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1.
Biosensors (Basel) ; 11(6)2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34073756

RESUMO

Despite collaborative efforts from all countries, coronavirus disease 2019 (COVID-19) pandemic has been continuing to spread globally, forcing the world into social distancing period, making a special challenge for public healthcare system. Before vaccine widely available, the best approach to manage severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is to achieve highest diagnostic accuracy by improving biosensor efficacy. For SARS-CoV-2 diagnostics, intensive attempts have been made by many scientists to ameliorate the drawback of current biosensors of SARS-CoV-2 in clinical diagnosis to offer benefits related to platform proposal, systematic analytical methods, system combination, and miniaturization. This review assesses ongoing research efforts aimed at developing integrated diagnostic tools to detect RNA viruses and their biomarkers for clinical diagnostics of SARS-CoV-2 infection and further highlights promising technology for SARS-CoV-2 specific diagnosis. The comparisons of SARS-CoV-2 biomarkers as well as their applicable biosensors in the field of clinical diagnosis were summarized to give scientists an advantage to develop superior diagnostic platforms. Furthermore, this review describes the prospects for this rapidly growing field of diagnostic research, raising further interest in analytical technology and strategic plan for future pandemics.


Assuntos
Técnicas Biossensoriais/instrumentação , Teste para COVID-19/instrumentação , SARS-CoV-2/isolamento & purificação , Animais , Técnicas Biossensoriais/métodos , Teste para COVID-19/métodos , Colorimetria/instrumentação , Colorimetria/métodos , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Ensaio de Imunoadsorção Enzimática/instrumentação , Ensaio de Imunoadsorção Enzimática/métodos , Desenho de Equipamento , Humanos , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Técnicas de Amplificação de Ácido Nucleico/métodos , Testes Imediatos
2.
BMC Infect Dis ; 21(1): 487, 2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34044776

RESUMO

BACKGROUND: The World Health Organization (WHO) has targeted a reduction in viral hepatitis-related mortality by 65% and incidence by 90% by 2030, necessitating enhanced hepatitis B treatment and prevention programmes in low- and middle-income countries. Hepatitis B e antigen (HBeAg) status is used in the assessment of eligibility for antiviral treatment and for prevention of mother-to-child transmission (PMTCT). Accordingly, the WHO has classified HBeAg rapid diagnostic tests (RDTs) as essential medical devices. METHODS: We assessed the performance characteristics of three commercially available HBeAg RDTs (SD Bioline, Alere, South Africa; Creative Diagnostics, USA; and Biopanda Reagents, UK) in two hepatitis B surface antigen-positive cohorts in Blantyre, Malawi: participants of a community study (n = 100) and hospitalised patients with cirrhosis or hepatocellular carcinoma (n = 94). Two investigators, blinded to the reference test result, independently assessed each assay. We used an enzyme-linked immunoassay (Monolisa HBeAg, Bio-Rad, France) as a reference test and quantified HBeAg concentration using dilutions of the WHO HBeAg standard. We related the findings to HBV DNA levels, and evaluated treatment eligibility using the TREAT-B score. RESULTS: Among 194 HBsAg positive patients, median age was 37 years, 42% were femaleand 26% were HIV co-infected. HBeAg prevalence was 47/194 (24%). The three RDTs showed diagnostic sensitivity of 28% (95% CI 16-43), 53% (38-68) and 72% (57-84) and specificity of 96-100% for detection of HBeAg. Overall inter-rater agreement κ statistic was high at 0.9-1.0. Sensitivity for identifying patients at the threshold where antiviral treatment is recommended for PMTCT, with HBV DNA > 200,000 IU/ml (39/194; 20%), was 22, 49 and 54% respectively. Using the RDTs in place of the reference HBeAg assay resulted in 3/43 (9%), 5/43 (12%) and 8/43 (19%) of patients meeting the TREAT-B treatment criteria being misclassified as ineligible for treatment. A relationship between HBeAg concentration and HBeAg detection by RDT was observed. A minimum HBeAg concentration of 2.2-3.1 log10IU/ml was required to yield a reactive RDT. CONCLUSIONS: Commercially available HBeAg RDTs lack sufficient sensitivity to accurately classify hepatitis B patients in Malawi. This has implications for hepatitis B public health programs in sub-Saharan Africa. Alternative diagnostic assays are recommended.


Assuntos
Testes Diagnósticos de Rotina/métodos , Antígenos E da Hepatite B/sangue , Vírus da Hepatite B/imunologia , Hepatite B/diagnóstico , Adulto , Antivirais/uso terapêutico , Coinfecção/virologia , DNA Viral/análise , Ensaio de Imunoadsorção Enzimática/métodos , Infecções por HIV/complicações , Hepatite B/complicações , Antígenos de Superfície da Hepatite B/análise , Vírus da Hepatite B/isolamento & purificação , Humanos , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Malaui , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Testes Sorológicos
3.
Viruses ; 13(5)2021 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-33946860

RESUMO

Antigen tests for SARS-CoV-2 diagnosis are simpler and faster than their molecular counterparts. Clinical validation of such tests is a prerequisite before their field applications. We developed and clinically evaluated an immunochromatographic immunoassay, GenBody™ COVAG025, for the rapid detection of SARS-CoV-2 nucleocapsid (NP) antigen in two different clinical studies. Retrospectively, 130 residual nasopharyngeal swabs transferred in viral transport medium (VTM), pre-examined for COVID-19 through emergency use authorization (EUA)-approved real-time RT-PCR assay and tested with GenBody™ COVAG025, revealed a sensitivity and specificity of 90.00% (27/30; 95% CI: 73.47% to 97.89%) and 98.00% (98/100; 95% CI: 92.96% to 99.76%), respectively, fulfilling WHO guidelines. Subsequently, the prospective examination of 200 symptomatic and asymptomatic nasopharyngeal swabs, collected on site and tested with GenBody™ COVAG025 and EUA-approved real-time RT-PCR assay simultaneously, revealed a significantly higher sensitivity and specificity of 94.00% (94/100; 95% CI: 87.40% to 97.77%) and 100.00% (100/100; 95% CI: 96.38% to 100.00%), respectively. Clinical sensitivity and specificity were significantly high for samples with Ct values ≤ 30 as well as within 3 days of symptom onset, justifying its dependency on the viral load. Thus, it is assumed this can help with the accurate diagnosis and timely isolation and treatment of patients with COVID-19, contributing to better control of the global pandemic.


Assuntos
Teste Sorológico para COVID-19/métodos , COVID-19/diagnóstico , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Nasofaringe/virologia , SARS-CoV-2/isolamento & purificação , Testes Diagnósticos de Rotina , Humanos , Índia/epidemiologia , Fosfoproteínas/imunologia , Estudos Prospectivos , República da Coreia/epidemiologia , Estudos Retrospectivos , Sensibilidade e Especificidade
4.
BMC Infect Dis ; 21(1): 478, 2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34039287

RESUMO

BACKGROUND: Healthcare workers (HCWs) are at high risk of exposure to SARS-CoV-2. Cross-sectional studies have provided variable rates of seroprevalence in HCWs. Longitudinal assessments of the serological response to Covid-19 among HCWs are crucial to understanding the risk of infection and changes in antibody titers over time. We aimed to investigate seroprevalence and risk factors associated with seroconversion in a prospective cohort of HCWs during the peak of the first wave of the Covid-19 pandemic. METHODS: We conducted a longitudinal study among 446 front-line HCWsin a tertiary-care hospital in Chile from April to July 2020. IgG was determined monthly using two different ELISAs in serum samples of HCWs, during the three-month period. In each visit, demographic data, symptoms, risk factors, and exposure risks were also assessed. RESULTS: The overall seroprevalence at the end of the study period was 24% (95% CI20.2-28.3), with 43% of seropositive HCWs reporting no prior symptoms. Seroconversion rates significantly differed over the study period, from 2.1% to as high as 8.8% at the peak of the epidemic. There were no statistically significant differences observed between HCWs in direct clinical care of patients with Covid-19 and those working in low risk areas. Antibody titers appeared to wane over time. CONCLUSIONS: HCWs were severely affected with a high rate of seroconversion that appeared to mirror the local epidemiological situation. A significant amount of participants underwent an asymptomatic infection, highlighting the need for improved surveillance policies. Antibody titers appear to wane over time; further studies to understand this finding's impact on the risk of reinfection are warranted.


Assuntos
Anticorpos Antivirais/sangue , Teste Sorológico para COVID-19 , COVID-19/imunologia , Pessoal de Saúde/estatística & dados numéricos , Imunoglobulina G/sangue , SARS-CoV-2/imunologia , Soroconversão , Adulto , Idoso , COVID-19/diagnóstico , COVID-19/epidemiologia , Chile/epidemiologia , Estudos de Coortes , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Soroepidemiológicos , Centros de Atenção Terciária
5.
Clin Interv Aging ; 16: 749-755, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33958861

RESUMO

Purpose: Among other emerging amyloid-targeting blood-based biomarkers, Multimer Detection System-Oligomeric Amyloid-ß (MDS-OAß) measures dynamic changes in concentration of oligomeric amyloid-ß (OAß), which is considered the main pathogenic culprit of Alzheimer's disease (AD), in plasma after spiking with synthetic amyloid-ß (Aß). We aimed to investigate the predictability of MDS-OAß on amyloid positron emission tomography (PET) positivity. Patients and Methods: A total of 96 subjects who visited Seoul National University Bundang Hospital for medical check-up complaining of cognitive decline and had undergone extensive medical assessment were recruited. Amyloid statuses were dichotomized into positive or negative based on visual assessment of amyloid PET. Plasma OAß concentration was measured by MDS-OAß. In the previous validation study, 0.78ng/mL was established as the cut-off value and the plasma OAß concentration higher than or equal to the cut-off value was defined as MDS-OAß positive. Results: MDS-OAß positivity could discriminate amyloid PET positivity with the AUC value of 0.855 (95% CI 0.776-0.933). Adding MDS-OAß positivity to prediction models including age, MMSE score, and APOE ε4 status improved performance up to the AUC value of 0.926 (95% CI 0.871-0.980). Conclusion: The Aß oligomerization tendency in plasma could predict amyloid PET positivity with high performance, and, when it is combined with age, MMSE score, and APOE ε4 status, predictability was improved substantially. This suggests the potential of MDS-OAß as a useful initial stage test in the clinical and research fields of AD.


Assuntos
Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Tomografia por Emissão de Pósitrons/métodos , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/sangue , Doença de Alzheimer/líquido cefalorraquidiano , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Apolipoproteínas E/genética , Biomarcadores , Disfunção Cognitiva/diagnóstico , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
6.
Am J Clin Pathol ; 155(6): 773-775, 2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-33899091

RESUMO

OBJECTIVES: Serologic assay performance studies for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-​2) in pediatric populations are lacking, and few seroprevalence studies have routinely incorporated orthogonal testing to improve accuracy. METHODS: Remnant serum samples for routine bloodwork from 2,338 pediatric patients at UPMC Children's Hospital of Pittsburgh were assessed using the EUROIMMUN Anti-SARS-CoV-2 ELISA IgG (EuroIGG) assay. Reactive cases with sufficient volume were also tested using 3 additional commercial assays. RESULTS: Eighty-five specimens were reactive according to the EuroIGG, yielding 3.64% (95% confidence interval [CI], 2.91%-4.48%) seropositivity, of which 73 specimens had sufficient remaining volume for confirmation by orthogonal testing. Overall, 19.18% (95% CI, 10.18%-28.18%) of samples were positive on a second and/or third orthogonal assay. This 80.82% false positivity rate is disproportionate to the expected false positivity rate of 50% given our pediatric population prevalence and assay performance. CONCLUSIONS: In pediatric populations, false-positive SARS-CoV-2 serology may be more common than assay and prevalence parameters would predict, and further studies are needed to establish the performance of SARS-CoV-2 serology in children.


Assuntos
Teste para COVID-19 , COVID-19/diagnóstico , SARS-CoV-2/patogenicidade , Sensibilidade e Especificidade , Estudos Soroepidemiológicos , Anticorpos Antivirais/sangue , Teste para COVID-19/métodos , Criança , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Imunoglobulina A/análise , Masculino
7.
Viruses ; 13(4)2021 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-33916759

RESUMO

Cats are susceptible to infection with severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2). Whilst a number of studies have been performed worldwide on owned cats, limited data are available on stray, colony or shelter cats. We investigated SARS-CoV-2 infection in a stray cat population before and during human outbreaks of SARS-CoV-2 in cities in the Lombardy region in northern Italy, a high endemic region for SARS-CoV-2, using serological and molecular methods. A cohort of different samples were collected from 241 cats, including frozen archived serum samples from 136 cats collected before the 2019 coronavirus disease (COVID-19) pandemic and serum, pharyngeal and rectal swab samples from 105 cats collected during the SARS-CoV-2 outbreak. All pre-pandemic samples tested seronegative for antibodies against the nucleocapsid of SARS-CoV-2 using indirect enzyme linked immunosorbent assay (ELISA) test, while one serum sample collected during the pandemic was seropositive. No serological cross-reactivity was detected between SARS-CoV-2 antibodies and antibodies against feline enteric (FECV) and infectious peritonitis coronavirus (FIPC), Feline Immunodeficiency Virus (FIV), Feline Calicivirus (FCV), Feline Herpesvirus-1 (FHV-1), Feline Parvovirus (FPV), Leishmania infantum, Anaplasma phagocytophilum, Rickettsia spp., Toxoplasma gondii or Chlamydophila felis. No pharyngeal or rectal swab tested positive for SARS-CoV-2 RNA on real time reverse transcription-polymerase chain reaction (rRT-PCR). Our data show that SARS-CoV-2 did infect stray cats in Lombardy during the COVID-19 pandemic, but with lower prevalence than found in owned cats. This should alleviate public concerns about stray cats acting as SARS-CoV-2 carriers.


Assuntos
COVID-19/epidemiologia , Doenças do Gato/epidemiologia , Pandemias , Anaplasma phagocytophilum , Animais , Anticorpos Antivirais/sangue , Teste de Ácido Nucleico para COVID-19 , Infecções por Caliciviridae/epidemiologia , Calicivirus Felino/imunologia , Gatos , Chlamydia , Ensaio de Imunoadsorção Enzimática/métodos , Panleucopenia Felina/epidemiologia , Vírus da Panleucopenia Felina/imunologia , Humanos , Itália/epidemiologia , Leishmania infantum , Masculino , Prevalência , Rickettsia , SARS-CoV-2
8.
Food Chem ; 355: 129633, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33819808

RESUMO

In the presented study, a horseradish peroxidase (HRP)-mediated ratiometric fluorescence enzyme-linked immunosorbent assay (ELISA) for zearalenone (ZEN) was reported based on fluorescence quenching of gold-silver bimetallic nanoclusters (Au-Ag NCs). HRP-antibody was used as a bridge in this immunoassay, linking the ratiometric fluorescence signal to the ZEN concentration. HRP catalyzed the oxidization of o-phenylenediamine in the presence of H2O2, leading to the formation of 2,3-diaminophenazine, which not only delivered a new peak at 580 nm but also quenched Au-Ag NCs fluorescence at 690 nm. Under optimal conditions, the detection limit for the proposed ELISA was 0.017 ng/mL, which was approximately 6.6-fold lower than conventional ELISA. Moreover, analytical performances were evaluated fully including specificity, accuracy, precision, and practicability, and showed that this method provides a potential platform for sensitive and reliable detection of ZEN.


Assuntos
Ensaio de Imunoadsorção Enzimática/métodos , Ouro/química , Peroxidase do Rábano Silvestre/metabolismo , Nanopartículas Metálicas/química , Prata/química , Zearalenona/análise , Fluorescência , Peróxido de Hidrogênio/química , Nanopartículas Metálicas/ultraestrutura , Espectrometria de Fluorescência/métodos
9.
BMC Infect Dis ; 21(1): 336, 2021 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-33838648

RESUMO

BACKGROUND: Tuberculosis (TB) is a serious infectious disease caused by Mycobacterium tuberculosis (MTB). An estimated 1.7 billion people worldwide are infected with Mycobacterium tuberculosis (LTBI) during the incubation period without any obvious symptoms. Because of MTB's high infection and mortality rates, there is an urgent need to develop a fast, portable, and sensitive diagnostic technology for its detection. METHODS: We included research from PubMed, Cochrane Library, Web of Science, and Embase and extracted the data. MetaDisc and STATA were used to build forest plots, Deek's funnel plot, Fagan plot, and bivariate boxplot for analysis. RESULTS: Forty-six articles were analyzed, the results of which are as follows: sensitivity and specificity were 0.92 (0.91-0.93) and 0.95 (0.94-0.95) respectively. The NLR and PLR were 0.04 (95% CI 0.03-0.07) and 25.32 (95% CI 12.38-51.78) respectively. DOR was 639.60 (243.04-1683.18). The area under the SROC curve (AUC) was 0.99. CONCLUSIONS: MPT64 exhibits good diagnostic efficiency for MTB. There is no obvious heterogeneity between the three commercial kits.


Assuntos
Antígenos de Bactérias/imunologia , Mycobacterium tuberculosis , Kit de Reagentes para Diagnóstico , Tuberculose/microbiologia , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Imunoensaio/métodos , Mycobacterium tuberculosis/isolamento & purificação , Sensibilidade e Especificidade , Tuberculose/diagnóstico
10.
mSphere ; 6(2)2021 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-33883259

RESUMO

The coronavirus disease 2019 (COVID-19) global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to place an immense burden on societies and health care systems. A key component of COVID-19 control efforts is serological testing to determine the community prevalence of SARS-CoV-2 exposure and quantify individual immune responses to prior SARS-CoV-2 infection or vaccination. Here, we describe a laboratory-developed antibody test that uses readily available research-grade reagents to detect SARS-CoV-2 exposure in patient blood samples with high sensitivity and specificity. We further show that this sensitive test affords the estimation of viral spike-specific IgG titers from a single sample measurement, thereby providing a simple and scalable method to measure the strength of an individual's immune response. The accuracy, adaptability, and cost-effectiveness of this test make it an excellent option for clinical deployment in the ongoing COVID-19 pandemic.IMPORTANCE Serological surveillance has become an important public health tool during the COVID-19 pandemic. Detection of protective antibodies and seroconversion after SARS-CoV-2 infection or vaccination can help guide patient care plans and public health policies. Serology tests can detect antibodies against past infections; consequently, they can help overcome the shortcomings of molecular tests, which can detect only active infections. This is important, especially when considering that many COVID-19 patients are asymptomatic. In this study, we describe an enzyme-linked immunosorbent assay (ELISA)-based qualitative and quantitative serology test developed to measure IgG and IgA antibodies against the SARS-CoV-2 spike glycoprotein. The test can be deployed using commonly available laboratory reagents and equipment and displays high specificity and sensitivity. Furthermore, we demonstrate that IgG titers in patient samples can be estimated from a single measurement, enabling the assay's use in high-throughput clinical environments.


Assuntos
Anticorpos Antivirais/sangue , Teste Sorológico para COVID-19/métodos , COVID-19/diagnóstico , COVID-19/imunologia , SARS-CoV-2/imunologia , Adolescente , Adulto , Idoso , Especificidade de Anticorpos , COVID-19/epidemiologia , Teste Sorológico para COVID-19/estatística & dados numéricos , Estudos de Casos e Controles , Estudos de Coortes , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/estatística & dados numéricos , Monitoramento Epidemiológico , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Pandemias , Estudos Soroepidemiológicos , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto Jovem
11.
Res Vet Sci ; 136: 527-534, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33882381

RESUMO

Oxytocin is currently of high interest as a biomarker of welfare and stress in humans and animals. The purpose of this study was to validate two new assays (one using a monoclonal antibody and the other using a polyclonal antibody) for the oxytocin measurement in the saliva of dogs. For this purpose, an analytical validation was performed, and these assays were applied in an experimental trial in which dogs were stroked by their owners. In the experimental trial, saliva samples of 17 dogs were collected by the owners at three different times: a basal sample, at the end of 10 min of an affiliative interaction with their owners consisting of stroking and 15 min after the end of the affiliative interaction. The dogs were separated into two groups (group 1, n = 8 and group 2, n = 9) according to the acceptance of the sponge and the response to the stroking. Significant differences in the response of salivary oxytocin after stroking in the two groups were found when the assay with the monoclonal antibody was used. This assay showed a significant increase just after the end of affiliative interaction (P < 0.01) and 15 min after (P < 0.01) in those dogs that had a good acceptance of the sponge and the stroking induced a positive response on them (based in a Likert-type scale from 1 to 10). These data reflect that the assays used in this study can lead to different results when quantifying oxytocin in the saliva of dogs after stroking.


Assuntos
Cães/fisiologia , Ensaio de Imunoadsorção Enzimática/veterinária , Ocitocina/análise , Animais de Estimação/fisiologia , Saliva/química , Animais , Anticorpos/imunologia , Anticorpos Monoclonais/imunologia , Biomarcadores , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Masculino
12.
PLoS One ; 16(4): e0250319, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33909646

RESUMO

Projections of the stage of the Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) pandemic and local, regional and national public health policies to limit coronavirus spread as well as "reopen" cities and states, are best informed by serum neutralizing antibody titers measured by reproducible, high throughput, and statically credible antibody (Ab) assays. To date, a myriad of Ab tests, both available and FDA authorized for emergency, has led to confusion rather than insight per se. The present study reports the results of a rapid, point-in-time 1,000-person cohort study using serial blood donors in the New York City metropolitan area (NYC) using multiple serological tests, including enzyme-linked immunosorbent assays (ELISAs) and high throughput serological assays (HTSAs). These were then tested and associated with assays for neutralizing Ab (NAb). Of the 1,000 NYC blood donor samples in late June and early July 2020, 12.1% and 10.9% were seropositive using the Ortho Total Ig and the Abbott IgG HTSA assays, respectively. These serological assays correlated with neutralization activity specific to SARS-CoV-2. The data reported herein suggest that seroconversion in this population occurred in approximately 1 in 8 blood donors from the beginning of the pandemic in NYC (considered March 1, 2020). These findings deviate with an earlier seroprevalence study in NYC showing 13.7% positivity. Collectively however, these data demonstrate that a low number of individuals have serologic evidence of infection during this "first wave" and suggest that the notion of "herd immunity" at rates of ~60% or higher are not near. Furthermore, the data presented herein show that the nature of the Ab-based immunity is not invariably associated with the development of NAb. While the blood donor population may not mimic precisely the NYC population as a whole, rapid assessment of seroprevalence in this cohort and serial reassessment could aid public health decision making.


Assuntos
COVID-19/epidemiologia , SARS-CoV-2/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/imunologia , Doadores de Sangue , COVID-19/imunologia , Estudos de Coortes , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Cidade de Nova Iorque/epidemiologia , SARS-CoV-2/patogenicidade , Sensibilidade e Especificidade , Soroconversão/fisiologia , Estudos Soroepidemiológicos , Testes Sorológicos/métodos , Glicoproteína da Espícula de Coronavírus/imunologia
13.
Vaccimonitor (La Habana, Print) ; 30(1)ene.-abr. 2021. tab
Artigo em Inglês | LILACS, CUMED | ID: biblio-1150246

RESUMO

Foot and mouth disease is a highly contagious viral disease of cloven-hoofed animals that has a significant economic impact on livestock. A recent outbreak was detected and recorded as exotic strain of foot and mouth disease virus SAT2 (Serotype SAT2, topotype VII, Lib-12 lineage). The emergency vaccine was produced and assessed in vivo and large number of vaccine batches were urgently needed. The present work was aimed to provide a rapid evaluation of inactivated foot and mouth disease SAT2 oily vaccine to exclude the unsatisfactory batches during emergency circumstances and to reduce time, effort and cost. The extraction of foot and mouth disease antigen content from oily adjuvanted vaccine was carried out using isopropyl myristate and benzyl alcohol methods. The extracted viral antigen was identified by foot and mouse disease serotyping ELISA and 146S content was quantified using sucrose density gradient analysis. Evaluations were carried out instantly and at 2h, 6h and 24h. The results indicated the efficiency of benzyl alcohol to breakdown the oil emulsion either MONTANIDE™ ISA 206 VG or MONTANIDE™ ISA 50 V2, while the isopropyl myristate was efficient for MONTANIDE™ ISA 50 V2 only. The identification and quantification of 146S for extracted antigen using benzyl alcohol indicated significant stable records at different time intervals for the vaccine batches, while the extraction using isopropyl myristate indicated unstable records at different time intervals. It was concluded that the evaluation of monovalent foot and mouse disease vaccine could be conducted in vitro, using serotyping ELISA and quantification of 146S for the extracted antigen, either using benzyl alcohol or isopropyl myristate (MONTANIDE™ ISA50 V2 only), with the consideration that 146S content should not less than 4 μg/mL(AU)


La fiebre aftosa es una enfermedad viral altamente contagiosa de los animales de pezuña hendida que tiene un impacto económico significativo en el ganado. Se detectó un brote reciente que se registró como causado por una cepa exótica del virus de la fiebre aftosa (serotipo SAT2, topotipo VII, linaje Lib-12). La vacuna de emergencia se elaboró y evaluó in vivo, existiendo una urgente necesidad de contar con un gran número de lotes de la misma. El presente trabajo tuvo como objetivo proporcionar una evaluación rápida de la vacuna oleosa inactivada (SAT2) contra la fiebre aftosa, para excluir los lotes insatisfactorios durante circunstancias de emergencia, reduciendo tiempo, esfuerzo y costo. La extracción del contenido de antígeno de fiebre aftosa, de la vacuna oleosa adyuvada, se llevó a cabo utilizando miristato de isopropilo y alcohol bencílico. El antígeno viral extraído se identificó utilizando un ELISA de serotipificación y se cuantificó el contenido de 146S mediante análisis de gradiente de densidad de sacarosa. Las evaluaciones se realizaron de forma instantánea y a las 2h, 6h y 24h. Los resultados indicaron la eficacia del alcohol bencílico para separar la emulsión de aceite para MONTANIDE ™ ISA 206 VG o MONTANIDE™ ISA 50 V2, mientras que el miristato de isopropilo fue eficaz para MONTANIDE™ ISA 50 V2 únicamente(AU)


Assuntos
Animais , Febre Aftosa , Ensaio de Imunoadsorção Enzimática/métodos , Vacinas
14.
Sci Rep ; 11(1): 7754, 2021 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-33833246

RESUMO

Serological testing is emerging as a powerful tool to progress our understanding of COVID-19 exposure, transmission and immune response. Large-scale testing is limited by the need for in-person blood collection by staff trained in venepuncture, and the limited sensitivity of lateral flow tests. Capillary blood self-sampling and postage to laboratories for analysis could provide a reliable alternative. Two-hundred and nine matched venous and capillary blood samples were obtained from thirty nine participants and analysed using a COVID-19 IgG ELISA to detect antibodies against SARS-CoV-2. Thirty eight out of thirty nine participants were able to self-collect an adequate sample of capillary blood (≥ 50 µl). Using plasma from venous blood collected in lithium heparin as the reference standard, matched capillary blood samples, collected in lithium heparin-treated tubes and on filter paper as dried blood spots, achieved a Cohen's kappa coefficient of > 0.88 (near-perfect agreement, 95% CI 0.738-1.000). Storage of capillary blood at room temperature for up to 7 days post sampling did not affect concordance. Our results indicate that capillary blood self-sampling is a reliable and feasible alternative to venepuncture for serological assessment in COVID-19.


Assuntos
Coleta de Amostras Sanguíneas/métodos , Teste Sorológico para COVID-19/métodos , COVID-19/diagnóstico , SARS-CoV-2/isolamento & purificação , Adulto , COVID-19/sangue , Teste em Amostras de Sangue Seco/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
15.
J Virol Methods ; 292: 114122, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33705832

RESUMO

INTRODUCTION: Reliable methods for the detection of SARS-CoV-2 neutralising antibodies (NAbs) are essential for the evaluation of vaccine candidates and for the selection of convalescent plasma donors. Virus neutralisation tests (NTs) are the gold standard for the detection and quantification of NAbs, but they are complex and require BSL3 facilities. In contrast, surrogate enzyme-linked immunosorbent assays (sELISA) offer the possibility of high-throughput testing under standard laboratory safety conditions. In this study, we investigated two commercial sELISA kits (GenScript, AdipoGen) designed for the detection of SARS-CoV-2 NAbs. METHODS: 276 plasma samples were screened using commercial IgG-ELISA and NAbs titres were determined by micro-neutralisation test (micro-NT). In addition, all samples were tested in both sELISA. Sensitivity and specificity for both sELISA were determined in comparison to the micro-NT results. RESULTS: 57 % of the samples were SARS-CoV-2 NAb positive in micro-NT, while 43 % tested negative. Comparison with micro-NT results showed a sensitivity of 98.2 % and a specificity of 69.5 % for the GenScript ELISA. The AdipoGen ELISA had a sensitivity of 83.5 % and a specificity of 97.8 %. False negative results were obtained mainly on samples with low NAbs titres. CONCLUSION: Both sELISA were able to qualitatively detect NAbs in plasma samples. Sensitivity and specificity differed between sELISA with GenScript superior in sensitivity and AdipoGen superior in specificity. Both sELISA were unable to quantify NAbs, thus neither of them can completely replace conventional NTs. However, in a two-step diagnostic algorithm, AdipoGen could potentially replace NT as a subsequent confirmatory test due to its high specificity but only in settings where no exact NAbs quantification is needed.


Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Teste Sorológico para COVID-19/métodos , COVID-19/diagnóstico , Ensaio de Imunoadsorção Enzimática/métodos , SARS-CoV-2/imunologia , Humanos , Imunoglobulina G/sangue , Testes de Neutralização
16.
J Virol Methods ; 292: 114141, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33753172

RESUMO

In this study, we developed and evaluated a luciferase immunosorbent assay (LISA) for quantitative detection of IgG antibody against SARS-CoV-2 nucleoprotein (NP). Anti-SARS-CoV-2 NP antibody in serum or plasma samples was captured by protein G-coated microtiter plate and detected using the crude cell lysates expressing Nanoluc luciferase (Nluc) enzyme fused with SARS-CoV-2 NP. After the addition of furimazine substrate, the levels of anti-SARS-CoV-2 NP IgG antibody were quantitatively measured as luciferase light units. As expected, SARS-CoV-2 NP showed cross-reactivity with the monoclonal antibodies against SARS-CoV NP, but not MERS-CoV NP-specific monoclonal antibodies or the monoclonal antibodies against SARS-CoV Spike protein. LISA for detecting murine monoclonal antibody against SARS-CoV NP showed a low limit of detection of 0.4 pg/µl and linear detection range from 0.4 pg/µl to 75 pg/µl. Furthermore, LISA had a sensitivity of 71 % when testing COVID-19 patients at the second week post onset and a specificity of 100 % when testing healthy blood donors.


Assuntos
Anticorpos Antivirais/sangue , COVID-19/diagnóstico , Ensaio de Imunoadsorção Enzimática/métodos , Imunoglobulina G/sangue , Proteínas do Nucleocapsídeo/imunologia , SARS-CoV-2/imunologia , Anticorpos Monoclonais/imunologia , Reações Cruzadas , Humanos , Luciferases
17.
Yakugaku Zasshi ; 141(3): 427-431, 2021.
Artigo em Japonês | MEDLINE | ID: mdl-33642512

RESUMO

Daptomycin (DAP) has a completely different mechanism of action compared with conventional drugs for methicillin-resistant Staphylococcus aureus (MRSA) and is widely used as the first-line drug for treatment of dermal soft tissue infection and sepsis caused by MRSA infection in clinical practice. However, DAP has serious side effects, including renal dysfunction and rhabdomyolysis, and thus therapeutic drug monitoring of DAP is recommended. The purpose of this study was to develop an enzyme-linked immunosorbent assay (ELISA) for DAP that is simpler and more sensitive compared with existing assay methods and can be used in pharmacokinetic studies. Anti-DAP antibody was obtained by immunizing mice with an antigen conjugated with mercaptosuccinyl bovine serum albumin using N-(4-maleimidobutyryloxy) succinimide as a heterobifunctional coupling agent. Enzyme labeling of DAP with horseradish peroxidase was performed using pyromellitic dianhydride. The generated antibody and enzyme conjugate were used to develop a highly sensitive and specific ELISA for DAP in human serum. This ELISA shows a linear range of detection from 0.3 to 72.9 ng/mL, and a limit of quantification of approximately 0.3 ng/mL. The developed ELISA should be a valuable tool for pharmacokinetic studies and therapeutic drug monitoring of DAP.


Assuntos
Antibacterianos/análise , Daptomicina/análise , Monitoramento de Medicamentos/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Animais , Antibacterianos/efeitos adversos , Antibacterianos/farmacocinética , Daptomicina/efeitos adversos , Daptomicina/farmacocinética , Humanos , Staphylococcus aureus Resistente à Meticilina , Camundongos , Sensibilidade e Especificidade , Infecções Estafilocócicas
18.
J Med Virol ; 93(7): 4219-4241, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33751621

RESUMO

The potential zoonotic coronaviruses (SARS-CoV, MERS-CoV, and SARS-CoV-2) are of global health concerns. Early diagnosis is the milestone in their mitigation, control, and eradication. Many diagnostic techniques are showing great success and have many advantages, such as the rapid turnover of the results, high accuracy, and high specificity and sensitivity. However, some of these techniques have several pitfalls if samples were not collected, processed, and transported in the standard ways and if these techniques were not practiced with extreme caution and precision. This may lead to false-negative/positive results. This may affect the downstream management of the affected cases. These techniques require regular fine-tuning, upgrading, and optimization. The continuous evolution of new strains and viruses belong to the coronaviruses is hampering the success of many classical techniques. There are urgent needs for next generations of coronaviruses diagnostic assays that overcome these pitfalls. This new generation of diagnostic tests should be able to do simultaneous, multiplex, and high-throughput detection of various coronavirus in one reaction. Furthermore, the development of novel assays and techniques that enable the in situ detection of the virus on the environmental samples, especially air, water, and surfaces, should be given considerable attention in the future. These approaches will have a substantial positive impact on the mitigation and eradication of coronaviruses, including the current SARS-CoV-2 pandemic.


Assuntos
COVID-19/diagnóstico , Ensaios de Triagem em Larga Escala/métodos , Síndrome Respiratória Aguda Grave/diagnóstico , Ensaio de Imunoadsorção Enzimática/métodos , Imunofluorescência/métodos , Genoma Viral/genética , Humanos , Coronavírus da Síndrome Respiratória do Oriente Médio/genética , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Vírus da SARS/genética , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , Glicoproteína da Espícula de Coronavírus/genética , Ensaio de Placa Viral/métodos
19.
Sci Rep ; 11(1): 5538, 2021 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-33692390

RESUMO

Understanding antibody responses to SARS-CoV-2 is indispensable for the development of containment measures to overcome the current COVID-19 pandemic. Recent studies showed that serum from convalescent patients can display variable neutralization capacities. Still, it remains unclear whether there are specific signatures that can be used to predict neutralization. Here, we performed a detailed analysis of sera from a cohort of 101 recovered healthcare workers and we addressed their SARS-CoV-2 antibody response by ELISA against SARS-CoV-2 Spike receptor binding domain and nucleoprotein. Both ELISA methods detected sustained levels of serum IgG against both antigens. Yet, the majority of individuals from our cohort generated antibodies with low neutralization capacity and only 6% showed high neutralizing titers against both authentic SARS-CoV-2 virus and the Spike pseudotyped virus. Interestingly, higher neutralizing sera correlate with detection of -IgG, IgM and IgA antibodies against both antigens, while individuals with positive IgG alone showed poor neutralization response. These results suggest that having a broader repertoire of antibodies may contribute to more potent SARS-CoV-2 neutralization. Altogether, our work provides a cross sectional snapshot of the SARS-CoV-2 neutralizing antibody response in recovered healthcare workers and provides preliminary evidence that possessing multiple antibody isotypes can play an important role in predicting SARS-CoV-2 neutralization.


Assuntos
Anticorpos Neutralizantes/imunologia , COVID-19/imunologia , SARS-CoV-2/imunologia , Adulto , Anticorpos Antivirais/imunologia , COVID-19/terapia , Estudos de Coortes , Estudos Transversais , Ensaio de Imunoadsorção Enzimática/métodos , Epitopos/imunologia , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Masculino , Testes de Neutralização/métodos , Pandemias , SARS-CoV-2/patogenicidade , Soro/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia
20.
Trop Med Int Health ; 26(6): 621-631, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33666297

RESUMO

OBJECTIVES: Specific serological tests are mandatory for reliable SARS-CoV-2 diagnostics and seroprevalence studies. Here, we assess the specificities of four commercially available SARS-CoV-2 IgG ELISAs in serum/plasma panels originating from Africa, South America, and Europe. METHODS: 882 serum/plasma samples collected from symptom-free donors before the COVID-19 pandemic in three African countries (Ghana, Madagascar, Nigeria), Colombia, and Germany were analysed with three nucleocapsid-based ELISAs (Euroimmun Anti-SARS-CoV-2-NCP IgG, EDI™ Novel Coronavirus COVID-19 IgG, Mikrogen recomWell SARS-CoV-2 IgG), one spike/S1-based ELISA (Euroimmun Anti-SARS-CoV-2 IgG), and in-house common cold CoV ELISAs. RESULTS: High specificity was confirmed for all SARS-CoV-2 IgG ELISAs for Madagascan (93.4-99.4%), Colombian (97.8-100.0%), and German (95.9-100.0%) samples. In contrast, specificity was much lower for the Ghanaian and Nigerian serum panels (Ghana: NCP-based assays 77.7-89.7%, spike/S1-based assay 94.3%; Nigeria: NCP-based assays 39.3-82.7%, spike/S1-based assay 90.7%). 15 of 600 African sera were concordantly classified as positive in both the NCP-based and the spike/S1-based Euroimmun ELISA, but did not inhibit spike/ACE2 binding in a surrogate virus neutralisation test. IgG antibodies elicited by previous infections with common cold CoVs were found in all sample panels, including those from Madagascar, Colombia, and Germany and thus do not inevitably hamper assay specificity. Nevertheless, high levels of IgG antibodies interacting with OC43 NCP were found in all 15 SARS-CoV-2 NCP/spike/S1 ELISA positive sera. CONCLUSIONS: Depending on the chosen antigen and assay protocol, SARS-CoV-2 IgG ELISA specificity may be significantly reduced in certain populations probably due to interference of immune responses to endemic pathogens like other viruses or parasites.


Assuntos
Anticorpos Antivirais/sangue , COVID-19/diagnóstico , Ensaio de Imunoadsorção Enzimática/métodos , Imunoglobulina G/sangue , Adolescente , Adulto , COVID-19/virologia , Criança , Pré-Escolar , Colômbia , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Feminino , Alemanha , Gana , Humanos , Madagáscar , Masculino , Pessoa de Meia-Idade , Nigéria , SARS-CoV-2/imunologia , SARS-CoV-2/isolamento & purificação , Sensibilidade e Especificidade , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto Jovem
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