Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 16.583
Filtrar
1.
J Coll Physicians Surg Pak ; 30(1): S26-S28, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33650420

RESUMEN

We present a case of coronavirus disease 2019 (COVID-19) re-infection where the time interval between two COVID-positive episodes is the longest in the literature. A 40-year male patient was admitted to the Emergency Department with  complaints of sore throat, cough and diarrhea; and was re-diagnosed as COVID-19 positive after a virus-free period. He did not have a chronic disease in his anamnesis and used no medication. After COVID-19 infection and a long recovery period, he became COVID-19 positive again. In this case, the time to second COVID-19 infection was 94 days from the first positive PCR test and 86 days from the complete resolution of symptoms. This is one of the longest COVID-19-free period between two episodes of infection in the literature. Key Words: COVID-19, Recurrence, Re-infection, Recovery.


Asunto(s)
/epidemiología , ARN Viral/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , /genética , Adulto , /virología , Humanos , Masculino , Pandemias , Recurrencia
2.
Sci Rep ; 11(1): 5372, 2021 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-33686189

RESUMEN

Wastewater-based epidemiology (WBE) is a great approach that enables us to comprehensively monitor the community to determine the scale and dynamics of infections in a city, particularly in metropolitan cities with a high population density. Therefore, we monitored the time course of the SARS-CoV-2 RNA concentration in raw sewage in the Frankfurt metropolitan area, the European financial center. To determine the SARS-CoV-2 RNA concentration in sewage, we continuously collected 24 h composite samples twice a week from two wastewater treatment plant (WWTP) influents (Niederrad and Sindlingen) serving the Frankfurt metropolitan area and performed RT-qPCR analysis targeting three genes (N gene, S gene, and ORF1ab gene). In August, a resurgence in the SARS-CoV-2 RNA load was observed, reaching 3 × 1013 copies/day, which represented similar levels compared to April with approx. 2 × 1014 copies/day. This corresponds to a continuous increase again in COVID-19 cases in Frankfurt since August, with an average of 28.6 incidences, compared to 28.7 incidences in April. Different temporal dynamics were observed between different sampling points, indicating local dynamics in COVID-19 cases within the Frankfurt metropolitan area. The SARS-CoV-2 RNA load to the WWTP Niederrad ranged from approx. 4 × 1011 to 1 × 1015 copies/day, the load to the WWTP Sindlingen from approx. 1 × 1011 to 2 × 1014 copies/day, which resulted in a preceding increase in these loading in July ahead of the weekly averaged incidences. The study shows that WBE has the potential as an early warning system for SARS-CoV-2 infections and a monitoring system to identify global hotspots of COVID-19.


Asunto(s)
Monitoreo del Ambiente , ARN Viral/análisis , Aguas Residuales/virología , /epidemiología , Ciudades , Monitoreo Epidemiológico , Genes Virales , Alemania , Aguas del Alcantarillado/virología , Factores de Tiempo , Carga Viral , Purificación del Agua
3.
Anal Chim Acta ; 1154: 338330, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33736792

RESUMEN

The recent outbreak of coronavirus disease 2019 (COVID-19) is highly infectious, which threatens human health and has received increasing attention. So far, there is no specific drug or vaccine for COVID-19. Therefore, it is urgent to establish a rapid and sensitive early diagnosis platform, which is of great significance for physical separation of infected persons after rapid diagnosis. Here, we propose a colorimetric/SERS/fluorescence triple-mode biosensor based on AuNPs for the fast selective detection of viral RNA in 40 min. AuNPs with average size of 17 nm were synthesized, and colorimetric, surface enhanced Raman scattering (SERS), and fluorescence signals of sensors are simultaneously detected based on their basic aggregation property and affinity energy to different bio-molecules. The sensor achieves a limit detection of femtomole level in all triple modes, which is 160 fM in absorbance mode, 259 fM in fluorescence mode, and 395 fM in SERS mode. The triple-mode signals of the sensor are verified with each other to make the experimental results more accurate, and the capacity to recognize single-base mismatch in each working mode minimizes the false negative/positive reading of SARS-CoV-2. The proposed sensing platform provides a new way for the fast, sensitive, and selective detection of COVID-19 and other diseases.


Asunto(s)
Técnicas Biosensibles/métodos , Nanopartículas del Metal/química , ARN Viral/análisis , /genética , /virología , Oro/química , Humanos , Límite de Detección , Tamaño de la Partícula , ARN Viral/química , Espectrometría Raman , Glicoproteína de la Espiga del Coronavirus/genética
4.
Anal Chim Acta ; 1154: 338310, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33736798

RESUMEN

Novel coronavirus disease (COVID-19) caused by SARS-CoV-2 is an ongoing global pandemic associated with high rates of morbidity and mortality. RT-qPCR has become the diagnostic standard for the testing of SARS-CoV-2 in most countries. COVID-19 diagnosis generally relies upon RT-qPCR-mediated identification of SARS-CoV-2 viral RNA, which is costly, labor-extensive, and requires specialized training and equipment. Herein, we established a novel one-tube rapid diagnostic approach based upon formamide and colorimetric RT-LAMP (One-Pot RT-LAMP) that can be used to diagnose COVID-19 without the extraction of specific viral RNA. The technique could visually detect SARS-CoV-2 within 45 min with a limit of detection of 5 copies per reaction in extracted RNA, and about 7.66 virus copies per µL in viral transport medium. The One-Pot RT-LAMP test showed a high specificity without cross-reactivity with 12 viruses including SARS-CoV, MERS-CoV, and human infectious influenza virus (H1N1/H3N2 of influenza A and B virus, ect. We validated this One-Pot RT-LAMP approach by its successful use for the analysis of 45 clinical nasopharyngeal swab samples, yielding results identical to those of traditional RT-qPCR analyses, while achieving good selectivity and sensitivity relative to a commercial RT-qPCR approach. As such, this One-Pot RT-LAMP technology may be a valid means of conducting high-sensitivity, low-cost and rapid SARS-CoV-2 identification without the extraction of viral RNA.


Asunto(s)
/métodos , /diagnóstico , /virología , Cartilla de ADN/química , Cartilla de ADN/metabolismo , Humanos , Límite de Detección , Técnicas de Diagnóstico Molecular , Nasofaringe/virología , Técnicas de Amplificación de Ácido Nucleico , ARN Viral/análisis , ARN Viral/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , /aislamiento & purificación , Factores de Tiempo
5.
Viruses ; 13(2)2021 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-33672005

RESUMEN

To predict the clinical outcome of coronavirus disease-2019 (COVID-19), we examined relationships among epidemiological data, viral load, and disease severity. We examined viral loads of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) in fatal (15 cases), symptomatic/survived (133 cases), and asymptomatic cases (138 cases) using reverse transcription quantitative real-time PCR (RT-qPCR). We examined 5768 nasopharyngeal swabs (NPS) and attempted to detect the SARS-CoV-2 genome using RT-qPCR. Among them, the viral genome was detected using the method for the 370 NPS samples with a positive rate of 6.4%. A comparison of each age showed that the fatal case was higher than the survived case and asymptomatic patients. Survived cases were older than asymptomatic patients. Notably, the viral load in the fatal cases was significantly higher than in symptomatic or asymptomatic cases (p < 0.05). These results suggested that a high viral load of the SARS-CoV-2 in elderly patients at an early stage of the disease results in a poor outcome. We should, therefore, intervene early to prevent a severe stage of the disease in such cases.


Asunto(s)
/diagnóstico , Mucosa Nasal/virología , Carga Viral , Adulto , Anciano , Femenino , Humanos , Japón , Masculino , Persona de Mediana Edad , ARN Viral/análisis , Índice de Severidad de la Enfermedad
6.
Open Heart ; 8(1)2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33723014

RESUMEN

OBJECTIVES: The clinical impact of SARS-CoV-2 has varied across countries with varying cardiovascular manifestations. We review the cardiac presentations, in-hospital outcomes and development of cardiovascular complications in the initial cohort of SARS-CoV-2 positive patients at Imperial College Healthcare National Health Service Trust, UK. METHODS: We retrospectively analysed 498 COVID-19 positive adult admissions to our institute from 7 March to 7 April 2020. Patient data were collected for baseline demographics, comorbidities and in-hospital outcomes, especially relating to cardiovascular intervention. RESULTS: Mean age was 67.4±16.1 years and 62.2% (n=310) were male. 64.1% (n=319) of our cohort had underlying cardiovascular disease (CVD) with 53.4% (n=266) having hypertension. 43.2%(n=215) developed acute myocardial injury. Mortality was significantly increased in those patients with myocardial injury (47.4% vs 18.4%, p<0.001). Only four COVID-19 patients had invasive coronary angiography, two underwent percutaneous coronary intervention and one required a permanent pacemaker implantation. 7.0% (n=35) of patients had an inpatient echocardiogram. Acute myocardial injury (OR 2.39, 95% CI 1.31 to 4.40, p=0.005) and history of hypertension (OR 1.88, 95% CI 1.01 to 3.55, p=0.049) approximately doubled the odds of in-hospital mortality in patients admitted with COVID-19 after other variables had been controlled for. CONCLUSION: Hypertension, pre-existing CVD and acute myocardial injury were associated with increased in-hospital mortality in our cohort of COVID-19 patients. However, only a low number of patients required invasive cardiac intervention.


Asunto(s)
/epidemiología , Enfermedades Cardiovasculares/epidemiología , Pandemias , Anciano , Comorbilidad , Femenino , Mortalidad Hospitalaria/tendencias , Humanos , Incidencia , Londres , Masculino , ARN Viral/análisis , Estudios Retrospectivos , Tasa de Supervivencia/tendencias
7.
Epidemiol Infect ; 149: e67, 2021 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-33678202

RESUMEN

The possibility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission by fomites or environmental surfaces has been suggested. It is unclear if SARS-CoV-2 can be detected in outdoor public areas. The objective of the current study was to assess the presence of SARS-CoV-2 in environmental samples collected at public playgrounds and water fountains, in a country with high disease prevalence. Environmental samples were collected from six cities in central Israel. Samples were collected from drinking fountains and high-touch recreational equipment at playgrounds. Sterile pre-moistened swabs were used to collect the samples, put in viral transfer media and transferred to the laboratory. Viral detection was achieved by real-time reverse transcriptase-polymerase chain reaction, targeting four genes. Forty-three samples were collected from playground equipment and 25 samples from water fountains. Two of the 43 (4.6%) samples from playground equipment and one (4%) sample from a drinking fountain tested positive. It is unclear whether the recovery of viral RNA on outdoor surfaces also indicates the possibility of acquiring the virus. Adherence to environmental and personal hygiene in urban settings seems prudent.


Asunto(s)
/transmisión , Contaminación de Equipos/estadística & datos numéricos , Parques Recreativos , Juego e Implementos de Juego , ARN Viral/análisis , /genética , Agua Potable , Humanos , Israel , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
8.
Talanta ; 227: 122154, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33714462

RESUMEN

Infectious diseases caused by viruses such as SARS-CoV-2 and HPV have greatly endangered human health. The nucleic acid detection is essential for the early diagnosis of diseases. Here, we propose a method called PLCR (PfAgo coupled with modified Ligase Chain Reaction for nucleic acid detection) which utilizes PfAgo to only use DNA guides longer than 14-mer to specifically cleave DNA and LCR to precisely distinguish single-base mismatch. PLCR can detect DNA or RNA without PCR at attomolar sensitivities, distinguish single base mutation between the genome of wild type SARS-CoV-2 and its mutant spike D614G, effectively distinguish the novel coronavirus from other coronaviruses and finally achieve multiplexed detection in 70 min. Additionally, LCR products can be directly used as DNA guides without additional input guides to simplify primer design. With desirable sensitivity, specificity and simplicity, the method can be extended for detecting other pathogenic microorganisms.


Asunto(s)
Proteínas Argonauta/química , ADN Viral/análisis , Reacción en Cadena de la Ligasa/métodos , Pyrococcus furiosus/enzimología , ARN Viral/análisis , Alphapapillomavirus/química , Alphapapillomavirus/aislamiento & purificación , ADN Viral/química , Humanos , Límite de Detección , Mutación , Infecciones por Papillomavirus/diagnóstico , ARN Viral/química , /aislamiento & purificación , Sensibilidad y Especificidad , Glicoproteína de la Espiga del Coronavirus/genética
9.
Virol J ; 18(1): 53, 2021 03 10.
Artículo en Inglés | MEDLINE | ID: mdl-33691737

RESUMEN

INTRODUCTION: The sudden arrival of the COVID-19 pandemic placed significant stresses on supply chains including viral transport medium (VTM). The VTM that was urgently required needed to support viral replication, as well as other routine diagnostic approaches. We describe the preparation and validation testing of VTM for rapidly expanding diagnostic testing, where the capacity of the VTM to preserve viral integrity, for culture, isolation and full sequence analysis, was maintained. METHODS: VTM was prepared using different methods of sterilization then 'spiked' with virus. The VTM was investigated using viral culture in Vero cells, and for nucleic acid detection by quantitative PCR. RESULTS: The best results were obtained by filter and autoclave-based sterilization. The VTM proved robust for culture-based analyses provided the inoculated VTM was stored at 4 °C, and tested within 48 h. The filtered VTM also supported PCR-based diagnosis for at least 5 days when the mock inoculated VTM was held at room temperature. DISCUSSION: The manual handling of VTM production, including filling and sterilization, was optimized. SARS-CoV-2 was spiked into VTM to assess different sterilization methods and measure the effects of storage time and temperature upon VTM performance. While most diagnostic protocols will not require replication competent virus, the use of high quality VTM will allow for the next phase of laboratory analysis in the COVID-19 pandemic, including drug and antibody susceptibility analysis of re-isolated SARS-CoV-2, and for the testing of vaccine escape mutants.


Asunto(s)
/diagnóstico , Manejo de Especímenes/métodos , Animales , Antibacterianos/farmacología , Línea Celular , Chlorocebus aethiops , Medios de Cultivo/química , Humanos , ARN Viral/análisis , Células Vero
10.
Int J Mol Sci ; 22(5)2021 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-33671091

RESUMEN

Although molecular testing, and RT-qPCR in particular, has been an indispensable component in the scientific armoury targeting SARS-CoV-2, there are numerous falsehoods, misconceptions, assumptions and exaggerated expectations with regards to capability, performance and usefulness of the technology. It is essential that the true strengths and limitations, although publicised for at least twenty years, are restated in the context of the current COVID-19 epidemic. The main objective of this commentary is to address and help stop the unfounded and debilitating speculation surrounding its use.


Asunto(s)
/métodos , /virología , Técnicas de Diagnóstico Molecular/métodos , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , /aislamiento & purificación , Técnicas de Laboratorio Clínico/métodos , Humanos , ARN Viral/análisis , ARN Viral/genética , Sensibilidad y Especificidad
11.
Indian J Ophthalmol ; 69(3): 773-774, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33595525

RESUMEN

With increasing experience, it has been suggested that the SARS-CoV-2 virus has a neurotropic effect. Here, we present a case of a tonic pupil who developed after COVID-19 infection. A 36-year-old woman presented with progressive photophobia and blurred vision. On neurological examination, loss of deep tendon reflexes accompanying a tonic pupil was detected and brain MR imaging was normal. With this case, we aimed to describe a rare pattern of neurological involvement caused by the possible SARS-CoV-2 virus.


Asunto(s)
Síndrome de Adie/diagnóstico , /complicaciones , Síndrome de Adie/etiología , Adulto , Diagnóstico Diferencial , Femenino , Humanos , Imagen por Resonancia Magnética , ARN Viral/análisis , /genética
12.
ACS Chem Biol ; 16(3): 491-500, 2021 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-33586431

RESUMEN

The outbreak of novel coronavirus SARS-CoV-2 has caused a worldwide threat to public health. COVID-19 patients with SARS-CoV-2 infection can develop clinical symptoms that are often confused with the infections of other respiratory pathogens. Sensitive and specific detection of SARS-CoV-2 with the ability to discriminate from other viruses is urgently needed for COVID-19 diagnosis. Herein, we streamlined a highly efficient CRISPR-Cas12a-based nucleic acid detection platform, termed Cas12a-linked beam unlocking reaction (CALIBURN). We show that CALIBURN could detect SARS-CoV-2 and other coronaviruses and influenza viruses with little cross-reactivity. Importantly, CALIBURN allowed accurate diagnosis of clinical samples with extremely low viral loads, which is a major obstacle for the clinical applications of existing CRISPR diagnostic platforms. When tested on the specimens from SARS-CoV-2-positive and negative donors, CALIBURN exhibited 73.0% positive and 19.0% presumptive positive rates and 100% specificity. Moreover, unlike existing CRISPR detection methods that were mainly restricted to respiratory specimens, CALIBURN displayed consistent performance across both respiratory and nonrespiratory specimens, suggesting its broad specimen compatibility. Finally, using a mouse model of SARS-CoV-2 infection, we demonstrated that CALIBURN allowed detection of coexisting pathogens without cross-reactivity from a single tissue specimen. Our results suggest that CALIBURN can serve as a versatile platform for the diagnosis of COVID-19 and other respiratory infectious diseases.


Asunto(s)
Proteínas Bacterianas/genética , /diagnóstico , Proteínas Asociadas a CRISPR/genética , Sistemas CRISPR-Cas , Endodesoxirribonucleasas/genética , ARN Viral/análisis , /química , Adenoviridae/química , Animales , Colorantes Fluorescentes/química , Humanos , Límite de Detección , Ratones Endogámicos BALB C , Técnicas de Amplificación de Ácido Nucleico , Sondas ARN/genética , ARN Viral/genética , Manejo de Especímenes , Espectrometría de Fluorescencia
13.
Nature ; 592(7852): 122-127, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33636719

RESUMEN

During the evolution of SARS-CoV-2 in humans, a D614G substitution in the spike glycoprotein (S) has emerged; virus containing this substitution has become the predominant circulating variant in the COVID-19 pandemic1. However, whether the increasing prevalence of this variant reflects a fitness advantage that improves replication and/or transmission in humans or is merely due to founder effects remains unknown. Here we use isogenic SARS-CoV-2 variants to demonstrate that the variant that contains S(D614G) has enhanced binding to the human cell-surface receptor angiotensin-converting enzyme 2 (ACE2), increased replication in primary human bronchial and nasal airway epithelial cultures as well as in a human ACE2 knock-in mouse model, and markedly increased replication and transmissibility in hamster and ferret models of SARS-CoV-2 infection. Our data show that the D614G substitution in S results in subtle increases in binding and replication in vitro, and provides a real competitive advantage in vivo-particularly during the transmission bottleneck. Our data therefore provide an explanation for the global predominance of the variant that contains S(D614G) among the SARS-CoV-2 viruses that are currently circulating.


Asunto(s)
/transmisión , Mutación , /fisiología , Glicoproteína de la Espiga del Coronavirus/genética , Replicación Viral/genética , /genética , Animales , Bronquios/citología , Bronquios/virología , Línea Celular , Células Cultivadas , Cricetinae , Modelos Animales de Enfermedad , Células Epiteliales/virología , Femenino , Hurones/virología , Efecto Fundador , Técnicas de Sustitución del Gen , Aptitud Genética , Humanos , Masculino , Mesocricetus , Ratones , Mucosa Nasal/citología , Mucosa Nasal/virología , Unión Proteica , ARN Viral/análisis , /metabolismo , /patogenicidad
14.
Arch Virol ; 166(4): 1071-1081, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33533976

RESUMEN

Elimination of hepatitis C virus (HCV) may fail, leading to a non-response outcome because of inappropriate testing for viral RNA in peripheral blood mononuclear cells (PBMCs). Sequelae of HCV genotype 4 therapy with sofosbuvir and daclatasvir ± ribavirin were assessed in our study at the 12th week after end of treatment (EOT) by screening for viral genomic RNA in serum and PBMCs with correlation to hepatic parenchymal changes. We recruited 102 out of 2165 patients who had received sofosbuvir/daclatasvir, either alone (n = 1573) or together with ribavirin (n = 592). Subjects were classified into three groups based on testing by single-step reverse transcription PCR: group I, HCV negative in both serum and PBMCs (n = 25); group II, HCV positive in PBMCs only (n = 52); and group III, HCV positive in both serum and PBMCs (n = 25). Groups I and II (n = 77) were selected out of 2102 (every 27th subject), while group III (n = 25) were selected from every second or third serologic relapse (n = 63). The pre-sampling population (n = 2165) showed sustained virologic response (SVR) in 33.21%; serologic relapse in 2.91%; HCV RNA only in PBMCs (66.79%) compared to serologic relapses and potential cure (P < 0.0001); higher serologic (38 out of 63, P = 0.03210) and cellular (36 out of 52, P = 0.0002) relapses in dual therapy than in triple therapy. The post-sampling population (n = 102) showed more HCV relapses in dual (50 out of 60) than in triple (27 out of 42) therapy (P = 0.0351); increased HCV antisense RNA strand in relapses compared to positive-sense strands alone (P < 0.001); and significant SVR events in undetectable (15 out of 31) compared to early (10 out of 55, P = 0.0058) and cirrhotic liver tissue changes (0 out of 16, P = 0.0006). In summary, HCV treatment with sofosbuvir/daclatasvir is followed by higher rates of serologic and intracellular viral RNA relapse than treatment with sofosbuvir/daclatasvir plus ribavirin. Cellular and serum viral RNA relapses are accompanied by HCV-induced hepatic pathology. An increased SVR with no detectable liver tissue changes was observed after triple therapy due to elimination of HCV RNA from PBMCs.


Asunto(s)
Antivirales/uso terapéutico , Hepacivirus/efectos de los fármacos , Hepatitis C Crónica/tratamiento farmacológico , ARN Viral/efectos de los fármacos , Ribavirina/uso terapéutico , Adulto , Carbamatos/uso terapéutico , Quimioterapia Combinada , Femenino , Hepacivirus/genética , Hepatitis C Crónica/patología , Hepatitis C Crónica/virología , Humanos , Imidazoles/uso terapéutico , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/virología , Hígado/efectos de los fármacos , Hígado/patología , Masculino , Persona de Mediana Edad , Tejido Parenquimatoso/efectos de los fármacos , Tejido Parenquimatoso/patología , Pirrolidinas/uso terapéutico , ARN Viral/análisis , Prevención Secundaria , Sofosbuvir/uso terapéutico , Resultado del Tratamiento , Valina/análogos & derivados , Valina/uso terapéutico
15.
Arch Virol ; 166(4): 1193-1196, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33580378

RESUMEN

The correlation of viral growth capability (n = 156) with the viral load in nasopharyngeal swabs (n = 76) was assessed. Epidemic influenza A/H1N1, A/H3N2, and B viruses showed a wide range of growth capability (104-1011 copies/mL) in Madin-Darby canine kidney cells. The growth was correlated with the nasopharyngeal viral load (r = 0.53). Six selected strains showed growth-dependent cell death (r = 0.96) in a growth kinetics assay. Epidemic influenza viruses exhibit a wide range of growth capability. Growth capability should be considered one of the key factors in disease prognosis.


Asunto(s)
Epidemias , Gripe Humana/epidemiología , Gripe Humana/virología , Orthomyxoviridae/crecimiento & desarrollo , Células A549 , Animales , Supervivencia Celular , Perros , Humanos , Japón/epidemiología , Células de Riñón Canino Madin Darby , Nasofaringe/virología , Orthomyxoviridae/clasificación , Orthomyxoviridae/genética , Orthomyxoviridae/aislamiento & purificación , Pronóstico , ARN Viral/análisis , Carga Viral
16.
Biosens Bioelectron ; 178: 113041, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33545551

RESUMEN

The outbreak of COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been challenging human health worldwide. Loop-mediated isothermal amplification (LAMP) has been promptly applied to the detection of SARS-CoV-2 owing to its high amplification efficacy and less requirement of the thermal cycler. However, the vast majority of these LAMP-based assays depend on the non-specific detection of LAMP products, which can not discern the undesirable amplificons, likely to yield unreliable results. Herein, a sequence-specific LAMP assay was reported to detect SARS-CoV-2 using proofreading enzyme-mediated probe cleavage (named Proofman), which could realize real-time and visual detection without uncapping. This assay, introducing a proofreading enzyme and the fluorogenic probe to reverse-transcription LAMP (RT-Proofman-LAMP), can specifically detect the SARS-CoV-2 RNA with a detection limit of 100 copies. In addition to the real-time analysis, the assay is capable of endpoint visualization under a transilluminator within 50 min, providing a convenient reporting manner under the setting of point-of-care testing (POCT). In combination with different fluorophores, the one-pot multiplex assay was successfully achieved to detect multiple targets of SARS-CoV-2 and inner control simultaneously. In summary, the development of RT-Proofman-LAMP offers a versatile and highly-specific method for fast field screening and laboratory testing of SARS-CoV-2, making it a promising platform in COVID-19 diagnosis.


Asunto(s)
/métodos , /virología , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , /aislamiento & purificación , Técnicas Biosensibles/métodos , Técnicas Biosensibles/estadística & datos numéricos , Humanos , Límite de Detección , Técnicas de Diagnóstico Molecular/estadística & datos numéricos , Reacción en Cadena de la Polimerasa Multiplex/métodos , Reacción en Cadena de la Polimerasa Multiplex/estadística & datos numéricos , Técnicas de Amplificación de Ácido Nucleico/estadística & datos numéricos , Pandemias , Sistemas de Atención de Punto/estadística & datos numéricos , ARN Viral/análisis , ARN Viral/genética , Sensibilidad y Especificidad
17.
Proc Natl Acad Sci U S A ; 118(8)2021 02 23.
Artículo en Inglés | MEDLINE | ID: mdl-33536313

RESUMEN

The characterization of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral kinetics in hospitalized patients and its association with mortality is unknown. We analyzed death and nasopharyngeal viral kinetics in 655 hospitalized patients from the prospective French COVID cohort. The model predicted a median peak viral load that coincided with symptom onset. Patients with age ≥65 y had a smaller loss rate of infected cells, leading to a delayed median time to viral clearance occurring 16 d after symptom onset as compared to 13 d in younger patients (P < 10-4). In multivariate analysis, the risk factors associated with mortality were age ≥65 y, male gender, and presence of chronic pulmonary disease (hazard ratio [HR] > 2.0). Using a joint model, viral dynamics after hospital admission was an independent predictor of mortality (HR = 1.31, P < 10-3). Finally, we used our model to simulate the effects of effective pharmacological interventions on time to viral clearance and mortality. A treatment able to reduce viral production by 90% upon hospital admission would shorten the time to viral clearance by 2.0 and 2.9 d in patients of age <65 y and ≥65 y, respectively. Assuming that the association between viral dynamics and mortality would remain similar to that observed in our population, this could translate into a reduction of mortality from 19 to 14% in patients of age ≥65 y with risk factors. Our results show that viral dynamics is associated with mortality in hospitalized patients. Strategies aiming to reduce viral load could have an effect on mortality rate in this population.


Asunto(s)
/mortalidad , Modelos Teóricos , Nasofaringe/virología , ARN Viral/análisis , Carga Viral , Anciano , Anticuerpos Antivirales/sangre , /epidemiología , Femenino , Francia/epidemiología , Hospitalización , Humanos , Cinética , Masculino , Pronóstico , Estudios Prospectivos , ARN Viral/genética , Factores de Riesgo , Tasa de Supervivencia
18.
Anal Chem ; 93(8): 4126-4133, 2021 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-33570401

RESUMEN

The outbreak of the pandemic caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) calls for an urgent unmet need for developing a facial and cost-effective detection method. The requirement of well-trained personnel and sophisticated instrument of current primary mean (reverse transcription polymerase chain reaction, RT-PCR) may hinder the practical application worldwide. In this regard, a reverse transcription recombinase polymerase amplification (RT-RPA) coupled with CRISPR-Cas12a colorimetric assay is proposed for the SARS-CoV-2 detection. The methodology we have described herein utilizes DNA-modified gold nanoparticles (AuNPs) as a universal colorimetric readout and can specifically target ORF1ab and N regions of the SARS-CoV-2 genome. After the virus genome is amplified through RT-RPA, the resulting abundant dsDNA will bind and activate Cas12a. Under trans-cleavage degradation, the capped DNA substrate will be hydrolyzed gradually from AuNPs, demonstrating a change in the surface plasmon resonance (SPR), which can be facially monitored by UV-vis absorbance spectroscopy and naked eye observation. The high amplification efficiency from RT-RPA and Cas12a trans-cleavage process bring the sensitivity of our method to 1 copy of viral genome sequence per test. Notably, under the dual variations inspecting from the isothermal amplification and Cas12a activation process, the false positive events from other beta coronavirus members can be effectively avoided and thus significantly improve the specificity. Furthermore, the reliability of this colorimetric assay is validated by standard clinical samples from the hospital laboratory department. Through integration of the inherently high sensitivity and specificity from an RPA-coupled Cas12a system with the intrinsic simplicity of AuNP-based colorimetric assay, our method increases the practical testing availability of SARS-CoV-2.


Asunto(s)
Sistemas CRISPR-Cas , Colorimetría/métodos , ADN/química , Técnicas de Amplificación de Ácido Nucleico/métodos , ARN Viral/análisis , /aislamiento & purificación , Proteínas Bacterianas , Secuencia de Bases , Proteínas Asociadas a CRISPR , ADN/genética , Endodesoxirribonucleasas , Oro/química , Humanos , Nanopartículas del Metal/química , Fosfoproteínas/genética , Poliproteínas/genética , ARN Viral/genética , Transcripción Reversa , Resonancia por Plasmón de Superficie , Proteínas Virales/genética
20.
Euro Surveill ; 26(5)2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33541485

RESUMEN

In June-November 2020, SARS-CoV-2-infected mink were detected in 290 of 1,147 Danish mink farms. In North Denmark Region, 30% (324/1,092) of people found connected to mink farms tested SARS-CoV-2-PCR-positive and approximately 27% (95% confidence interval (CI): 25-30) of SARS-CoV-2-strains from humans in the community were mink-associated. Measures proved insufficient to mitigate spread. On 4 November, the government ordered culling of all Danish mink. Farmed mink constitute a potential virus reservoir challenging pandemic control.


Asunto(s)
Animales Salvajes/virología , /veterinaria , Brotes de Enfermedades/veterinaria , Reservorios de Enfermedades/veterinaria , Transmisión de Enfermedad Infecciosa/veterinaria , Visón/virología , Pandemias/veterinaria , /aislamiento & purificación , /transmisión , Animales , /virología , Dinamarca/epidemiología , Brotes de Enfermedades/estadística & datos numéricos , Reservorios de Enfermedades/virología , Granjas , Genes Virales , Humanos , Incidencia , Reacción en Cadena de la Polimerasa , Salud Pública , ARN Viral/análisis , ARN Viral/genética , /virología , Secuenciación Completa del Genoma , Zoonosis/transmisión , Zoonosis/virología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...