Development of a Multiplex Bead Assay to Detect Immunoglobulin G Antibodies to Babesia duncani in Human Serum

2021 ◽  
Author(s):  
Yong Wang ◽  
TaLesa Aderohunmu ◽  
Henry Bishop ◽  
Isabel McAuliffe ◽  
Hilda N. Rivera ◽  
...  
Keyword(s):  
Fluorescent Antibody ◽  
Western United States ◽  
Spectrometric Analysis ◽  
Test Results ◽  
Specific Antibodies ◽  
Lower Specificity ◽  
Blood Donor Screening ◽  
Proteomics Approach ◽  
Multiplex Bead ◽  
Higher Sensitivity

Babesia duncani is the causative agent of babesiosis in the western United States. The indirect fluorescent antibody (IFA) assay is the diagnostic test of choice for detection of B. duncani specific antibodies. However, this test requires parasitized red blood cells harvested from infected hamsters and test results are often difficult to interpret. To simplify serological testing for B. duncani , a proteomics approach was employed to identify candidate immunodiagnostic antigens. Several proteins were identified by electrospray ionization (ESI) mass spectrometric analysis and four recombinant protein constructs were expressed and used in a multiplex bead assay (MBA) to detect B. duncani -specific antibodies. Two antigens, AAY83295.1 and AAY83296.1, performed well with high sensitivities and specificities. AAY83295.1 had a higher sensitivity (100%) but lower specificity (89%) in comparison to AAY83296.1, which had a sensitivity of 90% and a specificity of 96%. Combining these two antigens did not improve the performance of the assay. This MBA could be useful for diagnosis, serosurveillance, and blood donor screening for B. duncani infection.

scholarly journals SARS-CoV-2 specific antibody responses in COVID-19 patients

2020 ◽  
Author(s):  
Nisreen M.A. Okba ◽  
Marcel A. Müller ◽  
Wentao Li ◽  
Chunyan Wang ◽  
Corine H. GeurtsvanKessel ◽  
...  
Keyword(s):  
Evaluation Studies ◽  
Epidemiological Studies ◽  
Antibody Responses ◽  
Contact Tracing ◽  
Viral Reservoir ◽  
Molecular Diagnostic ◽  
Serum Samples ◽  
Specific Antibodies ◽  
Lower Specificity ◽  
Higher Sensitivity

AbstractA new coronavirus, SARS-CoV-2, has recently emerged to cause a human pandemic. Whereas molecular diagnostic tests were rapidly developed, serologic assays are still lacking, yet urgently needed. Validated serologic assays are important for contact tracing, identifying the viral reservoir and epidemiological studies. Here, we developed serological assays for the detection of SARS-CoV-2 neutralizing, spike- and nucleocapsid-specific antibodies. Using serum samples from patients with PCR-confirmed infections of SARS-CoV-2, other coronaviruses, or other respiratory pathogenic infections, we validated and tested various antigens in different in-house and commercial ELISAs. We demonstrate that most PCR-confirmed SARS-CoV-2 infected individuals seroconverted, as revealed by sensitive and specific in-house ELISAs. We found that commercial S1 IgG or IgA ELISAs were of lower specificity while sensitivity varied between the two, with IgA showing higher sensitivity. Overall, the validated assays described here can be instrumental for the detection of SARS-CoV-2-specific antibodies for diagnostic, seroepidemiological and vaccine evaluation studies.

Fluorescent antibody techniques have allowed for the direct identification and enumeration of individual bacteria in environmental samples without requiring prior growth in culture media (Bahlool and Schmidt 1980, Cloete and Steyn 1988, Macario et al. 1989). The technique involves the use of specific antibodies raised against surface markers of defined pure cultures that are either labelled directly with fluorescent dye molecules or via a fluorescent secondary antibody. This approach has yielded important insights into the spatial distribution of microorganisms, but it suffers from a number of disadvantages. For example, expression of the antigen may be influenced by environmental factors; false-positive and false-negative results may be obtained due to cross-reactivity or lack of reaction; non-specific binding of antibodies may result in high levels of background fluorescence; and production of specific antibodies requires a pure culture of the organism of interest (Cloete and de Bruyn Various recombinant DNA techniques have subsequently been developed that are independent of cultivation methods (Fig. 1). These techniques provide ways of detecting and quantifying specific phylogenetic groups of microbes on 16S rDNA sequences, and relevant structural genes provide ways of monitoring microbial populations of environmental and industrial systems. In addition to these tools, a number of emerging technologies such as the use of biomarker genes are being increasingly used to monitor with great precision and accuracy the behaviour of microbes in the environment.

2003 ◽  
pp. 218-219
Keyword(s):  
Recombinant Dna ◽  
Culture Media ◽  
Specific Binding ◽  
Fluorescent Antibody ◽  
False Negative ◽  
Cross Reactivity ◽  
Phylogenetic Groups ◽  
Specific Antibodies ◽  
Negative Results ◽  
Recombinant Dna Techniques

scholarly journals Risk Assessment in Chinese Hospitalized Patients Comparing the Padua and Caprini Scoring Algorithms

2018 ◽  
Vol 24 (9_suppl) ◽  
pp. 127S-135S ◽  
Author(s):  
Xiaolan Chen ◽  
Lei Pan ◽  
Hui Deng ◽  
Jingyuan Zhang ◽  
Xinjie Tong ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Venous Thrombosis ◽  
Deep Venous Thrombosis ◽  
Blood Platelets ◽  
Predictive Ability ◽  
Hospitalized Patients ◽  
Surgical Patients ◽  
Receiver Operating Curve ◽  
Lower Specificity ◽  
Higher Sensitivity

The current venous thromboembolism (VTE) guidelines recommend all patients to be assessed for the risk of VTE using risk assessment models (RAMs). The study was to evaluate the performance of the Caprini and Padua RAMs among Chinese hospitalized patients. We reviewed data from 189 patients with deep venous thrombosis (DVT) and 201 non-DVT patients. Deep venous thrombosis risk factors were obtained from all patients. The sensitivity and specificity of the Caprini and Padua scores for all patients were calculated. The receiver operating curve (ROC) and the area under the ROC curve (AUC) were used to evaluate the performance of each score. We documented that age, acute infection, prothrombin time (PT), D-dimer, erythrocyte sedimentation rate, blood platelets, and anticoagulation were significantly associated with the occurrence of DVT ( P < .05). These results were true for all medical and surgical patients group (G1), as well as the analysis of medical versus surgical patients (G2). Finally, analysis of the scores in patients with and without cancer was also done (G3). The Caprini has a higher sensitivity but a lower specificity than the Padua ( P < .05). Caprini has a better predictive ability for the first 2 groups ( P < .05). We found Caprini and Padua scores have a similar predictive value for patients with cancer ( P > .05), while Caprini has a higher predictive ability for no cancer patients in G3 than Padua ( P < .05). For Chinese hospitalized patients, Caprini has a higher sensitivity but a lower specificity than Padua. Overall, Caprini RAM has a better predictive ability than Padua RAM.

scholarly journals Application of the 2017 McDonald criteria in a Chinese population with clinically isolated syndrome

2020 ◽  
Vol 13 ◽  
pp. 175628641989808
Author(s):  
Yang Zheng* ◽  
Chun-Hong Shen* ◽  
Sa Wang ◽  
Fan Yang ◽  
Meng-Ting Cai ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Diagnostic Performance ◽  
Age Of Onset ◽  
Asian Population ◽  
Tertiary Hospital ◽  
Clinically Isolated Syndrome ◽  
Chinese Patients ◽  
Mcdonald Criteria ◽  
Lower Specificity ◽  
Higher Sensitivity

Background: Diagnostic criteria for multiple sclerosis have evolved over time, with the most recent being the 2017 McDonald criteria. Evidence is lacking regarding the validity of the 2017 McDonald criteria among the Asian population. Therefore, this study aims to evaluate the diagnostic performance of the 2017 McDonald criteria in Chinese patients with clinically isolated syndrome (CIS). Methods: A total of 93 patients with initial findings suggestive of CIS in a tertiary hospital in China from 2012 to 2017 were included in this retrospective study. Baseline and follow-up data were reviewed. Diagnostic performance (sensitivity, specificity, accuracy), was assessed and survival analysis was performed for the 2017 and 2010 McDonald criteria respectively. Results: Among the 93 Chinese patients with CIS, 57 were female (61.3%) and the median (interquartile range) age of onset was 37 (31.3–41.8) years. The 2017 McDonald criteria displayed a higher sensitivity (75.0% versus 14.6%, p < 0.0001), lower specificity (47.1% versus 100.0%, p < 0.05) but an overall higher accuracy (67.7% versus 36.9%, p < 0.0001) when compared with the 2010 iteration. The novel criteria allow for a better detection of MS at baseline (40.8% versus 9.9%, p < 0.0001). Conclusion: The 2017 McDonald criteria had a higher sensitivity but lower specificity than the 2010 iteration. Overall it facilitated an earlier and more accurate diagnosis of multiple sclerosis in Chinese patients with CIS.

The cestocidal effect of complement in normal and immune sera in vitro

Parasitology ◽  
1976 ◽  
Vol 72 (3) ◽  
pp. 325-334 ◽  
Author(s):  
E. P. Herd
Keyword(s):  
Immune System ◽  
Fluorescent Antibody ◽  
Specific Antibodies ◽  
Alternate Pathway ◽  
Wide Range ◽  
Lethal Reaction ◽  
Precipitation Reactions ◽  
Antigen Antibody ◽  
The Complement System

SummaryThe effects of complement and/or specific antibodies on the larval and adult stages of Echinococcus granulosus were studied in vitro. Lysis and death of both protoscoleces and adult E. granulosus occurred within 10 min to 24 h in 50% fresh normal sera used as a source of complement, without the presence of specific antibodies. The lytic and lethal reaction was marked in fresh sera from guinea-pigs, calves, dogs, man and sheep, but only slight in fresh sera from English rabbits and horses. Guinea-pig sera were shown to be complement deficient after reacting with worms and all reactions were abolished after sera had been heated to 56 °C for 30 min. Fluorescent antibody studies failed to detect host antibodies at the parasite tegument. It is suggested that activation of the complement system occurs via the alternate pathway, that it acts independently of the immune system and that it is lethal to a wide range of cestode parasites.In contrast, marked agglutination/precipitation reactions with protoscoleces and precipitation reactions with adult E. granulosus were observed after incubation in heat inactivated 50% canine antisera, but not in normal sera. The antigen-antibody nature of these reactions was established by fluorescent antibody studies and the areas of antibody attack pinpointed. In spite of these reactions, worms remained healthy and active over a period of 8 days.

A Novel Kind of Turbidity Sensor and its Measurement Method

2012 ◽  
Vol 424-425 ◽  
pp. 1253-1257
Author(s):  
Xing Qiao Liu ◽  
Peng Zhang
Keyword(s):  
Measurement Accuracy ◽  
Test Results ◽  
Measurement Circuit ◽  
The Core ◽  
On Line ◽  
New Type ◽  
The Impact ◽  
Sensor Probe ◽  
Easy Operation ◽  
Higher Sensitivity

In this paper, the scattering measuring principle of turbidity is introduced firstly. The new type of turbidity sensor probe designed in this paper overcomes the deficiencies of existing technologies, which has higher sensitivity, strong anti-interference and can detect the turbidity accurately and continuously. The system designed with the core of MCU C8051F020 is presented. Then the design of turbidity sensor probe, data acquisition, processing and non-linear compensation are introduced in detail. Besides, in order to eliminate the impact of temperature on the turbidity measurement and improve the measurement accuracy, temperature measurement circuit has been designed. Test results have shown that the designed on-line turbidity-meter has some advantages: low price, high precision, easy operation etc. It can be widely applied in the fields of waterworks, industrial production, aquaculture, environmental protection and so on

scholarly journals Evaluation of immunologic response of salivary sIg-A in pediatric tuberculosis patients to antigen Ag38-rec of Mycobacterium tuberculosis Indonesian strain

F1000Research ◽  
2015 ◽  
Vol 4 ◽  
pp. 1267
Author(s):  
Tri Yudani Mardining Raras ◽  
Diah Erma Pritta Santi ◽  
HMS Chandra Kusuma
Keyword(s):  
Immune Response ◽  
Mycobacterium Tuberculosis ◽  
Immunoglobulin A ◽  
Healthy Children ◽  
Dot Blot ◽  
Lower Specificity ◽  
Salivary Secretory Immunoglobulin A ◽  
Pediatric Tuberculosis ◽  
Secretory Immunoglobulin ◽  
Higher Sensitivity

Objective: We studied the immune response of salivary secretory immunoglobulin A (sIg-A) from a pediatric tuberculosis (TB) group (scoring of 6) and non-TB group (scoring <6) against recombinant Ag38 (Ag38-rec) fromMycobacterium tuberculosis Indonesian strain.Materials and Methods: Seventy-eight children were divided into three groups; those with TB (n=26), those with suspected TB (n=26), and healthy children (n=26), their saliva was collected, and salivary sIg-A was challenged with purified Ag38-rec using the dot blot method. A change of color from white to dark blue indicated a positive reaction.Results: The immune response of sIg-A of children with TB and those with suspected TB to Ag38-rec was not significantly different. In the TB group, Ag38-rec showed a higher sensitivity than protein purified derivative (PPD) (70.8% vs. 62.5%), but a lower specificity (26.9% vs. 34.62%). However, within both groups (scoring of 6) as well as non-TB group (scoring <6) Ag38-rec was able to identify children with a positive TST (tuberculin skin test) better than PPD.Conclusion: The antigen Ag38-rec could not distinguish between children with TB scores of 6 and <6.1. However, it demonstrated the potential of Ag38-rec for use in screening for TB infection among children with suspect TB (scores <6).

scholarly journals SARS-CoV-2-specific antibody detection for sero-epidemiology: a multiplex analysis approach accounting for accurate seroprevalence

2020 ◽  
Author(s):  
Gerco den Hartog ◽  
Rutger M. Schepp ◽  
Marjan Kuijer ◽  
Corine GeurtsvanKessel ◽  
Josine van Beek ◽  
...  
Keyword(s):  
Multiplex Assay ◽  
Spike Protein ◽  
Antibody Detection ◽  
Test Results ◽  
Detailed Understanding ◽  
Protein Subunits ◽  
Specific Antibodies ◽  
Single Antigen ◽  
Specific Igg ◽  
Kinetics Of

ABSTRACTBackgroundThe COVID-19 pandemic demands detailed understanding of the kinetics of antibody production induced by infection with SARS-CoV-2. We aimed to develop a high throughput multiplex assay to detect antibodies to SARS-CoV-2 to assess immunity to the virus in the general population.MethodsSpike protein subunits S1 and RBD, and Nucleoprotein were coupled to distinct microspheres. Sera collected before the emergence of SARS-CoV-2 (N=224), and of non-SARS-CoV-2 influenza-like illness (N=184), and laboratory-confirmed cases of SARS-CoV-2 infection (N=115) with various severity of COVID-19 were tested for SARS-CoV-2-specific concentrations of IgG.ResultsOur assay discriminated SARS-CoV-2-induced antibodies and those induced by other viruses. The assay obtained a specificity between 95.1 and 99.0% with a sensitivity ranging from 83.6-95.7%. By merging the test results for all 3 antigens a specificity of 100% was achieved with a sensitivity of at least 90%. Hospitalized COVID-19 patients developed higher IgG concentrations and the rate of IgG production increased faster compared to non-hospitalized cases.ConclusionsThe bead-based serological assay for quantitation of SARS-CoV-2-specific antibodies proved to be robust and can be conducted in many laboratories. Finally, we demonstrated that testing of antibodies against different antigens increases sensitivity and specificity compared to single antigen-specific IgG determination.

scholarly journals COMPARISON OF ARTIFICIAL INTELLIGENCE ENABLED METHODS IN THE COMPUTED TOMOGRAPHIC ASSESSMENT OF COVID-19 DISEASE.

2020 ◽  
Author(s):  
Atul Kapoor ◽  
Goldaa Mahajan ◽  
Aprajita Kapoor
Keyword(s):  
Artificial Intelligence ◽  
Sensitivity And Specificity ◽  
Visual Analysis ◽  
Test Results ◽  
Friedman Test ◽  
Rt Pcr ◽  
Computed Tomographic ◽  
Sensitivity Specificity ◽  
Disease Parameters ◽  
Higher Sensitivity

Objectives: Comparison of three different Artificial intelligence (AI) methods of assessment for patients undergoing Computed tomography (CT) for suspected Covid-19 disease. Parameters studied were probability of diagnosis, quantification of disease severity and the time to reach the diagnosis . Methods: 107 consecutive patients of suspected Covid-19 patients were evaluated using the three AI methods labeled as AI-I,II, III alongwith visual analysis labeled as VT for predicting probability of Covid-19, determining CT severity score (CTSS) and index (CTSI) , percentage opacification (PO) and high opacification (POHO). Sensitivity, specificity along with area under curves were estimated for each method and the CTSS and CTSI correlated using Friedman test. Results: Out of 107 patients 71 patients were Covid-19 positive and 20 negative by RT-PCR while 16 did not get RT-PCR done. AI-III method showed higher sensitivity and specificity of 93% and 88% respectively to predict probability of Covid 19. It had 2 false positive patients of interstitial lung disease. AI-II method had sensitivity and specificity of 66% and 83% respectively while visual (VT) analysis showed sensitivity and specificity of 59.7% and 62% respectively. Statistically significant differences were also seen in CTSI and PO estimation between AI-I and III methods (p<0.0001) with AI-III showing fastest time to calculate results. Conclusions: AI-III method gave better results to make an accurate and quick diagnosis of the Covid-19 with AUC of 0.85 to predict probability of Covid-19 alongwith quantification of Covid-19 lesions in the form of PO, POHO as compared to other AI methods and also by visual analysis.

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