1991] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Two new astrovirus assays, a rapid biotin-avidin enzyme immunoassay (EIA) and RNA probe hybridization, were developed and compared with an established astrovirus assay, an indirect EIA, and immune electron microscopy. Sensitivity and specificity were evaluated by using a screening panel of 22 astrovirus-positive and 305 astrovirus-negative fecal specimens. The biotin-avidin assay was equivalent in performance to the reference indirect assay, and both could detect about 10 ng of viral protein. Although the probe was more sensitive than either EIA and could detect higher dilutions of virus in tissue culture and stool specimens, it did not detect more astrovirus-positive fecal specimens. Of the 22 astrovirus-positive specimens detected by the EIAs, 20 were confirmed by immune electron microscopy with hyperimmune rabbit antiserum. To determine the usefulness of EIAs for large epidemiologic studies, EIAs were used to screen 1,289 stool specimens from three studies of children with and without diarrhea. Astrovirus was detected in 3.5% of specimens from children with diarrhea and 1.9% of specimens from those without diarrhea. Our results indicate that the biotin-avidin EIA is an efficient, sensitive, and specific method for routinely screening large numbers of fecal samples and that its application in epidemiologic studies may yield higher rates of astrovirus infection than have been found previously by other methods.
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Affiliation(s)
- C L Moe
- Division of Viral and Rickettsial Diseases, Centers for Disease Control, Atlanta, Georgia 30333
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Diallo A, Lazizi Y, Le Guenno B, Pillot J. Hepatitis-E-virus-associated antigen: improved detection in stools by protein Fv removal. RESEARCH IN VIROLOGY 1991; 142:449-59. [PMID: 1666435 DOI: 10.1016/0923-2516(91)90067-d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
ELISA detection of a hepatitis-E-virus-associated antigen (HEV-AAg) in stools was reappraised for its possible interference with a new Fab-binding factor, termed protein Fv, released during infectious hepatitis. Transaminase elevation, HEV-AAg discharge and Fv leakage appeared simultaneously in a Cercopithecus monkey inoculated with infected stools. Labelled normal, or immune human IgG, were compared with pre- and post-inoculation simian IgG, for HEV-AAg and Fv detection. Coated normal and patient human IgM were also compared to pre- and post-inoculation simian IgM in HEV-AAg and Fv capture assays. Simian IgM and beta-galactosidase-labelled simian IgG minimized Fv interference and appeared to be the best adapted system for HEV-AAg detection. Nevertheless, Fv was still the cause of false-positive interpretations in some cases; therefore adsorption with monoclonal IgM was required to ensure HEV specificity. The improved test was performed on stools from 30 Senegalese patients hospitalized for various sporadic attacks of viral hepatitis. HEV-AAg was detected in 6 out of 30 cases and no positivity was observed in patients suffering from hepatitis due to HAV, HBV, cytomegalovirus or Epstein-Barr virus. The specificity of the assay was confirmed by inhibition experiments with the sera from HEV-infected patients. Hence, this inhibition assay can also be used to detect serum antibodies to HEV-AAg.
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Affiliation(s)
- A Diallo
- Laboratoire de Virologie, Institut Pasteur, Dakar
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Winokur PL, McLinden JH, Stapleton JT. The hepatitis A virus polyprotein expressed by a recombinant vaccinia virus undergoes proteolytic processing and assembly into viruslike particles. J Virol 1991; 65:5029-36. [PMID: 1651421 PMCID: PMC248966 DOI: 10.1128/jvi.65.9.5029-5036.1991] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Hepatitis A virus (HAV) contains a single-stranded, plus-sense RNA genome with a single long open reading frame encoding a polyprotein of approximately 250 kDa. Viral structural proteins are generated by posttranslational proteolytic processing of this polyprotein. We constructed recombinant vaccinia viruses which expressed the HAV polyprotein (rV-ORF) and the P1 structural region (rV-P1). rV-ORF-infected cell lysates demonstrated that the polyprotein was cleaved into immunoreactive 29- and 33-kDa proteins which comigrated with HAV capsid proteins VP0 and VP1. The rV-P1 construct produced a 90-kDa protein which showed no evidence of posttranslational processing. Solid-phase radioimmunoassays with human polyclonal anti-HAV sera and with murine or human neutralizing monoclonal anti-HAV antibodies recognized the rV-ORF-infected cell lysates. Sucrose density gradients of rV-ORF-infected cell lysates contained peaks of HAV antigen with sedimentation coefficients of approximately 70S and 15S, similar to those of HAV empty capsids and pentamers. Immune electron microscopy also demonstrated the presence of viruslike particles in rV-ORF-infected cell lysates. Thus, the HAV polyprotein expressed by a recombinant vaccinia virus demonstrated posttranslational processing into mature capsid proteins which assembled into antigenic viruslike particles.
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Affiliation(s)
- P L Winokur
- Department of Internal Medicine, University of Iowa College of Medicine, Iowa City
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Affiliation(s)
- J Y Lau
- Royal Free Hospital School of Medicine, London
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