Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 152.831
Filtrar
1.
Sci Total Environ ; 753: 141950, 2021 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-32906044

RESUMEN

2,4-dichlorophenoxyacetic acid (2,4-D), a widely used herbicide, is a small organic chemical pollutant in the environment. To develop a nanobody-based immunoassay for monitoring trace levels of 2,4-D, a step-wise strategy for the generation of nanobodies highly specific against this small chemical was employed. Firstly, we synthesized three novel haptens mimicking 2,4-D and assessed their influence on the sensitivity and specificity of the existing antibody-based assay. Polyclonal antibodies (pAb) from rabbits showed good sensitivity and moderate specificity for 2,4-D, pAb from llama based on selected haptens showed similar performance when compared to those from rabbits. Secondly, nanobodies derived from llama were generated for 2,4-D by an effective procedure, including serum monitoring and one-step library construction. One nanobody, NB3-9, exhibited good sensitivity against 2,4-D (IC50 = 29.2 ng/mL) had better specificity than the rabbit pAb#1518, with no cross-reactivities against the 2,4-D analogs tested. Thirdly, one-step fluorescent enzyme immunoassay (FLEIA) for 2,4-D based on a nanobody-alkaline phosphatase (AP) fusion was developed with IC50 of 1.9 ng/mL and a linear range of 0.4-8.6 ng/mL. Environmental water samples were analyzed by FLEIA and LC-MS/MS for comparison, and the results were consistent between both methods. Therefore, the proposed step-wise strategy from hapten design to nanobody-AP fusion production was successfully conducted, and the resulting nanobody based FLEIA was demonstrated as a convenient tool to monitor 2,4-D residuals in the environment.


Asunto(s)
Herbicidas , Agua , Ácido 2,4-Diclorofenoxiacético , Animales , Cromatografía Liquida , Ensayo de Inmunoadsorción Enzimática , Herbicidas/análisis , Conejos , Espectrometría de Masas en Tándem
2.
J Infect Chemother ; 27(1): 120-122, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32988731

RESUMEN

INTRODUCTION: Information on the effectiveness of personal protective equipment (PPE) for preventing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among healthcare workers (HCWs), especially among HCWs with frequent contact with patients with SARS-CoV-2, is limited. METHODS: We conducted a prospective cohort study on 49 HCWs who worked in close contact with patients with SARS-CoV-2 infection. HCWs had blood samples taken every 2 weeks to test for SARS-CoV-2 antibodies using two different types of assay. RESULTS: Forty-nine participants (31 nurses, 15 doctors, 3 other workers) were enrolled. In total, 112 blood samples are obtained from participants. The median work days in 2 weeks was 9 (interquartile range (IQR): 5-10) days. In a single work day, 30 of the 49 participants (61.5%) had contact with patients with suspected or conformed SARS-CoV-2 at least 8 times, and approximately 60% of participants had more than 10 min of contact with a single patient. The median self-reported compliance to PPE was 90% (IQR: 80-100%). Seven participants tested positive for SARS-CoV-2 antibody using enzyme-linked immunosorbent assay (ELISA); however, none were seropositive for SARS-CoV-2 neutralizing antibody, so the positive ELISA results were assumed to be false-positive. CONCLUSIONS: The study provides evidence that appropriate PPE is sufficient to prevent infection amongHCWs. It is necessary to establish a system that provides a stable supply of PPE for HCWs to perform their duties.


Asunto(s)
Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/transmisión , Personal de Salud , Transmisión de Enfermedad Infecciosa de Paciente a Profesional/prevención & control , Pandemias/prevención & control , Equipo de Protección Personal , Neumonía Viral/prevención & control , Neumonía Viral/transmisión , Adulto , Anciano , Anticuerpos Antivirales/sangre , Betacoronavirus/inmunología , Betacoronavirus/aislamiento & purificación , Infecciones por Coronavirus/diagnóstico , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neumonía Viral/diagnóstico , Estudios Prospectivos , Adulto Joven
3.
Food Chem ; 335: 127600, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-32736155

RESUMEN

Toosendanin (TSN), as an important Chinese traditional insecticide, has been registered and commercialized in China. In this report, the residual analytical methods, residue dynamics and final residues of TSN in tobacco, cabbage and soil under field condition were studied by IC-ELISA and HPLC. The sensitivity, precision and repeatability of IC-ELISA method were more suitable in comparison with HPLC for the demand of TSN residue analysis. Using IC-ELISA, the half-lives (t1/2) of TSN were found to be 1.30 days in cabbage, 1.70 days in tabacco and 0.71 days in soil, respectively. At the recommended dose, the final residues of TSN detection by IC-ELISA was 0.009 mg·kg-1 in cabbage and 0.043 mg·kg-1 in tobacco, as well as was not detected in soil. Therefore, TSN is easily degradable, and IC-ELISA could be a convenient and supplemental analytical tool for monitoring TSN residue in crops and environment.


Asunto(s)
Brassica/metabolismo , Medicamentos Herbarios Chinos/metabolismo , Ensayo de Inmunoadsorción Enzimática/métodos , Contaminantes del Suelo/metabolismo , Suelo/química , China , Cromatografía Líquida de Alta Presión/métodos , Semivida , Cinética , Residuos de Plaguicidas/análisis , Tabaco
4.
Zhongguo Zhong Yao Za Zhi ; 45(17): 4158-4162, 2020 Sep.
Artículo en Chino | MEDLINE | ID: mdl-33164401

RESUMEN

The enzyme linked immunosorbent assay of aflatoxin has been adopted in Chinese Pharmacopoeia(2020 edition). Based on high-throughput screening of monoclonal antibodies technology, monoclonal antibodies that can specifically recognize the aflatoxin B_1 and the total amount of aflatoxin B_1, B_2, G_1, and G_2 in Chinese herbal medicines were prepared. By optimizing the concentration of coating antibody, enzyme-labeled antigen, and the reaction system of enzyme-linked immunosorbent assay, the enzyme linked immunosorbent assay(ELISA) were developed for detection of aflatoxins in Chinese herbal medicines, decoction pieces, and preparation of Chinese medicine. In this method, the recovery test of actual samples is 60%-120%, and the relative standard deviation is less than 15%. In addition, in view of the complicated and expensive pretreatment methods for the determination of aflatoxin in Chinese herbal medicine, we developed a highly efficient pretreatment method of liquid-liquid extraction of aflatoxin in Chinese herbal medicine without immunoaffinity column. As an effective method for the detection of aflatoxin, the ELISA can effectively reduce the aflatoxins testing cost of traditional Chinese medicine, and promote the detection ability at earlier stages of production, and strengthen the quality supervision of traditional Chinese medicine.


Asunto(s)
Aflatoxinas , Medicamentos Herbarios Chinos , Aflatoxina B1 , Anticuerpos Monoclonales , Contaminación de Medicamentos , Ensayo de Inmunoadsorción Enzimática
5.
Euro Surveill ; 25(45)2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33183404

RESUMEN

We analysed factors associated with neutralising antibody levels in 330 convalescent plasma donors. Women and younger donors were more likely not to have measurable neutralising antibodies, while higher antibody levels were observed in men, in older donors and in those who had been hospitalised. These data will be of value in the timely recruitment of convalescent plasma donors most likely to have high levels of neutralising antibodies for ongoing studies investigating its effectiveness.


Asunto(s)
Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Betacoronavirus/inmunología , Donantes de Sangre , Infecciones por Coronavirus/sangre , Infecciones por Coronavirus/terapia , Hospitalización , Neumonía Viral/sangre , Neumonía Viral/terapia , Factores de Edad , Anciano , Anticuerpos Neutralizantes/uso terapéutico , Donantes de Sangre/estadística & datos numéricos , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/inmunología , Inglaterra , Ensayo de Inmunoadsorción Enzimática , Humanos , Inmunización Pasiva , Masculino , Pandemias , Neumonía Viral/diagnóstico , Neumonía Viral/inmunología , Factores Sexuales
6.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 32(5): 534-536, 2020 Aug 06.
Artículo en Chino | MEDLINE | ID: mdl-33185070

RESUMEN

OBJECTIVE: To investigate the prevalence of Toxoplasma gondii and Toxocara infections among pregnant women in Hangzhou City, so as to provide baseline data for decreasing birth defects and improving the population quality. METHODS: A total of 235 pregnant women receiving prenatal diagnosis at the First People's Hospital of Yuhang District during the period between February 2018 through December 2019 were recruited as the observation group, and 235 age-matched, non-pregnant healthy women at the same hospital during the same period served as the control group. The subjects'medical records were captured from the hospital management information system. Blood samples were collected from the observation and control groups and detected for the presence of IgG antibodies against T. gondii and Toxocara using an enzyme-linked immunosorbent assay (ELISA). The seroprevalence of the IgG antibodies against T. gondii and Toxocara was compared between the observation and control groups. RESULTS: The subjects in the observation group had a mean age of 26.5 ± 4.3 years (range, 23 to 31 years), and gestational ages of 10 to 27 weeks, and the subjects in the control group had a mean age of 26.1 ± 5.7 years (range, 20 to 30 years). The seroprevalence rates of IgG antibodies against T. gondii (28.51% vs. 4.68%; χ2 = 34.85, P < 0.01) and Toxocara (24.26% vs. 5.11%; χ2 = 25.77, P < 0.01) were both significantly higher in the observation group than in the control group, and the seroprevalence of T. gondii and Toxocara co-infections was also significantly greater in the observation group than in the control group (13.19% vs. 2.13%; χ2 = 17.49, P < 0.01). CONCLUSIONS: The seroprevalence rates of T. gondii and Toxocara infections and their co-infections are all high among pregnant women in Hangzhou City. Screening of T. gondii and Toxocara infections is strongly recommended during pregnancy.


Asunto(s)
Complicaciones Parasitarias del Embarazo/epidemiología , Toxocariasis/epidemiología , Toxoplasmosis , Adulto , Animales , Anticuerpos Antiprotozoarios/sangre , China , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Embarazo , Factores de Riesgo , Estudios Seroepidemiológicos , Toxocara , Toxoplasma , Toxoplasmosis/epidemiología , Adulto Joven
7.
BMC Infect Dis ; 20(1): 835, 2020 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-33176708

RESUMEN

BACKGROUND: The spatial distribution and burden of dengue in sub-Saharan Africa remains highly uncertain, despite high levels of ecological suitability. The goal of this study was to describe the epidemiology of dengue among a cohort of febrile children presenting to outpatient facilities located in areas of western Uganda with differing levels of urbanicity and malaria transmission intensity. METHODS: Eligible children were first screened for malaria using rapid diagnostic tests. Children with a negative malaria result were tested for dengue using a combination NS1/IgM/IgG rapid test (SD Bioline Dengue Duo). Confirmatory testing by RT-PCR was performed in a subset of participants. Antigen-capture ELISA was performed to estimate seroprevalence. RESULTS: Only 6 of 1416 (0.42%) children had a positive dengue rapid test, while none of the RT-PCR results were positive. ELISA testing demonstrated reactive IgG antibodies in 28 (2.2%) participants with the highest prevalence seen at the urban site in Mbarara (19 of 392, 4.9%, p < 0.001). CONCLUSIONS: Overall, these findings suggest that dengue, while present, is an uncommon cause of non-malarial, pediatric febrile illness in western Uganda. Further investigation into the eocological factors that sustain low-level transmission in urban settings are urgently needed to reduce the risk of epidemics.


Asunto(s)
Virus del Dengue/genética , Virus del Dengue/inmunología , Dengue/diagnóstico , Dengue/epidemiología , Fiebre/diagnóstico , Adolescente , Niño , Preescolar , Dengue/virología , Pruebas Diagnósticas de Rutina/efectos adversos , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Inmunoglobulina G/inmunología , Inmunoglobulina M/inmunología , Malaria/diagnóstico , Malaria/epidemiología , Malaria/parasitología , Masculino , Plasmodium/inmunología , Plasmodium/aislamiento & purificación , Prevalencia , Estudios Prospectivos , Reacción en Cadena en Tiempo Real de la Polimerasa , Estudios Seroepidemiológicos , Uganda/epidemiología
8.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 36(10): 934-940, 2020 Oct.
Artículo en Chino | MEDLINE | ID: mdl-33148389

RESUMEN

Objective To prepare and preliminarily identify anti-mouse CD226 monoclonal antibodies (mAbs) using CD226 knockout (CD226 KO) mice as immunized animals. Methods Animals were immunized by recombinant mouse CD226 protein expressed by eukaryotic cells. Anti-mouse CD226 mAbs were prepared by conventional B-cell hybridoma technology. The application of the generated mAbs for flow cytometry and Western blotting was tested. A sandwich ELISA system was established for the detection of soluble CD226 in mice. And the concentrations of plasma soluble CD226 was determined by this sandwich ELISA system in an LPS-induced sepsis mouse model. Results Two hybridoma cell lines secreting mouse anti-mouse CD226 mAbs were successfully prepared. The clones were named mA1.1 and mA1.3, respectively. The antibody subclasses were both IgG1, and the light chains were κ. The obtained mAbs could be applied for flow cytometry to detect exogenous transfected CD226 on the cell surface and natural CD226 on the mouse platelet membrane. In Western blot assay, the mAb could bind to lymphocyte membrane proteins with a relative molecular mass (Mr) of 67 000 that was consistent with the Mr of CD226. In the sandwich ELISA system, the purified mAbs of mA1.3 were coated on ELISA plates as capture antibody, and the mAbs of mA1.1 were labeled with horseradish peroxidase or biotin as detection antibody. The detection sensitivities were 3.0 and 0.25 ng/mL, respectively. The concentration of plasma soluble CD226 of the septic mice was lower than that of the normal mice in the control group. Conclusion The mouse mAbs for identifying mouse CD226 have been prepared successfully and can be applied in various detection techniques.


Asunto(s)
Anticuerpos Monoclonales/biosíntesis , Antígenos de Diferenciación de Linfocitos T/inmunología , Animales , Western Blotting , Ensayo de Inmunoadsorción Enzimática , Hibridomas , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Sepsis
9.
Sheng Wu Gong Cheng Xue Bao ; 36(10): 2206-2215, 2020 Oct 25.
Artículo en Chino | MEDLINE | ID: mdl-33169584

RESUMEN

Dengue virus (DENV) is the most widely transmitted arbovirus in the world. Due to the lack of diagnostic technology to quickly identify the virus serotypes in patients, severe dengue hemorrhagic fever cases caused by repeated infections remain high. To realize the rapid differential diagnosis of different serotypes of DENV infection by immunological methods, in this study, four DENV serotype NS1 proteins were expressed and purified in mammalian cells. Monoclonal antibodies (MAbs) against NS1 protein were obtained by hybridoma technology after immunizing BALB/c mice. Enzyme-linked immunosorbent assay, indirect immunofluorescence assay, dot blotting, and Western blotting were used to confirm the reactivity of MAbs to viral native NS1 and recombinant NS1 protein. These MAbs include not only the universal antibodies that recognize all DENV 1-4 serotype NS1, but also serotype-specific antibodies against DENV-1, DENV-2 and DENV-4. Double antibody sandwich ELISA was established based on these antibodies, which can be used to achieve rapid differential diagnosis of serotypes of DENV infection. Preparation of DENV serotype-specific MAbs and establishment of an ELISA technology for identifying DENV serotypes has laid the foundation for the rapid diagnosis of DENV clinical infection.


Asunto(s)
Anticuerpos Antivirales , Virus del Dengue , Dengue , Animales , Anticuerpos Monoclonales , Anticuerpos Antivirales/clasificación , Anticuerpos Antivirales/genética , Anticuerpos Antivirales/metabolismo , Dengue/diagnóstico , Virus del Dengue/inmunología , Ensayo de Inmunoadsorción Enzimática , Humanos , Ratones , Ratones Endogámicos BALB C , Sensibilidad y Especificidad , Serogrupo , Proteínas no Estructurales Virales/genética , Proteínas no Estructurales Virales/inmunología
10.
Vaccine ; 38(46): 7205-7212, 2020 10 27.
Artículo en Inglés | MEDLINE | ID: mdl-33010978

RESUMEN

The development of an effective vaccine against SARS-CoV-2 is urgently needed. We generated SARS-CoV-2 RBD-Fc fusion protein and evaluated its potency to elicit neutralizing antibody response in mice. RBD-Fc elicited a higher neutralizing antibodies titer than RBD as evaluated by a pseudovirus neutralization assay and a live virus based microneutralization assay. Furthermore, RBD-Fc immunized sera better inhibited cell-cell fusion, as evaluated by a quantitative cell-cell fusion assay. The cell-cell fusion assay results correlated well with the virus neutralization potency and could be used for high-throughput screening of large panels of anti-SARS-CoV-2 antibodies and vaccines without the requirement of live virus infection in BSL3 containment. Moreover, the anti-RBD sera did not enhance the pseudotyped SARS-CoV-2 infection of K562 cells. These results demonstrate that Fc fusion can significantly improve the humoral immune response to recombinant RBD immunogen, and suggest that RBD-Fc could serve as a useful component of effective vaccines against SARS-CoV-2.


Asunto(s)
Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Infecciones por Coronavirus/prevención & control , Fragmentos Fc de Inmunoglobulinas/inmunología , Pandemias/prevención & control , Neumonía Viral/prevención & control , Glicoproteína de la Espiga del Coronavirus/inmunología , Vacunas Virales/inmunología , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Betacoronavirus/inmunología , Fusión Celular , Línea Celular , Infecciones por Coronavirus/inmunología , Ensayo de Inmunoadsorción Enzimática , Femenino , Células HEK293 , Ensayos Analíticos de Alto Rendimiento/métodos , Humanos , Inmunidad Humoral/inmunología , Fragmentos Fc de Inmunoglobulinas/genética , Ratones , Ratones Endogámicos BALB C , Pruebas de Neutralización , Peptidil-Dipeptidasa A/genética , Dominios Proteicos/inmunología , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunología , Glicoproteína de la Espiga del Coronavirus/genética , Vacunas de Subunidad/inmunología
11.
PLoS One ; 15(10): e0241104, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33085715

RESUMEN

BACKGROUND: To accurately interpret COVID-19 seroprevalence surveys, knowledge of serum-IgG responses to SARS-CoV-2 with a better understanding of patients who do not seroconvert, is imperative. This study aimed to describe serum-IgG responses to SARS-CoV-2 in a cohort of patients with both severe and mild COVID-19, including extended studies of patients who remained seronegative more than 90 days post symptom onset. METHODS: SARS-CoV-2-specific IgG antibody levels were quantified using two clinically validated and widely used commercial serological assays (Architect, Abbott Laboratories and iFlash 1800, YHLO), detecting antibodies against the spike and nucleocapsid proteins. RESULTS: Forty-seven patients (mean age 49 years, 38% female) were included. All (15/15) patients with severe symptoms and 29/32 (90.6%) patients with mild symptoms of COVID-19 developed SARS-CoV-2-specific IgG antibodies in serum. Time to seroconversion was significantly shorter (median 11 vs. 22 days, P = 0.04) in patients with severe compared to mild symptoms. Of the three patients without detectable IgG-responses after >90 days, all had detectable virus-neutralizing antibodies and in two, spike-protein receptor binding domain-specific IgG was detected with an in-house assay. Antibody titers were preserved during follow-up and all patients who seroconverted, irrespective of the severity of symptoms, still had detectable IgG levels >75 days post symptom onset. CONCLUSIONS: Patients with severe COVID-19 both seroconvert earlier and develop higher concentrations of SARS-CoV-2-specific IgG than patients with mild symptoms. Of those patients who not develop detectable IgG antibodies, all have detectable virus-neutralizing antibodies, suggesting immunity. Our results showing that not all COVID-19 patients develop detectable IgG using two validated commercial clinical methods, even over time, are vital for the interpretation of COVID-19 seroprevalence surveys.


Asunto(s)
Anticuerpos Antivirales/sangre , Betacoronavirus/inmunología , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/inmunología , Inmunoglobulina G/sangre , Neumonía Viral/epidemiología , Neumonía Viral/inmunología , Índice de Severidad de la Enfermedad , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Neutralizantes/sangre , Betacoronavirus/genética , Infecciones por Coronavirus/virología , Ensayo de Inmunoadsorción Enzimática , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pandemias , Neumonía Viral/virología , Reacción en Cadena en Tiempo Real de la Polimerasa , Seroconversión , Estudios Seroepidemiológicos , Suecia/epidemiología
12.
Parasitol Res ; 119(11): 3699-3703, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33006039

RESUMEN

The objective of the present study was to determine the seroprevalence of Fasciola hepatica infection in horses, donkeys and mules from different climate regions in two states of Mexico. A total of 594 serum samples were analysed for immunoglobulin G (IgG) antibodies using enzyme-linked immunosorbent assay (ELISA), with excretory-secretory (E/S) products as the antigen. The diagnostic sensitivity and specificity of serum IgG ELISA were 100% and 97.2%, respectively. We collected data using a questionnaire. The overall prevalence of the parasite in equids between May 2018 and April 2019 was 13.1% (78 out of 594). The highest prevalence was found in mules (17.9%), followed by that in donkeys (13.9%) and horses (10.4%). In addition, the highest percentage of positive equines was detected in samples from the tropical climate (17.5%). The identification of risk factors was assessed by bivariate logistic regression analysis. Mules had 8.608 times higher risk for F. hepatica infections as compared with horses (odds ratio (OR) 8.608; 95% confidence interval (CI): 2.809-26.377), while the OR for 6-10-year-old equines was 93.375 compared with that of young equines (≤ 5 years old) (OR 93.375; 95% CI: 11.075-787.239). Likewise, tropical climate equines had 83.7% increased odds for fasciolosis (OR 1.83).


Asunto(s)
Equidae/parasitología , Fasciola hepatica/aislamiento & purificación , Fascioliasis/veterinaria , Animales , Ensayo de Inmunoadsorción Enzimática , Fascioliasis/epidemiología , Fascioliasis/parasitología , Femenino , Caballos/parasitología , Inmunoglobulina G/sangre , Masculino , México/epidemiología , Oportunidad Relativa , Prevalencia , Factores de Riesgo , Estudios Seroepidemiológicos
13.
PLoS One ; 15(10): e0240395, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33091042

RESUMEN

BACKGROUND: Coronavirus disease 2019 (COVID-19) is an emerging threat worldwide. This study aims to assess the serologic profiles and time kinetics of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients with COVID-19 using two immunoassays. METHODS: A total of 97 samples serially collected from 17 patients with COVID-19 and 137 negative control samples were analyzed for IgM and IgG against SARS-CoV-2 using the AFIAS COVID-19 Ab (Boditech Med Inc., Chuncheon, Republic of Korea) and the EDI™ Novel Coronavirus COVID-19 ELISA Kit (Epitope Diagnostics, Inc., San Diego, CA). RESULTS: With both assays, IgM and IgG rapidly increased after 7 days post symptom onset (PSO). IgM antibody levels reached a peak at 15-35 d PSO and gradually decreased. IgG levels gradually increased and remained at similar levels after 22-35 d. The diagnostic sensitivities of IgM/IgG for ≤14d PSO were 21.4%/35.7~57.1% and increased to 41.2~52.9%/88.2~94.1% at >14 d PSO with specificities of 98.5%/94.2% for AFIAS COVID-19 Ab and 100.0%/96.4% for EDI™ Novel Coronavirus COVID-19 ELISA Kit. Among 137 negative controls, 12 samples (8.8%) showed positive or indeterminate results. CONCLUSIONS: The antibody kinetics against SARS-CoV-2 are similar to common findings of acute viral infectious diseases. Antibody testing is useful for ruling out SARS-CoV-2 infection after 14 d PSO, detecting past infection, and epidemiologic surveys.


Asunto(s)
Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Betacoronavirus/inmunología , Infecciones por Coronavirus/inmunología , Neumonía Viral/inmunología , Pruebas Serológicas/métodos , Adulto , Anciano , Anciano de 80 o más Años , Infecciones por Coronavirus/virología , Ensayo de Inmunoadsorción Enzimática/métodos , Femenino , Técnica del Anticuerpo Fluorescente/métodos , Estudios de Seguimiento , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Inmunoglobulina M/sangre , Inmunoglobulina M/inmunología , Cinética , Masculino , Persona de Mediana Edad , Pandemias , Neumonía Viral/virología , Sensibilidad y Especificidad , Adulto Joven
14.
BMC Infect Dis ; 20(1): 790, 2020 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-33096994

RESUMEN

BACKGROUND: Jamestown Canyon virus (JCV) is a mosquito-borne orthobunyavirus that causes acute febrile illness, meningitis, and meningoencephalitis, mainly among adults. JCV is widely distributed in North America and the number of JCV cases in the U.S. has increased in recent years. Therefore, the central nervous system disease caused by JCV can be considered a potentially re-emerging viral disease. However, the seroprevalence of JCV is unknown in Japan. The purpose of this study is to evaluate the seroprevalence of JCV in the Japanese population. METHODS: We used an IgG enzyme-linked immunosorbent assay (IgG-ELISA) with JCV-infected cell-lysates and/or a neutralizing (NT) antibody assay. The cut-off value of IgG-ELISA was determined using IgG-ELISA to analyze serum specimens from 37 healthy Japanese donors. IgG-ELISA was validated by assessing its sensitivity and specificity, using 38 human serum samples previously tested for the presence or absence of antibodies against JCV and snowshoe hare virus (SSHV), in an in-house NT antibody assay conducted by the Public Health Agency of Canada. The seroepidemiological study was performed using IgG-ELISA and NT antibody assay to analyze 246 human serum samples from the serum bank of the National Institute of Infectious Diseases (NIID) in Japan. RESULTS: The cut-off value of IgG-ELISA was determined at 0.20, based on the mean (- 0.075) and standard deviation (0.092) values using Japanese donors' sera. The sensitivity and the specificity of IgG-ELISA determined using 25 JCV-positive and 4 JCV-negative serum samples were 96 and 100%, respectively. Analysis of the 246 Japanese serum samples revealed that no specimen showed a higher value than the cut-off value of IgG-ELISA, and no sample tested positive by the NT antibody assay. CONCLUSIONS: Our results showed that JCV is not circulating significantly in Japan. To the best of our knowledge, this is the first report to demonstrate the seroprevalence of JCV in the general population in Japan.


Asunto(s)
Anticuerpos Antivirales/inmunología , Virus de la Encefalitis de California/inmunología , Encefalitis de California/epidemiología , Ensayo de Inmunoadsorción Enzimática/métodos , Pruebas de Neutralización/métodos , Adolescente , Adulto , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/sangre , Niño , Preescolar , Culicidae/virología , Encefalitis de California/virología , Femenino , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Lactante , Recién Nacido , Japón/epidemiología , Masculino , Persona de Mediana Edad , Prevalencia , Sensibilidad y Especificidad , Estudios Seroepidemiológicos , Adulto Joven
15.
PLoS One ; 15(10): e0236905, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33119712

RESUMEN

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although Thailand has been fairly effective at controlling the spread of COVID-19, continued disease surveillance and information on antibody response in recovered patients and their close contacts remain necessary in the absence of approved vaccines and antivirals. Here, we examined 217 recovered COVID-19 patients to assess their viral RNA shedding and residual antibodies against SARS-CoV-2. We also evaluated antibodies in blood samples from 308 close contacts of recovered COVID-19 patients. We found that viral RNA remained detectable in 6.6% of recovered COVID-19 cases and up to 105 days. IgM, IgG, and IgA antibodies against SARS-CoV-2 were detected in 13.8%, 88.5%, and 83.4% of the recovered cases 4-12 weeks after disease onset, respectively. Higher levels of antibodies detected were associated with severe illness patients experienced while hospitalized. Fifteen of the 308 contacts (4.9%) of COVID-19 cases tested positive for IgG antibodies, suggesting probable exposure. Viral clearance and the pattern of antibody responses in infected individuals are both crucial for effectively combating SARS-CoV-2. Our study provides additional information on the natural history of this newly emerging disease related to both natural host defenses and antibody duration.


Asunto(s)
Anticuerpos Antivirales/aislamiento & purificación , Infecciones por Coronavirus/inmunología , Neumonía Viral/inmunología , ARN Viral/aislamiento & purificación , Sobrevivientes , Esparcimiento de Virus , Adulto , Betacoronavirus , Ensayo de Inmunoadsorción Enzimática , Composición Familiar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pandemias , Tailandia
16.
BMJ Open ; 10(10): e040036, 2020 10 06.
Artículo en Inglés | MEDLINE | ID: mdl-33028562

RESUMEN

INTRODUCTION: As of 30 April 2020, the novel betacoronavirus SARS-CoV-2 had infected more than 3 172 000 individuals, killing over 224 000 people and spreading to more than 200 countries. Italy was the most affected country in Europe and the third most affected in the world in terms of the number of cases. Therefore, the aims of this study are: (1) to estimate the prevalence of asymptomatic SARS-CoV-2-positive individuals among the general population of Verona; (2) to assess the accuracy (sensitivity, specificity and predictive values) of an ELISA serological test for the screening of SARS-CoV-2. METHODS AND ANALYSIS: The study will be carried out on a random sample of subjects aged at least 10 years from the general population of Verona. Participants will undergo the measurement of vital parameters (oxygen saturation measured by oximeter, respiratory rate and body temperature detected by laser thermometer), the administration of a COVID-19-related symptoms questionnaire, the collection of a blood sample and a nasopharyngeal swab. Our evaluation will include the statistical technique of Latent Class Analysis, which will be the basis for the estimation of prevalence. ETHICS AND DISSEMINATION: The study protocol has been approved by the Ethics Committee of Verona and Rovigo provinces on 15 April 2020 (internal protocol number 2641CESC). The study results will be submitted for publication in international, peer-reviewed journals and the complete dataset will be deposited in a public repository. Most relevant data will be made available to policy-makers as well as disseminated to stakeholders and to the community.


Asunto(s)
Infecciones Asintomáticas/epidemiología , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/epidemiología , Tamizaje Masivo/métodos , Pandemias , Neumonía Viral/diagnóstico , Neumonía Viral/epidemiología , Pruebas Serológicas/métodos , Adulto , Anticuerpos Antivirales/sangre , Betacoronavirus , Niño , Protocolos Clínicos , Infecciones por Coronavirus/sangre , Infecciones por Coronavirus/virología , Estudios Transversales , Ensayo de Inmunoadsorción Enzimática/métodos , Humanos , Inmunoglobulinas/sangre , Italia , Neumonía Viral/sangre , Neumonía Viral/virología , Prevalencia , Proyectos de Investigación , Sensibilidad y Especificidad , Síndrome Respiratorio Agudo Grave
18.
J Med Life ; 13(3): 404-409, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33072216

RESUMEN

In acute peritonitis, any surgical intervention leads to impaired immune protection with the development of postoperative purulent-septic complications, which increases several times the likelihood of death, especially in people with secondary immunodeficiency as a consequence diabetes mellitus. We aimed to study the dynamics of pro- and anti-inflammatory cytokine content in rat serum under experimental acute generalized peritonitis on the background of diabetes mellitus. Fifty-six white rats were used for the study. The determination of the serum cytokine profile was performed by enzyme-linked immunosorbent assay. When comparing the levels of interleukins between the study groups, a statistically significant increase in the level of proinflammatory cytokines was found in the group of diabetic animals during all experimental periods. In particular, the concentration of interleukin - 1ß increased significantly by 94% on day 1 of observation, by 115% on day 3, and by 121% on day 7 compared to the control group. Similarly, a significant increase in TNF-α levels was observed in animals with diabetes. In this group, the most significant increase in the level of TNF-α was recorded on the seventh day of the experiment, and it increased by 3.4 times. Animals with acute peritonitis on the background of diabetes had a significantly increased concentration of anti-inflammatory cytokines in the serum of all study groups, which confirms their involvement in the pathogenesis of the disease under study.


Asunto(s)
Citocinas/sangre , Diabetes Mellitus/sangre , Peritonitis/sangre , Peritonitis/complicaciones , Animales , Ensayo de Inmunoadsorción Enzimática , Mediadores de Inflamación/sangre , Masculino , Ratas , Factor de Necrosis Tumoral alfa/sangre
19.
PLoS One ; 15(10): e0240076, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33022019

RESUMEN

Public health emergency of SARS-CoV-2 has facilitated diagnostic testing as a related medical countermeasure against COVID-19 outbreak. Numerous serologic antibody tests have become available through an expedited federal emergency use only process. This paper highlights the analytical characteristic of an ELISA based assay by AnshLabs and three random access immunoassay (RAIA) by DiaSorin, Roche, and Abbott that have been approved for emergency use authorization (EUA), at a tertiary academic center in a low disease-prevalence area. The AnshLabs gave higher estimates of sero-prevalence, over the three RAIA methods. For positive results, AnshLabs had 93.3% and 100% agreement with DiaSorin or Abbott and Roche respectively. For negative results, AnshLabs had 74.3% and 78.3% agreement with DiaSorin and Roche or Abbott respectively. All discrepant samples that were positive by AnshLabs and negative by RAIA tested positive by all-in-one step SARS-CoV-2 Total (COV2T) assay performed on the automated Siemens Advia Centaur XPT analyzer. None of these methods, however, are useful in early diagnosis of SARS-CoV-2.


Asunto(s)
Anticuerpos Antivirales/inmunología , Betacoronavirus/inmunología , Técnicas de Laboratorio Clínico/métodos , Infecciones por Coronavirus/diagnóstico , Ensayo de Inmunoadsorción Enzimática/métodos , Neumonía Viral/diagnóstico , Pruebas Serológicas/métodos , Infecciones por Coronavirus/virología , Pruebas Diagnósticas de Rutina , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Proteínas de la Nucleocápside/inmunología , Pandemias , Neumonía Viral/virología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Sensibilidad y Especificidad , Glicoproteína de la Espiga del Coronavirus/inmunología
20.
Sci Rep ; 10(1): 16561, 2020 10 06.
Artículo en Inglés | MEDLINE | ID: mdl-33024213

RESUMEN

As the Coronavirus Disease 2019 (COVID-19), which is caused by the novel SARS-CoV-2, continues to spread rapidly around the world, there is a need for well validated serological assays that allow the detection of viral specific antibody responses in COVID-19 patients or recovered individuals. In this study, we established and used multiple indirect Enzyme Linked Immunosorbent Assay (ELISA)-based serological assays to study the antibody response in COVID-19 patients. In order to validate the assays we determined the cut off values, sensitivity and specificity of the assays using sera collected from pre-pandemic healthy controls, COVID-19 patients at different time points after disease-onset, and seropositive sera to other human coronaviruses (CoVs). The developed SARS-CoV-2 S1 subunit of the spike glycoprotein and nucleocapsid (N)-based ELISAs not only showed high specificity and sensitivity but also did not show any cross-reactivity with other CoVs. We also show that all RT-PCR confirmed COVID-19 patients tested in our study developed both virus specific IgM and IgG antibodies as early as week one after disease onset. Our data also suggest that the inclusion of both S1 and N in serological testing would capture as many potential SARS-CoV-2 positive cases as possible than using any of them alone. This is specifically important for tracing contacts and cases and conducting large-scale epidemiological studies to understand the true extent of virus spread in populations.


Asunto(s)
Anticuerpos Antivirales/sangre , Betacoronavirus/inmunología , Infecciones por Coronavirus/diagnóstico , Proteínas de la Nucleocápside/inmunología , Neumonía Viral/diagnóstico , Seroconversión , Pruebas Serológicas/métodos , Glicoproteína de la Espiga del Coronavirus/inmunología , Adulto , Anciano , Betacoronavirus/genética , Estudios de Cohortes , Infecciones por Coronavirus/virología , Reacciones Cruzadas , Ensayo de Inmunoadsorción Enzimática/métodos , Femenino , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Masculino , Persona de Mediana Edad , Coronavirus del Síndrome Respiratorio de Oriente Medio/genética , Coronavirus del Síndrome Respiratorio de Oriente Medio/inmunología , Pandemias , Neumonía Viral/virología , Reacción en Cadena en Tiempo Real de la Polimerasa , Sensibilidad y Especificidad , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA