Comparison of Three Enzyme-Linked Immunosorbent Assays for Serologic Diagnosis of Contagious Agalactia in Sheep

Serologic diagnosis of ovine contagious agalactia ( Mycoplasma agalactiae) with the enzyme-linked immunosorbent assay (ELISA) developed by Agence Française de Séceurité Sanitaire des Aliments (AFS-SA) may produce a few false-positive (FP) and false-negative (FN) results. When the prevalence of disease is low, these erroneous results may generate problems for eradication schemes. To prevent this, 2 commercial ELISAs were compared with the AFSSA ELISA. Flocks of known status were selected and classified into 4 categories: true positive (TP), FP, true negative (TN), and FN; 20 sheep per flock were submitted for blood sampling. A flock was considered positive when at least 1 out of 20 sera was positive or 2 sera were doubtful. In the flock, the diagnostic sensitivity of the 3 kits was very good (100%), and the diagnostic specificity showed an improvement from 46% (AFSSA test) to 88% and 92% (commercial tests). Considering individual animals, very few positive ewes were detected within TN or FP flocks; the proportion of positive ewes varied greatly from one kit to another (48% to 82%) within TP flocks. The kinetics of antibody response in sheep experimentally infected with various field strains of M. agalactiae were quite similar with all 3 ELISAs. The agreement between the 3 tests, assessed using the kappa value, varied from moderate to good (respective values of 0.56, 0.61, and 0.86). The 2 commercial ELISAs showed better performances, probably because of a superior analytical sensitivity, and are a good alternative for the serodiagnosis of contagious agalactia in sheep.

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Comparative Analysis of the Analytical Sensitivity of ELISA Test System DIA®-SARS-CoV-2-Ag-R with Rapid Tests for Viral Antigen SARS-CoV-2 Detection

Mikrobiolohichnyi Zhurnal ◽

10.15407/microbiolj83.03.066 ◽

2021 ◽

Vol 83 (3) ◽

pp. 66-71

Author(s):

А.Y. Horlov ◽

◽

V.H. Serdiuk ◽

О.K. Kiselova ◽

A.O. Shevchuk ◽

...

Keyword(s):

Viral Antigen ◽

False Negative ◽

Medical Science ◽

Rapid Test ◽

Test System ◽

Elisa Test ◽

Enzyme Linked Immunosorbent Assay ◽

Analytical Sensitivity ◽

Rapid Tests ◽

Positive Results

A novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease (COVID)-19, that emerged as a major pandemic. SARS-CoV-2 was identified as a betacoronavirus. Nucleocapsid protein (NP) is evolutionary high protein homologies and solid structure protein for SARS-CoV-2 detection as opposed to other proteins, that aren`t reliable as a single viral antigen during diagnostics methods. The viral RNA can be detected from nasal and pharyngeal swabs and bronchoalveolar lavage samples by PCR assay. However, the wrong collection of samples can lead to false-negative diagnosis and have dangerous consequences at this stage of pandemic. One of efficient and accurate methodological approaches for the screening of pathogens are serological assays. Aim. Evaluation and comparison of the sensitivity of invented DIA®-SARS-CoV-2-Ag-R enzyme-linked immunosorbent assay (ELISA)-based test system and commercial rapid tests, which detect the viral antigen of SARS-CoV-2. Methods. We carried out a comparison of DIA®-SARS-CoV-2-Ag-R and existed commercial test systems, which are used to detect the antigen of SARS-CoV-2 virus. Rapid tests are intended for nasopharyngeal swabs, but we proposed a protein of our own manufacture – recombinant NP as a calibrator. The detection limit was calibrated by standard CFAR #100982 NIBSC, UK. We had determined levels of NP (1400, 900, 750, 640 and 280 pg/mL) that we used as a sample for the rapid tests. The COVID-19 Ag Rapid Tests were performed according to the manufactures instructions at room temperature. Results. DIA®-SARS-CoV-2-Ag-R detected 10 pg/mL of in-house standard of recombinant SARS-CoV-2 NP. The positive results were observed using 1400, 900, 750 pg/mL, while 640 and 280 pg/mL samples were performed as negative in ABBOTT-PanBio test. The rapid tests manufactured by МBU, BIOTIME, Core Technology, SD BIOSENSOR and Turklab showed positive results only in 1400 pg/mL concentration. NP of lower levels was detected as a negative sample. The LEPU MEDICAL test was evaluated as positive sample using 900 pg/mL. The rapid test manufactured by Green Cross Medical Science Corp. showed negative results for all levels of NP. It can mean that the sensitivity of test is lower and demands higher level of antigen to detect the presence of SARS-CoV-2. Conclusions. The study presented an excellent analytical sensitivity of DIA®-SARS-CoV-2-Ag-R against commercial Antigen rapid tests. Thus, invented ELISA test system can be recommended for widespread usage for detection and confirmation of acute stage of SARS-CoV-2 infection.

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Sensitivity and Kinetics of an NS1-Based Zika Virus Enzyme-Linked Immunosorbent Assay in Zika Virus-Infected Travelers from Israel, the Czech Republic, Italy, Belgium, Germany, and Chile

Journal of Clinical Microbiology ◽

10.1128/jcm.00346-17 ◽

2017 ◽

Vol 55 (6) ◽

pp. 1894-1901 ◽

Cited By ~ 48

Author(s):

Yaniv Lustig ◽

Hana Zelena ◽

Giulietta Venturi ◽

Marjan Van Esbroeck ◽

Camilla Rothe ◽

...

Keyword(s):

Czech Republic ◽

Immunosorbent Assay ◽

Zika Virus ◽

False Negative ◽

Cross Reactivity ◽

Diagnostic Methods ◽

Antibody Detection ◽

Enzyme Linked Immunosorbent Assay ◽

Igg Antibodies ◽

Kinetics Of

ABSTRACT Serological diagnosis of Zika virus is challenging due to high cross-reactivity of Zika virus with other flavivirus antibodies. Recently, a Zika NS1-based enzyme-linked immunosorbent assay (ELISA) was developed and shown to be highly specific for Zika antibody detection; however, sensitivity was evaluated for only a small number of confirmed Zika-infected patients. In this study, we measured the sensitivity and kinetics of Zika IgM and IgG antibodies using the Zika NS1-based ELISA in 105 samples from 63 returning travelers infected with Zika virus (proven by PCR or neutralization assay) from Israel, Czech Republic, Italy, Belgium, Germany, and Chile. Zika virus IgM was detected from 2 to 42 days post-symptom onset (PSO) with an overall sensitivity of 79% in the first month and 68% until 2 months PSO, while IgG antibodies were detected from 5 days to 3 years PSO with 79% sensitivity. Interestingly, significant differences in IgM sensitivity and IgM detection period were observed between Israeli and European/Chilean Zika-infected travelers, adding to the complexity of Zika infection diagnosis and suggesting that other diagnostic methods should be complemented to reduce false-negative results.

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Detection of False-Positive Sera in Contagious Agalactia with a Multiantigen ELISA and their Elimination with a Protein G Conjugate

Journal of Veterinary Diagnostic Investigation ◽

10.1177/104063879801000403 ◽

1998 ◽

Vol 10 (4) ◽

pp. 326-330 ◽

Cited By ~ 12

Author(s):

Maurice Lambert ◽

Michel Calamel ◽

Philippe Dufour ◽

Evelyne Cabasse ◽

Christian Vitu ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Immunosorbent Assay ◽

False Positive ◽

Enzyme Linked Immunosorbent Assay ◽

Protein G ◽

Mycoplasma Agalactiae ◽

Cross Reactions ◽

Serologic Diagnosis ◽

Contagious Agalactia ◽

The Past

In serology, lack of specificity can generally be attributed to cross-reactions between different pathogens with antigens bearing similar epitopes. During seroepidemiologic surveys of contagious agalactia of sheep caused by Mycoplasma agalactiae infection, numerous sera were analyzed by enzyme-linked immunosorbent assay (ELISA). A few sera reacted with various antigens coated on plates, including the well with no antigen. This reactivity was not due to cross-reactions as initially suspected, and these multipositive sera were designated false-positive sera. Elimination of this false positivity was not possible by using covalent ELISA plates or different rabbit anti-sheep IgG conjugates. Only conjugates using monoclonal antibodies or protein G were efficient in elimination of false positivities without reducing the true specific positive titers. No false-positive sera have been observed since the implementation of protein G conjugates in the serologic diagnosis of contagious agalactia by ELISA for the past 2 years.

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Comparison of ELISA and RT-PCR versus Immune Electron Microscopy for Detection of Bovine Torovirus (Breda Virus) in Calf Fecal Specimens

Journal of Veterinary Diagnostic Investigation ◽

10.1177/104063870301500203 ◽

2003 ◽

Vol 15 (2) ◽

pp. 100-106 ◽

Cited By ~ 11

Author(s):

Armando E. Hoet ◽

Kyeong-Ok Chang ◽

Linda J. Saif

Keyword(s):

Epidemiological Survey ◽

Epidemiological Studies ◽

Diagnostic Techniques ◽

Enzyme Linked Immunosorbent Assay ◽

Analytical Sensitivity ◽

Rt Pcr ◽

Cutoff Value ◽

Kappa Value ◽

Sensitivity Specificity

Bovine Torovirus (BoTV) is an uncultivable enteric pathogen of cattle. Its failure to grow in vitro limits epidemiological studies, characterization of the virus, and development of diagnostic techniques. The objectives of this study were to develop and standardize an antigen-capture enzyme-linked immunosorbent assay (ELISA) and a reverse transcriptase-polymerase chain reaction (RT-PCR) assay for the detection of BoTV in fecal specimens. These assays were compared with immunoelectron microscopy (IEM) to evaluate their sensitivity, specificity, and efficiency as well as their advantages and limitations. Additionally, several methods to calculate ELISA cutoff values were used and compared using a statistical approach to obtain the optimal cutoff value for the ELISA. A plate cutoff ELISA value was determined to be the best method to calculate the cutoff value. The ELISA and RT-PCR assays developed in this study identified BoTV antigen and viral nucleic acids in feces without cross-reactions with the other calf enteric viruses examined. Both assays showed good agreement with IEM, with a Kappa value of 0.86 for ELISA and 0.85 for RT-PCR. The latter exhibited the higher analytical sensitivity. On the basis of the results obtained in this study, it is recommended that no single test should be used alone in an epidemiological survey because of the observed limitations of each assay. The fast and inexpensive ELISA combined with the highly specific and sensitive RT-PCR are a practical approach for future epidemiological studies of BoTV. These results should provide other researchers with the information needed to develop similar diagnostic assays for the study of BoTV.

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The role of serum periostin in the diagnosis of asthma: A meta-analysis

Allergy and Asthma Proceedings ◽

10.2500/aap.2020.41.200038 ◽

2020 ◽

Vol 41 (4) ◽

pp. 240-247

Author(s):

Lei Yang ◽

Qingtao Zhao ◽

Shuyu Wang

Keyword(s):

Diagnostic Accuracy ◽

Meta Analysis ◽

Characteristic Curve ◽

False Negative ◽

Summary Receiver Operating Characteristic ◽

True Negative ◽

Negative Results ◽

Noninvasive Biomarker ◽

Sensitivity Specificity ◽

Serum Periostin

Background: Serum periostin has been proposed as a noninvasive biomarker for asthma diagnosis and management. However, its accuracy for the diagnosis of asthma in different populations is not completely clear. Methods: This meta-analysis aimed to evaluate the diagnostic accuracy of periostin level in the clinical determination of asthma. Several medical literature data bases were searched for relevant studies through December 1, 2019. The numbers of patients with true-positive, false-positive, false-negative, and true-negative results for the periostin level were extracted from each individual study. We assessed the risk of bias by using Quality Assessment of Diagnostic Accuracy Studies 2. We used the meta-analysis to produce summary estimates of accuracy. Results: In total, nine studies with 1757 subjects met the inclusion criteria. The pooled estimates of sensitivity, specificity, and diagnostic odds ratios for the detection of asthma were 0.58 (95% confidence interval [CI], 0.38‐0.76), 0.86 (95% CI, 0.74‐0.93), and 8.28 (95% CI, 3.67‐18.68), respectively. The area under the summary receiver operating characteristic curve was 0.82 (95% CI, 0.79‐0.85). And significant publication bias was found in this meta‐analysis (p = 0.39). Conclusion: Serum periostin may be used for the diagnosis of asthma, with moderate diagnostic accuracy.

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A multicenter, hospital-based and non-inferiority study for diagnostic efficacy of automated whole breast ultrasound for breast cancer in China

Scientific Reports ◽

10.1038/s41598-021-93350-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Yujing Xin ◽

Xinyuan Zhang ◽

Yi Yang ◽

Yi Chen ◽

Yanan Wang ◽

...

Keyword(s):

Breast Cancer ◽

False Negative ◽

Final Analysis ◽

Age Group ◽

Surgical Biopsy ◽

True Negative ◽

Diagnostic Efficacy ◽

Negative Results ◽

Informed Consent Form ◽

Magnetic Resonance Imaging Mri

AbstractThis study is the first multi-center non-inferiority study that aims to critically evaluate the effectiveness of HHUS/ABUS in China breast cancer detection. This was a multicenter hospital-based study. Five hospitals participated in this study. Women (30–69 years old) with defined criteria were invited for breast examination by HHUS, ABUS or/and mammography. For BI-RADS category 3, an additional magnetic resonance imaging (MRI) test was provided to distinguish the true negative results from false negative results. For women classified as BI-RADS category 4 or 5, either core aspiration biopsy or surgical biopsy was done to confirm the diagnosis. Between February 2016 and March 2017, 2844 women signed the informed consent form, and 1947 of them involved in final analysis (680 were 30 to 39 years old, 1267 were 40 to 69 years old).For all participants, ABUS sensitivity (91.81%) compared with HHUS sensitivity (94.70%) with non-inferior Z tests, P = 0.015. In the 40–69 age group, non-inferior Z tests showed that ABUS sensitivity (93.01%) was non-inferior to MG sensitivity (86.02%) with P < 0.001 and HHUS sensitivity (95.44%) was non-inferior to MG sensitivity (86.02%) with P < 0.001. Sensitivity of ABUS and HHUS are all superior to that of MG with P < 0.001 by superior test.For all participants, ABUS specificity (92.89%) was non-inferior to HHUS specificity (89.36%) with P < 0.001. Superiority test show that specificity of ABUS was superior to that of HHUS with P < 0.001. In the 40–69 age group, ABUS specificity (92.86%) was non-inferior to MG specificity (91.68%) with P < 0.001 and HHUS specificity (89.55%) was non-inferior to MG specificity (91.68%) with P < 0.001. ABUS is not superior to MG with P = 0.114 by superior test. The sensitivity of ABUS/HHUS is superior to that of MG. The specificity of ABUS/HHUS is non-inferior to that of MG. In China, for an experienced US radiologist, both HHUS and ABUS have better diagnostic efficacy than MG in symptomatic individuals.

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18F-Fluciclovine Positron Emission Tomography in Prostate Cancer: A Systematic Review and Diagnostic Meta-Analysis

Diagnostics ◽

10.3390/diagnostics11020304 ◽

2021 ◽

Vol 11 (2) ◽

pp. 304

Author(s):

Giuseppina Biscontini ◽

Cinzia Romagnolo ◽

Chiara Cottignoli ◽

Andrea Palucci ◽

Fabio Massimo Fringuelli ◽

...

Keyword(s):

Prostate Cancer ◽

Computed Tomography ◽

Positron Emission Tomography ◽

Meta Analysis ◽

False Negative ◽

Final Analysis ◽

Emission Tomography ◽

True Negative ◽

Positron Emission ◽

Pet Ct

Background: to explore the diagnostic accuracy of 18F-Fluciclovine positron-emission tomography (PET) in prostate cancer (PCa), considering both primary staging prior to radical therapy, biochemical recurrence, and advanced setting. Methods: A systematic web search through Embase and Medline was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Studies performed from 2011 to 2020 were evaluated. The terms used were “PET” or “positron emission tomography” or “positron emission tomography/computed tomography” or “PET/CT” or “positron emission tomography-computed tomography” or “PET-CT” and “Fluciclovine” or “FACBC” and “prostatic neoplasms” or “prostate cancer” or “prostate carcinoma”. Only studies reporting about true positive (TP), true negative (TN), false positive (FP) and false negative (FN) findings of 18F-fluciclovine PET were considered eligible. Results: Fifteen out of 283 studies, and 697 patients, were included in the final analysis. The pooled sensitivity for 18F-Fluciclovine PET/CT for diagnosis of primary PCa was 0.83 (95% CI: 0.80–0.86), the specificity of 0.77 (95% CI: 0.74–0.80). The pooled sensitivity for preoperative LN staging was 0.57 (95% CI: 0.39–0.73) and specificity of 0.99 (95% CI: 0.94–1.00). The pooled sensitivity for the overall detection of recurrence in relapsed patients was 0.68 (95% CI: 0.63–0.73), and specificity of 0.68 (95% CI: 0.60–0.75). Conclusion: This meta-analysis showed promising results in term of sensitivity and specificity for 18F-Fluciclovine PET/CT to stage the primary lesion and in the assessment of nodal metastases, and for the detection of PCa locations in the recurrent setting. However, the limited number of studies and the broad heterogeneity in the selected cohorts and in different investigation protocols are limitation affecting the strength of these results.

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Evaluation of Sandwich Enzyme-Linked Immunosorbent Assay and Reverse Transcription Polymerase Chain Reaction for the Diagnosis of Foot-and-Mouth Disease

Intervirology ◽

10.1159/000517003 ◽

2021 ◽

pp. 1-6

Author(s):

Salman Khan ◽

Syed Asad Ali Shah ◽

Syed Muhammad Jamal

Keyword(s):

Polymerase Chain Reaction ◽

Viral Genome ◽

Foot And Mouth Disease ◽

Enzyme Linked Immunosorbent Assay ◽

Rt Pcr ◽

Chain Reaction ◽

Kappa Value ◽

Polymerase Chain ◽

Pcr Assays ◽

Level Of Agreement

Background: Foot-and-mouth disease (FMD) is an infectious and highly contagious disease of cloven-hoofed domestic and wild animals, causing heavy economic losses to the livestock industry. Rapid and reliable diagnosis of the disease is essential for the implementation of effective control measures. This study compared sandwich enzyme-linked immunosorbent assay (S-ELISA) and conventional reverse transcription polymerase chain reaction (RT-PCR) for the diagnosis of FMD. Methods: A total of 60 epithelial samples from suspected cases of FMD were tested using both S-ELISA and RT-PCR assays. The level of agreement between the assays was assessed by calculating the Kappa value. Results: S-ELISA detected 38 (63%) samples positive for FMD virus (FMDV). Being predominant, serotype O was detected in 22 (57.9%) of the total samples tested positive, whereas 9 (23.7%) and 7 (18.4%) samples were found positive for serotypes A and Asia-1, respectively. RT-PCR detected viral genome in 51 (85%) of the samples using pan-FMDV primers set, 1F/1R. Thirty-six samples were found positive and 7 negative by both the tests. The level of agreement between the tests was assessed by calculating the Kappa value, which was found to be fair (Kappa value = 0.303 and 95% CI = 0.089; 0.517) and significant (p = 0.009). However, 2 samples, which were found positive on S-ELISA tested negative on RT-PCR. This may be attributed to the presence of nucleotide mismatch(es) in the primer-binding sites that may have resulted in failure of amplification of the viral genome. The serotype-specific RT-PCR assays not only confirmed serotyping results of S-ELISA but were also able to establish serotype in 9 S-ELISA-negative but pan-FMDV RT-PCR-positive samples. Conclusions: The RT-PCR assay contributes significantly to establishing a quick, sensitive, and definitive diagnosis of FMD in resource-constrained countries. Samples giving negative results in S-ELISA should be tested in RT-PCR for the disease detection and virus typing.

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Can artificial intelligence reduce the interval cancer rate in mammography screening?

European Radiology ◽

10.1007/s00330-021-07686-3 ◽

2021 ◽

Author(s):

Kristina Lång ◽

Solveig Hofvind ◽

Alejandro Rodríguez-Ruiz ◽

Ingvar Andersson

Keyword(s):

Artificial Intelligence ◽

Risk Score ◽

Mammography Screening ◽

False Negative ◽

Interval Cancer ◽

Stage Iv ◽

True Negative ◽

Stage Iv Disease ◽

Interval Cancer Rate ◽

Screening Mammograms

Abstract Objectives To investigate whether artificial intelligence (AI) can reduce interval cancer in mammography screening. Materials and methods Preceding screening mammograms of 429 consecutive women diagnosed with interval cancer in Southern Sweden between 2013 and 2017 were analysed with a deep learning–based AI system. The system assigns a risk score from 1 to 10. Two experienced breast radiologists reviewed and classified the cases in consensus as true negative, minimal signs or false negative and assessed whether the AI system correctly localised the cancer. The potential reduction of interval cancer was calculated at different risk score thresholds corresponding to approximately 10%, 4% and 1% recall rates. Results A statistically significant correlation between interval cancer classification groups and AI risk score was observed (p < .0001). AI scored one in three (143/429) interval cancer with risk score 10, of which 67% (96/143) were either classified as minimal signs or false negative. Of these, 58% (83/143) were correctly located by AI, and could therefore potentially be detected at screening with the aid of AI, resulting in a 19.3% (95% CI 15.9–23.4) reduction of interval cancer. At 4% and 1% recall thresholds, the reduction of interval cancer was 11.2% (95% CI 8.5–14.5) and 4.7% (95% CI 3.0–7.1). The corresponding reduction of interval cancer with grave outcome (women who died or with stage IV disease) at risk score 10 was 23% (8/35; 95% CI 12–39). Conclusion The use of AI in screen reading has the potential to reduce the rate of interval cancer without supplementary screening modalities. Key Points • Retrospective study showed that AI detected 19% of interval cancer at the preceding screening exam that in addition showed at least minimal signs of malignancy. Importantly, these were correctly localised by AI, thus obviating supplementary screening modalities. • AI could potentially reduce a proportion of particularly aggressive interval cancers. • There was a correlation between AI risk score and interval cancer classified as true negative, minimal signs or false negative.

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Optimal Preventive Maintenance of Wind Turbine Components with Imperfect Continuous Condition Monitoring

Energies ◽

10.3390/en12193801 ◽

2019 ◽

Vol 12 (19) ◽

pp. 3801 ◽

Cited By ~ 2

Author(s):

Ahmed Raza ◽

Vladimir Ulansky

Keyword(s):

Wind Turbine ◽

Condition Monitoring ◽

Preventive Maintenance ◽

False Negative ◽

Maintenance Cost ◽

Arbitrary Distribution ◽

Average Lifetime ◽

True Negative ◽

Degradation Failure ◽

Lifetime Maintenance

Among the different maintenance techniques applied to wind turbine (WT) components, online condition monitoring is probably the most promising technique. The maintenance models based on online condition monitoring have been examined in many studies. However, no study has considered preventive maintenance models with incorporated probabilities of correct and incorrect decisions made during continuous condition monitoring. This article presents a mathematical model of preventive maintenance, with imperfect continuous condition monitoring of the WT components. For the first time, the article introduces generalized expressions for calculating the interval probabilities of false positive, true positive, false negative, and true negative when continuously monitoring the condition of a WT component. Mathematical equations that allow for calculating the expected cost of maintenance per unit of time and the average lifetime maintenance cost are derived for an arbitrary distribution of time to degradation failure. A numerical example of WT blades maintenance illustrates that preventive maintenance with online condition monitoring reduces the average lifetime maintenance cost by 11.8 times, as compared to corrective maintenance, and by at least 4.2 and 2.6 times, compared with predetermined preventive maintenance for low and high crack initiation rates, respectively.

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