scholarly journals Comparison of Three Immunoassays for Detection of Antibodies to Strongyloides stercoralis

2014 ◽  
Vol 21 (5) ◽  
pp. 732-736 ◽  
Author(s):  
Neil W. Anderson ◽  
Diane M. Klein ◽  
Sarina M. Dornink ◽  
Deborah J. Jespersen ◽  
Joseph Kubofcik ◽  
...  
Keyword(s):  
Strongyloides Stercoralis ◽  
Antibody Detection ◽  
Venn Diagram ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Perfect Agreement ◽  
Content Type ◽  
Culture Techniques ◽  
Intestinal Nematode ◽  
Diagram Analysis

ABSTRACTDue to the limited sensitivities of stool-based microscopy and/or culture techniques forStrongyloides stercoralis, the detection of antibodies to this intestinal nematode is relied upon as a surrogate for determining exposure status or making a diagnosis ofS. stercoralisinfection. Here, we evaluated three immunoassays, including the recently released InBios Strongy Detect IgG enzyme-linked immunosorbent assay (ELISA) (InBios International, Inc., Seattle, WA), the SciMedxStrongyloidesserology microwell ELISA (SciMedx Corporation, Denville, NJ), and the luciferase immunoprecipitation system (LIPS) assay performed at the National Institutes of Health (NIH), for their detection of IgG antibodies toS. stercoralis. A total of 101 retrospective serum samples, previously submitted for routineS. stercoralisantibody detection using the SciMedx assay, were also evaluated by the InBios and LIPS assays. The qualitative results from each assay were compared using a Venn diagram analysis, to the consensus result among the three assays, and each ELISA was also evaluated using the LIPS assay as the reference standard. By Venn diagram analysis, 65% (66/101) of the samples demonstrated perfect agreement by all three assays. Also, the numbers of samples considered positive or negative by a single method were similar. Compared to the consensus result, the overall percent agreement of the InBios, SciMedx, and LIPS assays were comparable at 87.1%, 84.2%, and 89.1%, respectively. Finally, the two ELISAs performed analogously but demonstrated only moderate agreement (kappa coefficient for the two assays, 0.53) with the LIPS assay. Collectively, while the two commercially available ELISAs perform equivalently, neither should be used independently of clinical evaluation to diagnose strongyloidiasis.

scholarly journals B-Cell-Specific Peptides of Leptospira interrogans LigA for Diagnosis of Patients with Acute Leptospirosis

2014 ◽  
Vol 21 (3) ◽  
pp. 354-359 ◽  
Author(s):  
Murugesan Kanagavel ◽  
Santhanam Shanmughapriya ◽  
Kumarasamy Anbarasu ◽  
Kalimuthusamy Natarajaseenivasan
Keyword(s):  
Early Diagnosis ◽  
B Cell ◽  
Predictive Value ◽  
Acute Stage ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Serological Tests ◽  
Content Type

ABSTRACTLeptospirosis is a reemerging infectious disease that is underdiagnosed and under-recognized due to low-sensitivity and cumbersome serological tests. Rapid reliable alternative tests are needed for early diagnosis of the disease. Considering the importance of the pathogenesis-associated leptospiral LigA protein expressedin vivo, we have evaluated its application in the diagnosis of the acute form of leptospirosis. The C-terminal coding sequence ofligA(ligA-C) was cloned into pET15b and expressed inEscherichia coli. Furthermore, the B-cell-specific epitopes were predicted and were synthesized as peptides for evaluation along with recombinant LigA-C. Epitope 1 (VVIENTPGK), with a VaxiJen score of 1.3782, and epitope 2 (TALSVGSSK), with a score of 1.2767, were utilized. A total of 140 serum samples collected from leptospirosis cases during the acute stage of the disease and 138 serum samples collected from normal healthy controls were utilized for evaluation. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated for the recombinant LigA-C-specific IgM enzyme-linked immunosorbent assay (ELISA) and were found to be 92.1%, 97.7%, 92.8%, and 97.5%, respectively. Epitopes 1 and 2 used in the study showed 5.1 to 5.8% increased sensitivity over recombinant LigA-C in single and combination assays for IgM antibody detection. These findings suggest that these peptides may be potential candidates for the early diagnosis of leptospirosis.

scholarly journals trans-Sialidase Neutralizing Antibody Detection in Trypanosoma cruzi-Infected Domestic Reservoirs

2011 ◽  
Vol 18 (6) ◽  
pp. 984-989 ◽  
Author(s):  
Paula A. Sartor ◽  
Martha V. Cardinal ◽  
Marcela M. Orozco ◽  
Ricardo E. Gürtler ◽  
M. Susana Leguizamón
Keyword(s):  
Visceral Leishmaniasis ◽  
Trypanosoma Cruzi ◽  
Neutralizing Antibodies ◽  
Cross Reactivity ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Trypanosoma Rangeli ◽  
Serum Samples ◽  
Dipstick Test ◽  
Content Type

ABSTRACTThe detection ofTrypanosoma cruziinfection in domestic dogs and cats is relevant to evaluating human transmission risks and the effectiveness of insecticide spraying campaigns. However, the serological assays routinely used are associated with cross-reactivity in sera from mammals infected withLeishmaniaspp. We used atrans-sialidase inhibition assay (TIA) forT. cruzidiagnosis in serum samples from 199 dogs and 57 cats from areas where these types of infections are endemic. TIA is based on the antibody neutralization of recombinanttrans-sialidase, an enzyme that is not detected in the coendemicLeishmaniaspecies orTrypanosoma rangeliparasites.T. cruziinfection was also evaluated by conventional serology (CS) (indirect immunofluorescence, indirect hemagglutination, enzyme-linked immunosorbent assay, and immunochromatographic dipstick test) and xenodiagnosis. Sera from 30 dogs and 15 cats from areas where these organisms are not endemic and 5 dogs with visceral leishmaniasis were found to be nonreactive by TIA and CS. Samples from dogs and cats demonstrated 91 and 95% copositivities between TIA and CS, whereas the conegativities were 98 and 97%, respectively. Sera from xenodiagnosis-positive dogs and cats also reacted by TIA (copositivities of 97 and 83%, respectively). TIA was reactive in three CS-negative samples and was able to resolve results in two cat serum samples that were CS inconclusive. Our study is the first to describe the development oftrans-sialidase neutralizing antibodies in naturally infected dogs and cats. High CS conegativity and the absence oftrans-sialidase neutralization in dog sera from areas where leishmaniasis is not endemic and from dogs with visceral leishmaniasis support TIA specificity. The TIA may be a useful tool forT. cruzidetection in the main domestic reservoirs.

scholarly journals Purification and Characterization of a Mycelial Catalase from Scedosporium boydii, a Useful Tool for Specific Antibody Detection in Patients with Cystic Fibrosis

2014 ◽  
Vol 22 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Sara Mina ◽  
Agnès Marot-Leblond ◽  
Bernard Cimon ◽  
Maxime J. J. Fleury ◽  
Gérald Larcher ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Hydrogen Peroxide ◽  
Species Complex ◽  
Respiratory Infections ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Microbial Infection ◽  
Phagocytic Cells ◽  
Serum Samples ◽  
Content Type

ABSTRACTScedosporium boydiiis an opportunistic filamentous fungus which may be responsible for a wide variety of infections in immunocompetent and immunocompromised individuals. This fungus belongs to theScedosporium apiospermumspecies complex, which usually ranks second among the filamentous fungi colonizing the airways of patients with cystic fibrosis (CF) and may lead to allergic bronchopulmonary mycoses, sensitization, or respiratory infections. Upon microbial infection, host phagocytic cells release reactive oxygen species (ROS), such as hydrogen peroxide, as part of the antimicrobial response. Catalases are known to protect pathogens against ROS by detoxification of the hydrogen peroxide. Here, we investigated the catalase equipment ofScedosporium boydii, one of the major pathogenic species in theS. apiospermumspecies complex. Three catalases were identified, and the mycelial catalase A1 was purified to homogeneity by a three-step chromatographic process. This enzyme is a monofunctional tetrameric protein of 460 kDa, consisting of four 82-kDa glycosylated subunits. The potential usefulness of this enzyme in serodiagnosis ofS. apiospermuminfections was then investigated by an enzyme-linked immunosorbent assay (ELISA), using 64 serum samples from CF patients. Whatever the species involved in theS. apiospermumcomplex, sera from infected patients were clearly differentiated from sera from patients with anAspergillus fumigatusinfection or those from CF patients without clinical and biological signs of a fungal infection and without any fungus recovered from sputum samples. These results suggest that catalase A1 is a good candidate for the development of an immunoassay for serodiagnosis of infections caused by theS. apiospermumcomplex in patients with CF.

scholarly journals Prevalence and clinical correlation of hepatitis E virus antibody in the patients’ serum samples from a tertiary care hospital in Thailand during 2015–2018

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Atiporn Boonyai ◽  
Anchalee Thongput ◽  
Thidarat Sisaeng ◽  
Parisut Phumchan ◽  
Navin Horthongkham ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Tertiary Care ◽  
Laboratory Data ◽  
Organ Transplant ◽  
Hospital Setting ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Care Hospital ◽  
Serum Samples ◽  
Igm Antibodies

Abstract Background Prevalence and incidence of hepatitis caused by HEV infection are usually higher in developing countries. This study demonstrated the HEV seroprevalence and incidence of HEV infection in patients with clinical hepatitis in a tertiary hospital in Thailand. Methods A laboratory-based cross-sectional study was conducted using 1106 serum samples from patients suspected of HEV infection sent to the Serology laboratory, Siriraj Hospital, for detecting HEV antibodies during 2015–2018. Prevalence of anti-HEV IgG and IgM antibodies in general patients, including organ transplant recipients and pregnant women in a hospital setting, were determined using indirect enzyme-linked immunosorbent assay (ELISA) kits. Comparison of laboratory data between groups with different HEV serological statuses was performed. Results HEV IgG antibodies were detected in 40.82% of 904 serum samples, while HEV IgM antibodies were detected in 11.75% of 1081 serum samples. Similar IgG and IgM antibody detection rates were found in pregnant women. Interestingly, anti-HEV IgM antibodies were detected in 38.5% of patients who underwent organ transplantation. Patients who tested positive for anti-HEV IgM antibodies had higher alanine aminotransferase levels than those who had not. In contrast, patients who tested positive for anti-HEV IgG had more elevated levels of total bilirubin than those who tested negative. Conclusions HEV seroprevalence and incidence in patients with clinical hepatitis were relatively high in the Thai population, including the pregnancy and organ transplant subgroups. The results potentially benefit the clinicians in decision-making to investigate HEV antibodies and facilitating proper management for patients.

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 Use of a Toxin Neutralization Assay To Characterize the Serologic Response to Adenylate Cyclase Toxin after Infection with Bordetella pertussis

2016 ◽  
Vol 24 (1) ◽  
Author(s):  
Joshua C. Eby ◽  
Mary C. Gray ◽  
Jason M. Warfel ◽  
Tod J. Merkel ◽  
Erik L. Hewlett
Keyword(s):  
Adenylate Cyclase ◽  
Bordetella Pertussis ◽  
Neutralization Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Immunologic Response ◽  
Serum Samples ◽  
Content Type ◽  
Adenylate Cyclase Toxin ◽  
Strong Candidate ◽  
Candidate Antigen

ABSTRACT Adenylate cyclase toxin (ACT) is an essential virulence factor of Bordetella pertussis, and antibodies to ACT protect against B. pertussis infection in mice. The toxin is therefore a strong candidate antigen for addition to future acellular pertussis vaccines. In order to characterize the functionality of the immunologic response to ACT after infection, we developed an assay for testing the ability of serum samples from subjects infected with B. pertussis to neutralize ACT-induced cytotoxicity in J774 macrophage cells. Baboons develop neutralizing anti-ACT antibodies following infection with B. pertussis, and all sera from baboons with positive anti-ACT IgG enzyme-linked immunosorbent assay (ELISA) results neutralized ACT cytotoxicity. The toxin neutralization assay (TNA) was positive in some baboon sera in which ELISA remained negative. Of serum samples obtained from humans diagnosed with pertussis by PCR, anti-ACT IgG ELISA was positive in 72%, and TNA was positive in 83%. All samples positive for anti-ACT IgG ELISA were positive by TNA, and none of the samples from humans without pertussis neutralized toxin activity. These findings indicate that antibodies to ACT generated following infection with B. pertussis consistently neutralize toxin-induced cytotoxicity and that TNA can be used to improve understanding of the immunologic response to ACT after infection or vaccination.

scholarly journals Diagnosis of Dengue Virus Infection by Detection of Specific Immunoglobulin M (IgM) and IgA Antibodies in Serum and Saliva

2003 ◽  
Vol 10 (2) ◽  
pp. 317-322 ◽  
Author(s):  
Angel Balmaseda ◽  
María G. Guzmán ◽  
Samantha Hammond ◽  
Guillermo Robleto ◽  
Carolina Flores ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Immunoglobulin M ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Serum Samples ◽  
Diagnostic Modality ◽  
Iga Antibodies ◽  
Specific Immunoglobulin ◽  
Feasible Alternative

ABSTRACT To evaluate alternative approaches to the serological diagnosis of dengue virus (DEN) infection, the detection of DEN-specific immunoglobulin M (IgM) and IgA antibodies in serum and saliva specimens was assessed in 147 patients with symptoms of DEN infection seen at the Ministry of Health in Nicaragua. Seventy-two serum samples were determined to be positive for anti-DEN antibodies by IgM capture enzyme-linked immunosorbent assay, the routine diagnostic procedure. Serum and saliva specimens were obtained from 50 healthy adults as additional controls. IgM was detected in the saliva of 65 of the 72 serum IgM-positive cases, 6 of the 75 serum IgM-negative cases, and none of the control group, resulting in a sensitivity of 90.3% and a specificity of 92.0% and demonstrating that salivary IgM is a useful diagnostic marker for DEN infection. Detection of IgA in serum may be another feasible alternative for the diagnosis of DEN infection, with serum IgA found in 68 (94.4%) of the IgM-positive cases. In contrast, detection of IgA in saliva was not found to be a useful tool for DEN diagnosis in the present study. Further studies of the kinetics of antibody detection in another set of 151 paired acute- and convalescent-phase serum samples showed that DEN-specific IgA antibodies were detected in more acute-phase samples than were IgM antibodies. Thus, we conclude that DEN-specific IgA in serum is a potential diagnostic target. Furthermore, given that saliva is a readily obtainable, noninvasive specimen, detection of DEN-specific salivary IgM should be considered a useful, cheaper diagnostic modality with similar sensitivity and specificity to IgM detection in serum.

scholarly journals Help in the Choice of Automated or Semiautomated Immunoassays for Serological Diagnosis of Toxoplasmosis: Evaluation of Nine Immunoassays by the French National Reference Center for Toxoplasmosis

2016 ◽  
Vol 54 (12) ◽  
pp. 3034-3042 ◽  
Author(s):  
O. Villard ◽  
B. Cimon ◽  
C. L'Ollivier ◽  
H. Fricker-Hidalgo ◽  
N. Godineau ◽  
...  
Keyword(s):  
Congenital Toxoplasmosis ◽  
Antibody Detection ◽  
Clinical Settings ◽  
Serum Samples ◽  
Igg Antibody ◽  
Routine Testing ◽  
Content Type ◽  
Specificity And Sensitivity ◽  
National Reference Center ◽  
Serology Testing

Toxoplasmosis, a benign infection, is asymptomatic or paucisymptomatic in over 80% of cases, except in immunocompetent patients suffering from ocular toxoplasmosis or in immunocompromised patients with opportunistic or congenital toxoplasmosis. Diagnosis is based mainly on serology testing. Thus, we compared the performance of the nine most commonly used commercial automated or semiautomated immunoassays for IgG and IgMToxoplasma gondiiantibody detection, that is, the Advia Centaur, Architect, AxSYM, Elecsys, Enzygnost, Liaison, Platelia, VIDAS, and VIDIA assays. The assays were conducted on four panels of serum samples derived during routine testing from patients with an interfering disease and who exhibited a low IgG antibody level in one of two clinical settings, namely, acute or chronic toxoplasmosis. As a result, IgG sensitivities ranged from 97.1% to 100%, and IgG specificities ranged from 99.5% to 100%. For IgG quantification, strong differences in IgG titers (expressed in IU/ml) were noted depending on the assay used. IgM sensitivities ranged from 65% to 97.9%, and IgM specificities ranged from 92.6% to 100%. For defining the best serological strategies to be implemented, it appears crucial to compare the diagnostic performance of the different tests with respect to their specificity and sensitivity in detecting the presence of IgG and IgM antibodies.

scholarly journals The latest FAD – Faecal antibody detection in cattle. Protocol and results from three UK beef farms naturally infected with gastrointestinal nematodes

Parasitology ◽  
2018 ◽  
Vol 146 (1) ◽  
pp. 89-96 ◽  
Author(s):  
A. S. Cooke ◽  
K. A. Watt ◽  
E. R. Morgan ◽  
J. A. J. Dungait
Keyword(s):  
Animal Health ◽  
Nematode Species ◽  
Gastrointestinal Nematodes ◽  
Vital Role ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Fecal Samples ◽  
Gastrointestinal Health ◽  
Immunological Protection

AbstractAntibodies at gastrointestinal mucosal membranes play a vital role in immunological protection against a range of pathogens, including helminths. Gastrointestinal health is central to efficient livestock production, and such infections cause significant losses. Fecal samples were taken from 114 cattle, across three beef farms, with matched blood samples taken from 22 of those animals. To achieve fecal antibody detection, a novel fecal supernatant was extracted. Fecal supernatant and serum samples were then analysed, using adapted enzyme-linked immunosorbent assay protocols, for levels of total immunoglobulin (Ig)A, IgG, IgM, andTeladorsagia circumcincta-specific IgA, IgG, IgM and IgE (in the absence of reagents for cattle-specific nematode species). Fecal nematode egg counts were conducted on all fecal samples. Assays performed successfully and showed that IgA was the predominant antibody in fecal samples, whereas IgG was predominant in serum. Total IgA in feces and serum correlated within individuals (0.581,P= 0.005), but other Ig types did not. Results support the hypothesis that the tested protocols are an effective method for the non-invasive assessment of cattle immunology. The method could be used as part of animal health assessments, although further work is required to interpret the relationship between results and levels of infection and immunity.

scholarly journals A Rapid Immunochromatography Test Based on Hcp1 Is a Potential Point-of-Care Test for Serological Diagnosis of Melioidosis

2018 ◽  
Vol 56 (8) ◽  
Author(s):  
Phornpun Phokrai ◽  
Wisansanee Karoonboonyanan ◽  
Nida Thanapattarapairoj ◽  
Chidchanok Promkong ◽  
Adul Dulsuk ◽  
...  
Keyword(s):  
Point Of Care ◽  
Clinical Manifestations ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Target Antigen ◽  
Northeast Thailand ◽  
Serum Samples ◽  
Serological Method ◽  
Healthy Donors ◽  
Wide Range

ABSTRACTMelioidosis is a fatal infectious disease caused by the environmental bacteriumBurkholderia pseudomallei. It is highly endemic in Asia and northern Australia but neglected in many other tropical countries. Melioidosis patients have a wide range of clinical manifestations, and definitive diagnosis requires bacterial culture, which can be time-consuming. A reliable rapid serological tool is greatly needed for disease surveillance and diagnosis. We previously demonstrated by enzyme-linked immunosorbent assay (ELISA) that a hemolysin-coregulated protein (Hcp1) is a promising target for serodiagnosis of melioidosis. In this study, we developed a rapid immunochromatography test (ICT) using Hcp1 as the target antigen (Hcp1-ICT). We evaluated this test for specific antibody detection using serum samples obtained from 4 groups of human subjects, including the following: (i) 487 culture-confirmed melioidosis patients from four hospitals in northeast Thailand; (ii) 202 healthy donors from northeast Thailand; (iii) 90 U.S. healthy donors; and (iv) 207 patients infected with other organisms. Compared to culture results as a gold standard, the sensitivity of ICT for all hospitals was 88.3%. The specificities for Thai donors and U.S. donors were 86.1% and 100%, respectively, and the specificity for other infections was 91.8%. The results of the Hcp1-ICT demonstrated 92.4% agreement with the Hcp1-ELISA results with a kappa value of 0.829, indicating that the method is much improved compared with the current serological method, the indirect hemagglutination assay (IHA) (69.5% sensitivity and 67.6% specificity for Thais). The Hcp1-ICT represents a potential point-of-care (POC) test and may be used to replace the IHA for screening of melioidosis in hospitals as well as in resource-limited areas.

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