Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 153
Filter
1.
European Review for Medical and Pharmacological Sciences ; JOUR(15):5367-5371, 26.
Article in English | Web of Science | ID: covidwho-2081696

ABSTRACT

OBJECTIVE: Infectious bronchi-tis virus (IBV), for which no effective drugs are available, is among the most important causes of economic loss within the poultry industry. Apigenin is a flavonoid that can be isolated from plants. Apigenin has low toxicity with anti-viral activity. However, the effects of apigenin against IBV remain unclear. MATERIALS AND METHODS: Thus, here we investigate the anti-viral effect of apigenin on IBV using 10 day-old embryonated eggs by determining the virus titer by embryo infective doses50 (EID50/mL) and determining IBV genomes copy number (per mu L) of allantoic fluid. RESULTS: We found that apigenin protected embryonated eggs from IBV. Additionally, apigenin reduced the log titer of the IBV with a significant correlation of up to 9.4 times at 2 mu g/ egg. Also, apigenin appears to significantly re-duce IBV genomes copy number (per mu L) in the allantoic fluid. CONCLUSIONS: Apigenin may be a promising approach for the treatment of IBV, since it protects embryonated eggs from IBV in ovo and suppresses viral replication.

2.
The British Journal of Nutrition ; 128(8):1459-1469, 2022.
Article in English | ProQuest Central | ID: covidwho-2062085

ABSTRACT

Vitamin D is both a nutrient and a neurologic hormone that plays a critical role in modulating immune responses. While low levels of vitamin D are associated with increased susceptibility to infections and immune-related disorders, vitamin D supplementation has demonstrated immunomodulatory effects that can be protective against various diseases and infections. Vitamin D receptor is expressed in immune cells that have the ability to synthesise the active vitamin D metabolite. Thus, vitamin D acts in an autocrine manner in a local immunologic milieu in fighting against infections. Nutrigenetics and nutrigenomics are the new disciplines of nutritional science that explore the interaction between nutrients and genes using distinct approaches to decipher the mechanisms by which nutrients can influence disease development. Though molecular and observational studies have proved the immunomodulatory effects of vitamin D, only very few studies have documented the molecular insights of vitamin D supplementation. Until recently, researchers have investigated only a few selected genes involved in the vitamin D metabolic pathway that may influence the response to vitamin D supplementation and possibly disease risk. This review summarises the impact of vitamin D supplementation on immune markers from nutrigenetics and nutrigenomics perspective based on evidence collected through a structured search using PubMed, EMBASE, Science Direct and Web of Science. The research gaps and shortcomings from the existing data and future research direction of vitamin D supplementation on various immune-related disorders are discussed.

3.
Virus Evolution ; 8(veac080), 2022.
Article in English | CAB Abstracts | ID: covidwho-2051563

ABSTRACT

The first SARS-CoV-2 variant of concern (VOC) to be designated was lineage B.1.1.7, later labelled by the World Health Organization as Alpha. Originating in early autumn but discovered in December 2020, it spread rapidly and caused large waves of infections worldwide. The Alpha variant is notable for being defined by a long ancestral phylogenetic branch with an increased evolutionary rate, along which only two sequences have been sampled. Alpha genomes comprise a well-supported monophyletic clade within which the evolutionary rate is typical of SARS-CoV-2. The Alpha epidemic continued to grow despite the continued restrictions on social mixing across the UK and the imposition of new restrictions, in particular, the English national lockdown in November 2020. While these interventions succeeded in reducing the absolute number of cases, the impact of these non-pharmaceutical interventions was predominantly to drive the decline of the SARS-CoV-2 lineages that preceded Alpha. We investigate the only two sampled sequences that fall on the branch ancestral to Alpha. We find that one is likely to be a true intermediate sequence, providing information about the order of mutational events that led to Alpha. We explore alternate hypotheses that can explain how Alpha acquired a large number of mutations yet remained largely unobserved in a region of high genomic surveillance: an under-sampled geographical location, a non-human animal population, or a chronically infected individual. We conclude that the latter provides the best explanation of the observed behaviour and dynamics of the variant, although the individual need not be immunocompromised, as persistently infected immunocompetent hosts also display a higher within-host rate of evolution. Finally, we compare the ancestral branches and mutation profiles of other VOCs and find that Delta appears to be an outlier both in terms of the genomic locations of its defining mutations and a lack of the rapid evolutionary rate on its ancestral branch. As new variants, such as Omicron, continue to evolve (potentially through similar mechanisms), it remains important to investigate the origins of other variants to identify ways to potentially disrupt their evolution and emergence.

4.
New Disease Reports ; 46(1), 2022.
Article in English | ProQuest Central | ID: covidwho-2047849

ABSTRACT

Genome studies in Australia reported a novel virus, Phasey bean mild yellows virus (genus Polerovirus;PBMYV), in mixed infections with Bean leaf roll virus, Faba bean polerovirus 1, Soybean dwarf virus and Turnip yellows virus naturally infecting phasey bean (Macroptilium lathyroides) (Sharman et al., 2021). Symptoms observed on groundnut in Kenya included mild chlorosis, chlorotic mottling and spots, interveinal chlorosis, reddening and thickening of the leaves, leaf curling and bunching, reduced leaf size and stunting A total of 673 leaf samples were collected, pooled into one sample then sequenced on the MiSeq platform (Illumina, USA). The British Society for Plant Pathology Covid-19 PhD Student Support;COmmunity Network for africaN vECTor borne plant viruses (CONNECTED) training grant;Masinde Muliro University of Science and Technology Second University Innovation Fund;and the JR Biotek Foundation Plant Molecular Biology and Agricultural Research Capacity Building Program.

5.
Zhongguo Bingdubing Zazhi = Chinese Journal of Viral Diseases ; - (4):284, 2022.
Article in English | ProQuest Central | ID: covidwho-2040496

ABSTRACT

Objective To understand the genomic characteristics of SARS-CoV-2 from 40 imported cases with confirmed COVID-19 in Sichuan during January and March 2022. Methods Total viral RNA was extracted from respiratory samples of 182 confirmed COVID-19 cases who entered China through Chendu International Airport from January to March 2022.Mutation nucleic acid detection kit was used to identify the mutant strains and Illumina sequencing platform was applied for whole genome sequence(WGS) of virus.SARS-CoV-2 reference sequences were downloaded from NCBI database for genetic evolution and antigen variation analysis.The Nextclade and Pangolin online virus analysis platform were used to determine the virus family and type,and to analyze the mutation loci of the virus.The phylogenetic tree was constructed,along with the epidemiological data of cases to analyze the source and correlation of viruses. Results Among 182 imported COVID-19 cases,B.1.617.2 mutations were identified in 3 cases and B.1.1.529 mutations were detected in 57 cases.A total of 40 SARS-CoV-2 whole genome sequences with coverage>95% were obtained in this study.Nextclade typing analysis showed that 3 sequences belonged to 21J(Delta),5 sequences belonged to 21K(Omicron)and the remaining 32 sequences belonged to 21L(Omicron).Pangolin typing analysis showed that the 3 sequences of 21J(Delta)belonged to AY.4,AY.109and B.1.617.2,the 5sequences of 21K(Omicron)all belonged to BA.1.1,and the remaining 32 sequences of 21L(Omicron)belonged to BA.2.Our sequence results were99.7% consistency with the Omicron variants sequences in current GISAID database.Compared with the reference sequence strain Wuhan-Hu-1(NC_045512.2),45,47and 42nucleotide variation sites and 36,25 and 36amino acid variation sites were found in the 3 sequences of 21J(Delta).There were average 59(26-64)nucleotide mutation sites and 48(10-53)amino acid mutation sites in the 5sequences of 21K(Omicron).The median number of nucleotide mutation sites of 71(66-76)and amino acid mutation sites of 53(40-56)were identified in the 32sequences of 21L(Omicron).Phylogenetic tree analysis showed that 40SARS-CoV-2WGSs were all related to the current variants of concern(VOC). Conclusions Continuous sequencing of SARS-CoV-2whole genome from imported cases with confirmed COVID-19is of great significance for the prevention and control of the outbreak and prevalence of local epidemic caused by imported viruses in Sichuan.

6.
Chinese Journal of Virology ; 36(6):1014-1019, 2020.
Article in Chinese | GIM | ID: covidwho-2040439

ABSTRACT

SARS-CoV-2 is an RNA virus, and has a high mutation rate. The outbreak of coronavirus disease 2019 (COVID-19) began in Wuhan, Hubei Province, China in December 2019. Since then, a certain number of mutations have occurred in the SARS -CoV -2 genorne. These mutations can be classified by phylogenetic analyses to help find the infection source. However, the overall mutation rate is low, and the structure of a phylogenetic tree constructed by a single algorithm is not sufficiently reliable. To improve the reliability of classification, Paup, MrBayes, and MEGA were used to construct phylogenetic trees by different: lgorithms to analyze the genomes of all SARS-CoV-2 viruses in GenBank. In all phylogenetic trees, some sequences were clustered together in a similar pattern that coincided with the intersection of virus hosts. By comparing and analyzing similar structures between multiple phylogenetic trees, some information about the infection source was revealed. As SARS-CoV-2 evolves and genomic databases become enriched, the method of screening will provide increasingly useful information about infection sources and pathways.

7.
International Journal of Intelligent Computing and Cybernetics ; 15(4):589-598, 2022.
Article in English | ProQuest Central | ID: covidwho-2037682

ABSTRACT

Purpose>Patient treatment trajectory data are used to predict the outcome of the treatment to particular disease that has been carried out in the research. In order to determine the evolving disease on the patient and changes in the health due to treatment has not considered existing methodologies. Hence deep learning models to trajectory data mining can be employed to identify disease prediction with high accuracy and less computation cost.Design/methodology/approach>Multifocus deep neural network classifiers has been utilized to detect the novel disease class and comorbidity class to the changes in the genome pattern of the patient trajectory data can be identified on the layers of the architecture. Classifier is employed to learn extracted feature set with activation and weight function and then merged on many aspects to classify the undetermined sequence of diseases as a new variant. The performance of disease progression learning progress utilizes the precision of the constituent classifiers, which usually has larger generalization benefits than those optimized classifiers.Findings>Deep learning architecture uses weight function, bias function on input layers and max pooling. Outcome of the input layer has applied to hidden layer to generate the multifocus characteristics of the disease, and multifocus characterized disease is processed in activation function using ReLu function along hyper parameter tuning which produces the effective outcome in the output layer of a fully connected network. Experimental results have proved using cross validation that proposed model outperforms methodologies in terms of computation time and accuracy.Originality/value>Proposed evolving classifier represented as a robust architecture on using objective function to map the data sequence into a class distribution of the evolving disease class to the patient trajectory. Then, the generative output layer of the proposed model produces the progression outcome of the disease of the particular patient trajectory. The model tries to produce the accurate prognosis outcomes by employing data conditional probability function. The originality of the work defines 70% and comparisons of the previous methods the method of values are accurate and increased analysis of the predictions.

8.
Journal of Biotech Research ; 13:177-188, 2022.
Article in English | ProQuest Central | ID: covidwho-2033805

ABSTRACT

The 3C protease is distinguished from most proteases due to the presence of cysteine nucleophile that plays an essential role in viral replication. This peculiar structure encompassed with its role in viral replication has promoted 3C protease as an interesting target for therapeutic agents in the treatment of diseases caused by human rhinovirus (HRV). However, the molecular mechanisms surrounding the chirality of inhibitors of HRV 3C protease remain unresolved. Herein using in silico techniques such molecular dynamic simulation and binding free estimations via molecular mechanics poisson-boltzmann surface area (MM/PBSA), we present a comprehensive molecular dynamics study of the comparison of two potent inhibitors, SG85 and rupintrivir, complexed with HRV3C protease. The binding free energy studies revealed a higher binding affinity for SG85 of 58.853 kcal/mol than that for rupintrivir of 54.0873 kcal/mol and this was found to be in correlation with the experimental data. The energy decomposition analysis showed that residues Leu 127, Thr 142, Ser 144, Gly 145, Tyr 146, Cys 147, His 161, Val 162, Gly 163, Gly 164, Asn 165, and Phe 170 largely contributed to the binding of SG85, whereas His 40, Leu 127, and Gly 163 impacted the binding of rupintrivir. The results further showed that His 40, Glu 71, Leu 127, Cys 147, Gly 163, and Gyl 164 were crucial residues that played a key role in ligand-enzyme binding, and amongst these crucial residues, His 40, Glu 71, and Cys 147 appeared to be conserved in the active site of HRV-3C protease when bound by both inhibitors. These findings provided a comprehensive understanding of the dynamics and structural features and would serve as guidance in the design and development of potent novel inhibitors of HRV.

9.
Zoonoses ; 1(13), 2021.
Article in English | CAB Abstracts | ID: covidwho-2025746

ABSTRACT

As the novel coronavirus SARS-CoV-2 spread around the world, multiple waves of variants emerged, thus leading to local or global population shifts during the pandemic. A new variant named Omicron (PANGO lineage B.1.1.529), which was first discovered in southern Africa, has recently been proposed by the World Health Organization to be a Variant of Concern. This variant carries an unusually large number of mutations, particularly on the spike protein and receptor binding domain, in contrast to other known major variants. Some mutation sites are associated with enhanced viral transmission, infectivity, and pathogenicity, thus enabling the virus to evade the immune protective barrier. Given that the emergence of the Omicron variant was accompanied by a sharp increase in infection cases in South Africa, the variant has the potential to trigger a new global epidemic peak. Therefore, continual attention and a rapid response are required to decrease the possible risks to public health.

10.
Water ; 14(16):2491, 2022.
Article in English | ProQuest Central | ID: covidwho-2024373

ABSTRACT

In 2014, Oxford Nanopore Technologies (ONT) introduced an affordable and portable sequencer called MinION. We reviewed emerging applications in water research and assessed progress made with this platform towards ubiquitous genetics. With >99% savings in upfront costs as compared to conventional platforms, the MinION put sequencing capacity into the hands of many researchers and enabled novel applications with diverse remits, including in countries without universal access to safe water and sanitation. However, to realize the MinION’s fabled portability, all the auxiliary equipment items for biomass concentration, genetic material extraction, cleanup, quantification, and sequencing library preparation also need to be lightweight and affordable. Only a few studies demonstrated fully portable workflows by using the MinION onboard a diving vessel, an oceanographic research ship, and at sewage treatment works. Lower nanopore sequencing read accuracy as compared to alternative platforms currently hinders MinION applications beyond research, and inclusion of positive and negative controls should become standard practice. ONT’s EPI2ME platform is a major step towards user-friendly bioinformatics. However, no consensus has yet emerged regarding the most appropriate bioinformatic pipeline, which hinders intercomparison of study results. Processing, storing, and interpreting large data sets remains a major challenge for ubiquitous genetics and democratizing sequencing applications.

11.
Frontiers in Ecology and Evolution ; 10, 2022.
Article in English | Web of Science | ID: covidwho-2022693

ABSTRACT

Animal specimens in natural history collections are invaluable resources in examining the historical context of pathogen dynamics in wildlife and spillovers to humans. For example, natural history specimens may reveal new associations between bat species and coronaviruses. However, RNA viruses are difficult to study in historical specimens because protocols for extracting RNA from these specimens have not been optimized. Advances have been made in our ability to recover nucleic acids from formalin-fixed paraffin-embedded samples (FFPE) commonly used in human clinical studies, yet other types of formalin preserved samples have received less attention. Here, we optimize the recovery of RNA from formalin-fixed ethanol-preserved museum specimens in order to improve the usability of these specimens in surveys for zoonotic diseases. We provide RNA quality and quantity measures for replicate tissues subsamples of 22 bat specimens from five bat genera (Rhinolophus, Hipposideros, Megareops, Cynopterus, and Nyctalus) collected in China and Myanmar from 1886 to 2003. As tissues from a single bat specimen were preserved in a variety of ways, including formalin-fixed (8 bats), ethanol-preserved and frozen (13 bats), and flash frozen (2 bats), we were able to compare RNA quality and yield across different preservation methods. RNA extracted from historical museum specimens is highly fragmented, but usable for short-read sequencing and targeted amplification. Incubation of formalin-fixed samples with Proteinase-K following thorough homogenization improves RNA yield. This optimized protocol extends the types of data that can be derived from existing museum specimens and facilitates future examinations of host and pathogen RNA from specimens.

12.
Nature ; 609(7925):12, 2022.
Article in English | ProQuest Central | ID: covidwho-2016626
13.
Strategic Studies Quarterly ; 15(3):6-33, 2021.
Article in English | ProQuest Central | ID: covidwho-2010943

ABSTRACT

This article considers the prospect and potential of genetic warfare. Drawing on expert interviews and fieldwork, it begins by detailing how the recent and anticipated innovations in synthetic biology, artificial intelligence, and nanotechnology solve the weaponization, delivery, and precision problems that had previously made biological weapons impractical. The article then considers how states and non-state actors may develop and use genetic weapons, with a focus on the problem of secrecy. Underlying whether to reveal or conceal genetic war capability is a trade-off between strategic surprise and deterrence. Actors requiring deterrence are likely to reveal genetic military capability. With the only rivaling source of deterrence being nuclear weapons, nonnuclear states and non-state actors are more likely to make public their genetic weapons capability than nuclear states. The question of whether to use genetic weapons covertly or openly also entails a trade-off. Covert use confers strategic and tactical benefits, whereas the benefits of unrestricted use are primarily psychological. Terroristic, genocidal, and apocalyptic regimes and non-state actors may use genetic weapons openly, but most would likely opt for covert genetic warfare.

14.
Health Science Journal ; 16:1-6, 2022.
Article in English | ProQuest Central | ID: covidwho-2002884

ABSTRACT

Iphsj-22-12747(R);Published: 09-Jun-2022, DOI: 10.36648/1791809X.16.S7.948 Introduction The disease caused by a B-coronavirus, an RNA virus, had its beginnings in 2019 in Wuhan - China where a series of cases of pneumonia caused by this agent were identified, currently six serotypes that produce diseases in humans are known., four of these are prevalent and cause typical cold symptoms, the remaining two are responsible for the appearance of severe acute respiratory syndrome SarsCoV and Middle East respiratory syndrome MERS-CoV;After nucleic acid sequencing of lower respiratory tract epithelial cells from 4 patients with confirmed pneumonia of unknown cause by real-time reverse transcription PCR at Beijing Hospital, a novel 2019-nCoV beta coronavirus was found, which was then was called SARS-CoV-2, also giving as a result that this new virus has information from the subgenus Sarbecovirus, of the Orthocoronavirinae family, which makes it different from SARS-CoV and MERS-CoV, however according to various reports it was identified that the genome of SARS-Co V-2, is between 75% and 80% identical to SARS-CoV and therefore its name, SARS-CoV-2 belongs to this genus of coronavirus and its genome consists of a single-stranded RNA 29 kb in length. The last protein is present inside the virion and is associated with the viral RNA, and the other 3 proteins are associated with the external structure of the virus, this disease causing the current pandemic of global importance is characterized by affinity to the respiratory system has characteristics important as the production of increased pro-inflammatory cytokines and a decrease in the response of T cells, which is directly related to inflammation and severe lung damage that occurs in patients infected with SarsCoV2, also highlighting the onset of given symptoms from 5 days, the incubation period of approximately 14 days and the high transmission capacity of the virus given by various mechanisms such as droplet transmission (given when the infected person coughs or sneezes and these droplets released by this mechanism are inhaled by the people nearby), by contact (when an individual has direct contact with contaminated surfaces). inhaled and then passes these through the eyes and mouth) and by aerosols (this occurs when the respiratory droplets of the infected are in contact with the environment in places with little ventilation or closed that when inhaled cause infection), in addition From this, manifestations and alterations have been found in the gastrointestinal area, since enterocytes with high expression of ACE II receptors have been found in this area, which is why fecal transmission is also described in a smaller proportion and less frequently (1). Some monoclonal antibodies are currently used to treat COVID-19, standing out in this group itolizumab and tocilizumab, the group's mechanism of action is based on the fact that monoclonal antibodies bind to target molecules, which can be surface membrane receptors, proteins associated with enzymatic systems or circulating proteins, which produces direct or indirect effects on tissue function, where virus neutralization occurs when a sufficient number of epitopes (antigenic determinant is the portion of a macromolecule that is recognized by the immune system, specifically the sequence to which antibodies bind, B cell receptors or T cell receptors.) on the surface of the virus are occupied by antibodies. Severe Acute Respiratory Syndrome;Viral pneumonia;Coronavirus infections;Antibodies;Cytokines;lymphocytes;Vaccines;COVID-19 treatment and or. [...]including all the documents that will deal with the use of anti-mononuclear antibodies as a therapy for Covid-19, the data found was between 16-28 records, thus using 22 articles for the preparation of this document.

15.
SciDev.net ; 2022.
Article in English | ProQuest Central | ID: covidwho-1998629

ABSTRACT

Speed read Genomics has been crucial in COVID-19 response, driving research But many poor countries lack access to the technology First WHO Science Council report makes recommendations to address barriers The World Health Organization (WHO) has issued an urgent call to accelerate access to genomics, especially in resource-poor countries, in a report that examines technology gaps and opportunities. Genomics is the branch of science that uses methods from biochemistry, genetics, and molecular biology to understand and use biological information in DNA and RNA to benefit medicine and public health — but the technology can also be used in agricultural research. While genomics technology is driving some of the most ground-breaking research in medical science, including COVID-19 vaccine research and development, its full potential is yet to be realised globally, especially in low- and middle-income countries (LMICs), according to the WHO Science Council’s inaugural report.

16.
SciDev.net ; 2021.
Article in English | ProQuest Central | ID: covidwho-1998385

ABSTRACT

According to the United Nations High Commissioner for Refugees (UNHCR), conflicts in the region have left around 17 million refugees. How could the WHO approve the vaccine when clinical trials didn’t target a significant number of people and when, according to a document published by Reuters, some WHO experts were sceptical? There have also been some trials on people above 60 years old but on a smaller number, so it is hard to measure the efficacy for this group. [...]WHO recommends that countries using the vaccine should monitor its safety and efficacy.

17.
SciDev.net ; 2022.
Article in English | ProQuest Central | ID: covidwho-1999222

ABSTRACT

Speed read A project is aiding resource-limited scientists to analyse deadly microbes’ genetic materials Large collections can now be analysed for as little as US$10 per genome Affordable genomic analysis is key to tackling infectious diseases [NAIROBI] A project equipping researchers with cheap and accessible methods for studying genetic materials of large collections of bacteria that cause diseases could be critical in tackling future global health challenges, scientists say. According to researchers, large-scale bacterial genome analyses have been possible in only a few sequencing centres globally until now and the cost had been as much as US$100 per genome. See PDF] “Our project has provided the best understanding of the Salmonella variants responsible for bloodstream infections in African countries including Democratic Republic of Congo, Gambia, Mali, Malawi, Kenya, Senegal and Uganda in recent years — information that will be invaluable for evaluating the impact of the [Salmonella] vaccine rollout,” Hinton explained.

18.
Chinese Journal of Virology ; 36(3):365-370, 2020.
Article in Chinese | GIM | ID: covidwho-1994547

ABSTRACT

"Novel coronavirus 2019" (which was renamed subsequently "severe acute respiratory syndrome coronavirus-2" (SARS-CoV-2) on 11 February 2020) caused a pneumonia outbreak in Wuhan (Hubei Province, China) in December 2019. In our previous studies, two important findings regarding SARS-CoV-2 were reported, for the first time, on 21 January 2020: (1) multiple alternative translations of a coding sequence in genomes of betacoronavirus subgroup B;(2) a novel mutation in the spike (S) proteins of betacoronavirus. By this mutation, SARS-CoV-2 acquired a cleavage site for the furin enzyme in its S protein, which is not present in the S proteins of most other betacoronaviruses (e.g. SARS-CoV). In the present study, we performed analyses of 5' untranslated regions (UTRs) in betacoronavirus. Using 5' UTR barcodes, 1,265 betacoronaviruses were clustered into four classes, and viruses in each class had similar virulence. The class 1, 2, 3 and 4 match the subgroup C, B, A and D of betacoronavirus, respectively. In particular, SARS-CoV-2 and SARS-CoV have the same 5' UTR barcode. As the main contribution of the present study, we developed 5' UTR barcoding to be used in the detection, identification, classification and phylogenetic analysis of, but not limited to coronavirus. Our method is very useful for early-warning, prevention and control of coronavirus. We found that Internal Ribosome Entry Sites (IRESs) may have important roles in the virulence of betacoronavirus. This important finding is reported, for the first time, to understand the virulence of SARS-CoV-2 at the molecular level. This finding can be used directly for vaccine development and design of drugs against SARS-CoV-2, but such development is not limited to coronavirus only. In addition, we propose that the upstream hairpin structures neighboring the start codons in mRNAs have important roles in protein translation in eukaryotes.

19.
Chinese Journal of Virology ; 36(3):371-376, 2020.
Article in Chinese | GIM | ID: covidwho-1994546

ABSTRACT

A Taqman qRT-PCR method for detection of Nipah virus (NiV) N gene was established and applied to the detection and quantification of NiV samples. Primers and probe were designed based on the conserved region of NiV N gene, and a Taqman qRT-PCR detection method was established. The sensitivity, specificity, and repeatability of the method were analyzed, and the method was used for sample detection. The analytical detection limit of this Taqman qRT-PCR method established in this study was 102 copies/pL and allowed quantitation ranging from 1.0 x 109 to 1.0 x 102 copies /L. This method showed good specificity and repeatability. NiV Malaysia strain and Bangladesh strain could be effectively detected by the Taqman qRT- PCR. 50 it can be used for the detection and quantification of NiV samples.

20.
Angewandte Chemie ; 134(32), 2022.
Article in English | ProQuest Central | ID: covidwho-1981566

ABSTRACT

The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR‐associated (Cas) systems have recently received notable attention for their applications in nucleic acid detection. Despite many attempts, the majority of current CRISPR‐based biosensors in infectious respiratory disease diagnostic applications still require target preamplifications. This study reports a new biosensor for amplification‐free nucleic acid detection via harnessing the trans‐cleavage mechanism of Cas13a and ultrasensitive graphene field‐effect transistors (gFETs). CRISPR Cas13a‐gFET achieves the detection of SARS‐CoV‐2 and respiratory syncytial virus (RSV) genome down to 1 attomolar without target preamplifications. Additionally, we validate the detection performance using clinical SARS‐CoV‐2 samples, including those with low viral loads (Ct value >30). Overall, these findings establish our CRISPR Cas13a‐gFET among the most sensitive amplification‐free nucleic acid diagnostic platforms to date.

SELECTION OF CITATIONS
SEARCH DETAIL