scholarly journals PEDV Infection Generates Conformation-Specific Antibodies That Can Be Effectively Detected by a Cell-Based ELISA

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 303
Author(s):  
Wei-Ting Hsu ◽  
Chia-Yu Chang ◽  
Chih-Hsuan Tsai ◽  
Sung-Chan Wei ◽  
Huei-Ru Lo ◽  
...  
Keyword(s):  
Recombinant Baculovirus ◽  
Immunocytochemical Staining ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Perfect Agreement ◽  
Specific Antibodies ◽  
Diarrhea Virus ◽  
Serological Studies ◽  
A Cell ◽  
Infected Insect

Porcine epidemic diarrhea virus (PEDV) is a coronavirus that causes serious and highly contagious enteric disease in swine worldwide. In this study, we constructed a recombinant baculovirus (S-Bac) expressing full-length spike protein of the virulent epidemic genotype 2b (G2b) PEDV strain for serological studies of infected pigs. We found that most spike-specific antibodies produced upon PEDV infection in pigs are conformation-specific and they could be detected on S-Bac-infected insect cells by immunofluorescent assay, but they were insensitive to Western blot analysis, the typical method for antiserum analysis. These results indicated that spike conformation is crucial for serum recognition. Since it is difficult to purify trimeric spike membrane protein for conventional enzyme-linked immunosorbent assay (ELISA), we used S-Bac to generate a novel cell-based ELISA for convenient PEDV detection. We analyzed 100 pig serum samples, and our cell-based ELISA exhibited a sensitivity of 100%, a specificity of 97%, and almost perfect agreement [Cohen’s kappa coefficient value (κ) = 0.98] with immunocytochemical staining results. Our cell-based ELISA rapidly presented antigen for proper detection of conformation-specific antibodies, making PEDV detection more convenient, and it will be useful for detecting many viral diseases in the future.

scholarly journals Pestivirus Infections in Semi-Domesticated Eurasian Tundra Reindeer (Rangifer tarandus tarandus): A Retrospective Cross-Sectional Serological Study in Finnmark County, Norway

Viruses ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 29 ◽  
Author(s):  
Carlos G. das Neves ◽  
Jonas Johansson Wensman ◽  
Ingebjørg Helena Nymo ◽  
Eystein Skjerve ◽  
Stefan Alenius ◽  
...  
Keyword(s):  
Rangifer Tarandus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Border Disease Virus ◽  
Serum Samples ◽  
Cross Sectional ◽  
Diarrhea Virus ◽  
Border Disease ◽  
Serological Studies ◽  
Viral Diarrhea Virus

Members of the Pestivirus genus (family Flaviviridae) cause severe and economically important diseases in livestock. Serological studies have revealed the presence of pestiviruses in different cervid species, including wild and semi-domesticated Eurasian tundra reindeer. In this retrospective study, serum samples collected between 2006 and 2008 from 3339 semi-domesticated Eurasian reindeer from Finnmark County, Norway, were tested for anti-pestivirus antibodies using an enzyme linked immunosorbent assay (ELISA) and a subset of these by virus neutralization test (VNT). A seroprevalence of 12.5% was found, varying from 0% to 45% among different herding districts, and 20% in western Finnmark, as compared to 1.7% in eastern Finnmark. Seroprevalence increased with age. Pestivirus-specific RNA was not detected in any of the 225 serum samples tested by real-time RT-PCR. Based on VNT results, using a panel of one bovine viral diarrhea virus (BVDV) strain and two border disease virus (BDV) strains, the virus is most likely a reindeer-specific pestivirus closely related to BDV. A characterization of the causative virus and its pathogenic impact on reindeer populations, as well as its potential to infect other domestic and wild ruminants, should be further investigated.

scholarly journals Pestivirus infections in cervids from the Czech Republic

2009 ◽  
Vol 54 (No. 4) ◽  
pp. 191-193
Author(s):  
K. Sedlak ◽  
T. Girma ◽  
J. Holejsovsky
Keyword(s):  
Czech Republic ◽  
Cervus Elaphus ◽  
Red Deer ◽  
Competitive Inhibition ◽  
Enzyme Linked Immunosorbent Assay ◽  
Border Disease Virus ◽  
Serum Samples ◽  
The Czech Republic ◽  
Diarrhea Virus ◽  
Border Disease

372 sera of cervids from the Czech Republic were examined for antibodies to the bovine viral diarrhea virus (BVDV) and border disease virus (BDV) by competitive-inhibition enzyme-linked immunosorbent assay (ELISA), and for the presence of the BVDV by AgELISA. Antibodies to BVDV/BDV were found in 0.6% (two positive/305 tested) red deer (<I>Cervus elaphus</I>). BVDV/BDV antibodies were not found in four sika deer (<I>Cervus Nippon</I>) and 63 fallow deer (<I>Dama dama</I>). All serum samples were BVDV antigen negative. Our results confirmed that red deer in the Czech Republic are only rarely infected with Pestiviruses. This was the first survey of pestiviruses in farmed and wild cervids in the Czech Republic.

scholarly journals Standardization of dot-ELISA for the serological diagnosis of toxocariasis and comparision of the assay with ELISA

1992 ◽  
Vol 34 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Eide Dias Camargo ◽  
Paulo Mutuko Nakamura ◽  
Adelaide José Vaz ◽  
Marcos Vinícius da Silva ◽  
Pedro Paulo Chieffi ◽  
...  
Keyword(s):  
Low Cost ◽  
Clinical Signs ◽  
Toxocara Canis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Specific Antibodies ◽  
Normal Individuals ◽  
Before And After ◽  
Dot Elisa ◽  
Stability Time

The dot-enzyme-linked immunosorbent assay (dot-ELISA) was standardized using somatic (S) and excretory-secretory (ES) antigens of Toxocara-canis for the detection of specific antibodies in 22 serum samples from children aged 1 to 15 years, with clinical signs of toxocariasis. Fourteen serum samples from apparently normal individuals and 28 sera from patients with other pathologies were used as controls. All samples were used before and after absorption with Ascaris suum extract. When the results were evaluated in comparison with ELISA, the two tests were found to have similar sensitivity, but dot-ELISA was found to be more specific in the presence of the two antigens studied. Dot-ELISA proved to be effective for the diagnosis of human toxocariasis, presenting advantages in terms of yield, stability, time and ease of execution and low cost.

scholarly journals Development of Recombinant Nucleoprotein-Based Diagnostic Systems for Lassa Fever

2007 ◽  
Vol 14 (9) ◽  
pp. 1182-1189 ◽  
Author(s):  
Masayuki Saijo ◽  
Marie-Claude Georges-Courbot ◽  
Philippe Marianneau ◽  
Victor Romanowski ◽  
Shuetsu Fukushi ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Hela Cells ◽  
Recombinant Baculovirus ◽  
Lassa Fever ◽  
Rabbit Serum ◽  
Enzyme Linked Immunosorbent Assay ◽  
Lassa Virus ◽  
Diagnostic Systems ◽  
Serum Samples ◽  
Capture Elisa

ABSTRACT Diagnostic systems for Lassa fever (LF), a viral hemorrhagic fever caused by Lassa virus (LASV), such as enzyme immunoassays for the detection of LASV antibodies and LASV antigens, were developed using the recombinant nucleoprotein (rNP) of LASV (LASV-rNP). The LASV-rNP was expressed in a recombinant baculovirus system. LASV-rNP was used as an antigen in the detection of LASV-antibodies and as an immunogen for the production of monoclonal antibodies. The LASV-rNP was also expressed in HeLa cells by transfection with the expression vector encoding cDNA of the LASV-NP gene. An immunoglobulin G enzyme-linked immunosorbent assay (ELISA) using LASV-rNP and an indirect immunofluorescence assay using LASV-rNP-expressing HeLa cells were confirmed to have high sensitivity and specificity in the detection of LASV-antibodies. A novel monoclonal antibody to LASV-rNP, monoclonal antibody 4A5, was established. A sandwich antigen capture (Ag-capture) ELISA using the monoclonal antibody and an anti-LASV-rNP rabbit serum as capture and detection antibodies, respectively, was then developed. Authentic LASV nucleoprotein in serum samples collected from hamsters experimentally infected with LASV was detected by the Ag-capture ELISA. The Ag-capture ELISA specifically detected LASV-rNP but not the rNPs of lymphocytic choriomeningitis virus or Junin virus. The sensitivity of the Ag-capture ELISA in detecting LASV antigens was comparable to that of reverse transcription-PCR in detecting LASV RNA. These LASV rNP-based diagnostics were confirmed to be useful in the diagnosis of LF even in institutes without a high containment laboratory, since the antigens can be prepared without manipulation of the infectious viruses.

DETECTION OF SPECIFIC ANTIBODIES TO THE NUCLEOCAPSID PROTEIN FRAGMENTS OF SEVERE ACUTE RESPIRATORY SYNDROME-CORONAVIRUS AND SCOTOPHILUS BAT CORONAVIRUS-512 IN THREE INSECTIVOROUS BAT SPECIES

2018 ◽  
Vol 44 (04) ◽  
pp. 179-188 ◽  
Author(s):  
Yi-Ning Chen ◽  
Bo-Gang Su ◽  
Hung-Chang Chen ◽  
Cheng-Han Chou ◽  
Hsi-Chi Cheng
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Nucleocapsid Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Protein Fragments ◽  
Specific Antibodies ◽  
History Of ◽  
Polymerase Chain ◽  
Carboxyl Terminal ◽  
Bat Coronavirus

Bats are the natural reservoirs of severe acute respiratory syndrome-coronavirus (SARS-CoV). Six Alphacoronavirus and five Betacoronavirus have been detected in many bat species, including SARS-related CoV and Middle East respiratory syndrome (MERS)-related CoV. In Taiwan, SARS-related CoV, belonging to Betacoronavirus, has been detected in Rhinolophus monoceros. Scotophilus bat CoV-512, belonging to Alphacoronavirus, has been detected in Scotophilus kuhlii, Miniopterus fuliginosus, and Rhinolophus monoceros by using reverse transcription polymerase chain reaction (RT-PCR). To understand the infection history of CoV in these three insectivorous bat populations, CoV-specific antibodies were surveyed by using western blot (WB) analysis and indirect enzyme-linked immunosorbent assay (ELISA). The carboxyl terminal fragment of nucleocapsid protein (N3) of SARS-CoV and Scotophilus bat CoV-512 were used as the antigen in the assays. Of the 52 serum samples obtained from Scotophilus kuhlii, 29 samples (56%) were tested positive for Scotophilus bat CoV-512-specific antibodies through ELISA. Of the 63 serum samples obtained from Rhinolophus monoceros, 9 samples were tested positive for only SARS-CoV-specific antibodies, 7 samples were tested positive for only Scotophilus bat CoV-512-specific antibodies, and 16 samples (25.4%) were tested positive for both antibodies through WB analysis. Only 1 of 18 Miniopterus bat serum samples tested positive for Scotophilus bat CoV-512-specific antibodies through ELISA. Lactating female bats had higher positive rates of CoV-specific antibodies than non-lactating female and male bats did. Our findings were crucial for understanding CoV infection history in three insectivorous bat species and important for the control of bat-borne zoonosis diseases.

scholarly journals Development of an enzyme-linked immunosorbent assay (ELISA) for the detection of specific antibodies against an H7N7 and an H3N8 equine influenza virus

1984 ◽  
Vol 93 (3) ◽  
pp. 609-620 ◽  
Author(s):  
M. S. Denyer ◽  
J. R. Crowther ◽  
R. C. Wardley ◽  
R. Burrows
Keyword(s):  
Influenza Virus ◽  
Immunosorbent Assay ◽  
Solid Phase ◽  
Allantoic Fluid ◽  
Influenza Viruses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Equine Influenza Virus ◽  
Serum Samples ◽  
Specific Antibodies ◽  
Equine Influenza

SummaryThis paper describes a solid-phase microtitre plate enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to equine influenza viruses. Using egg-grown influenza viruses as the antigens attached to the solid phase, crossreactions were observed between an H7N7 equine virus (designated A1) and an H3N8 equine influenza virus (designated A2) when untreated antisera were tested. Absorption of antisera with egg-grown A/Porcine/Shope/1/33 influenza virus eliminated cross-reactive antibodies so that specific detection of anti-equine influenza A1 or A2 antibodies was possible.Examination of horse sera following vaccination with A1 and/or A2 isolates showed that antibodies were produced against antigen associated with egg allantoic fluid as well as against virus. Such antibodies were eliminated following the absorption of antisera with porcine influenza virus. Results using sera from horses with known vaccination histories confirmed that the ELISA preferentially detected antibodies homologous to the antigen attached to the solid phase and methods to evaluate the current serological state of individual horses by relating the titres of specific antibodies against equine influenza A1 and A2 isolates are shown. This ELISA provides a simple and rapid method of assessing specific antibodies from horse sera and offers advantages over the ‘routine’ HI and SRH assessments since it gives high precision, is economical of reagents and has the capacity to handle large numbers of serum samples.

scholarly journals Standardized Method of MeasuringAcanthamoeba Antibodies in Sera from Healthy Human Subjects

2001 ◽  
Vol 8 (4) ◽  
pp. 724-730 ◽  
Author(s):  
Cynthia L. Chappell ◽  
John A. Wright ◽  
Michael Coletta ◽  
Anthony L. Newsome
Keyword(s):  
Human Subjects ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Healthy Human ◽  
Serological Studies ◽  
Life Threatening ◽  
Assay Methods ◽  
Asymptomatic Infections ◽  
Acanthamoeba Culbertsoni ◽  
Positive Results

ABSTRACT Acanthamoeba species can cause serious, debilitating, and sometimes life-threatening infections. Three groups have been identified using morphological and immunological comparisons. Previous serological studies have utilized a variety of antigen preparations and assay methods and reported disparate (3 to 100%) results. This study was designed to (i) optimize an enzyme-linked immunosorbent assay for detecting serum antibodies to each of the Acanthamoebaserogroups and (ii) test 55 healthy individuals for specific immunoglobulin G reactivity. The highest signal-to-background ratio was found when 3,000 fixed, intact trophozoites per well were used with a 1:10 serum dilution. Sera yielding optical densities of <0.25 against all three Acanthamoeba serogroups were used to define the cutoff for positive results. The highest background reactivity with these sera was seen with Acanthamoeba polyphaga (serogroup 2), followed by Acanthamoeba culbertsoni (serogroup 3) andAcanthamoeba astronyxis (serogroup 1). Of 55 subjects tested, the highest number of positive results was seen with A. polyphaga (81.8%), followed by A. astronyxis(52.8%) and A. culbertsoni (40%). Seven serum samples (12.7%) were negative for all three Acanthamoebaserogroups, 16 (29.1%) were positive for one serogroup only, 16 were positive for two serogroups, and 16 reacted to all three serogroups. Further analysis showed no significant associations between serogroup reactivity and age or gender. However, some ethnic differences were noted, especially with A. polyphaga antigens. In that case, serum samples from Hispanic subjects were 14.5 times less likely to be positive (P = 0.0025) and had lower mean absorbance values (P = 0.047) than those from Caucasian subjects. Overall, these data suggest that Acanthamoeba colonization or infection is more common than previously thought. Mild or asymptomatic infections may contribute to the observed serum reactivities.

scholarly journals Detection of Specific Antibodies to an Antigenic Mannoprotein for Diagnosis of Penicillium marneffeiPenicilliosis

1998 ◽  
Vol 36 (10) ◽  
pp. 3028-3031 ◽  
Author(s):  
Liang Cao ◽  
Da-Liang Chen ◽  
Cindy Lee ◽  
Che-Man Chan ◽  
King-Man Chan ◽  
...  
Keyword(s):  
Specific Antibody ◽  
Blood Donors ◽  
Antibody Test ◽  
High Specificity ◽  
Pathogenic Fungi ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Specific Antibodies ◽  
Immunodeficiency Virus ◽  
Positive Results

The disseminated and progressive fungal disease Penicillium marneffei penicilliosis is one of the most common infectious diseases in AIDS patients in Southeast Asia. To diagnose systemic penicilliosis, we developed an enzyme-linked immunosorbent assay (ELISA)-based antibody test with Mp1p, a purified recombinant antigenic mannoprotein of P. marneffei. Evaluation of the test with guinea pig sera against P. marneffei and other pathogenic fungi indicated that this assay was specific for P. marneffei. Clinical evaluation revealed that high levels of specific antibody were detected in two immunocompetent penicilliosis patients. Furthermore, approximately 80% (14 of 17) of the documented penicilliosis patients with human immunodeficiency virus tested positive for the specific antibody. No false-positive results were found for serum samples from 90 healthy blood donors, 20 patients with typhoid fever, and 55 patients with tuberculosis, indicating a high specificity of the test. Thus, this ELISA-based test for the detection of anti-Mp1p antibody can be of significant value as a diagnostic for penicilliosis.

scholarly journals Sensitive detection of SARS-CoV-2-specific-antibodies in dried blood spot samples

2020 ◽  
Author(s):  
Gabriella L. Morley ◽  
Stephen Taylor ◽  
Sian Jossi ◽  
Marisol Perez-Toledo ◽  
Sian E. Faustini ◽  
...  
Keyword(s):  
Sampling Method ◽  
Dried Blood Spot ◽  
Serological Testing ◽  
Spike Glycoprotein ◽  
Serum Samples ◽  
Perfect Agreement ◽  
Specific Antibodies ◽  
Antibody Levels ◽  
Matched Samples ◽  
Blood Spot

AbstractImportancePopulation-wide serological testing is an essential component in understanding the COVID-19 pandemic. The logistical challenges of undertaking widespread serological testing could be eased through use of a reliable dried blood spot (DBS) sampling method.ObjectiveTo validate the use of dried blood spot sampling for the detection of SARS-CoV-2-specific antibodies.Design, setting and participantsEighty-seven matched DBS and serum samples were obtained from eighty individuals, including thirty-one who were previously PCR-positive for SARS-CoV-2. DBS eluates and sera were used in an ELISA to detect antibodies to the viral spike protein.ResultsSpecific anti-SARS-Cov-2 spike glycoprotein antibodies were detectable in both serum and DBS eluate and there was a significant correlation between the antibody levels detected in matched samples (r = 0.96, p<0.0001). Using serum as the gold standard in the assay, matched DBS samples achieved a Cohen’s kappa coefficient of 0.975 (near-perfect agreement), a sensitivity of 98.1% and specificity of 100%, for detecting anti-spike glycoprotein antibodies.Conclusions and relevanceEluates from DBS samples are a reliable and reproducible source of antibodies to be used for the detection of SARS-CoV-2-specific antibodies. The use of DBS sampling could complement the use of venepuncture in the immunosurveillance of COVID-19 in both low and high income settings.

Dot immunogold filtration assay (DIGFA) for the rapid detection of specific antibodies against the rat lungwormAngiostrongylus cantonensis(Nematoda: Metastrongyloidea) using purified 31-kDa antigen

2013 ◽  
Vol 88 (4) ◽  
pp. 396-401 ◽  
Author(s):  
P. Eamsobhana ◽  
X.X. Gan ◽  
A. Ma ◽  
Y. Wang ◽  
D. Wanachiwanawin ◽  
...  
Keyword(s):  
Large Scale ◽  
Protein A ◽  
Epidemiological Studies ◽  
Human Infection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Parasitic Diseases ◽  
Serum Samples ◽  
Specific Antibodies ◽  
North East ◽  
Gold Conjugate

AbstractA rapid dot immunogold filtration assay (DIGFA) was adopted for specific immunodiagnosis of human cerebral angiostrongyliasis, using purified 31-kDa glycoprotein specific toAngiostrongylus cantonensisas diagnostic antigen and protein A colloidal gold conjugate as antigen–antibody detector. A total of 59 serum samples were assayed – 11 samples from clinically diagnosed patients with detectableA. cantonensis-specific antibody in immunoblotting; 23 samples from patients with other related parasitic diseases, i.e. gnathostomiasis (n= 8), cysticercosis (n= 5), toxocariasis (n= 2), filariasis (n= 4), paragonimiasis (n= 2) and malaria (n= 2); and 25 samples from normal healthy subjects. The sensitivity and specificity of DIGFA to detect anti-A. cantonensisspecific antibodies in serologically confirmed angiostrongyliasis cases, were both 100%. No positive DIGFA was observed in cases with other parasitic diseases, and the healthy control subjects. The 3-min DIGFA is as sensitive and specific as the 3-h immunoblot test in angiostrongyliasis confirmed cases that revealed a 31-kDa reactive band. The gold-based DIGFA is more rapid and easier to perform than the traditional enzyme-linked immunosorbent assay (ELISA). The test utilizing purifiedA.cantonensisantigen is reliable and reproducible for specific immunodiagnosis of human infection withA. cantonensis– thus can be applied as an additional routine test for clinical diagnostic support. Large-scale sero-epidemiological studies in endemic communities in north-east Thailand are under way to evaluate its usefulness under field conditions.

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