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1.
Microbiol Spectr ; 10(4): e0066022, 2022 08 31.
Article in English | MEDLINE | ID: covidwho-2193508

ABSTRACT

Shiga toxin-producing Escherichia coli (STEC) infection can cause mild to severe illness, such as nonbloody or bloody diarrhea, and the fatal hemolytic uremic syndrome (HUS). The molecular mechanism underlying the variable pathogenicity of STEC infection is not fully defined so far. Here, we performed a comparative genomics study on a large collection of clinical STEC strains collected from STEC-infected pediatric patients with and without HUS in Finland over a 16-year period, aiming to identify the bacterial genetic factors that can predict the risk to cause HUS and poor renal outcome. Of 240 STEC strains included in this study, 52 (21.7%) were from pediatric patients with HUS. Serotype O157:H7 was the main cause of HUS, and Shiga toxin gene subtype stx2a was significantly associated with HUS. Comparative genomics and pangenome-wide association studies identified a number of virulence and accessory genes overrepresented in HUS-associated STEC compared to non-HUS STEC strains, including genes encoding cytolethal distending toxins, type III secretion system effectors, adherence factors, etc. No virulence or accessory gene was significantly associated with risk factors for poor renal outcome among HUS patients assessed in this study, including need for and duration of dialysis, presence and duration of anuria, and leukocyte counts. Whole-genome phylogeny and multiple-correspondence analysis of pangenomes could not separate HUS STEC from non-HUS STEC strains, suggesting that STEC strains with diverse genetic backgrounds may independently acquire genetic elements that determine their varied pathogenicity. Our findings indicate that nonbacterial factors, i.e., characteristics of the host immunity, might affect STEC virulence and clinical outcomes. IMPORTANCE Shiga toxin-producing Escherichia coli (STEC) is a serious public health burden worldwide which causes outbreaks of gastrointestinal diseases and the fatal hemolytic uremic syndrome (HUS) characterized by the triad of mechanical hemolytic anemia, thrombocytopenia, and acute renal failure. Understanding the mechanism underlying the disease severity and patient outcome is of high importance. Using comparative genomics on a large collection of clinical STEC strains from STEC-infected patients with and without HUS, our study provides a reference of STEC genetic factors/variants that can be used as predictors of the development of HUS, which will aid risk assessment at the early stage of STEC infection. Additionally, our findings suggest that nonbacterial factors may play a primary role in the renal outcome in STEC-infected patients with HUS; further studies are needed to validate this.


Subject(s)
Escherichia coli Infections , Hemolytic-Uremic Syndrome , Shiga-Toxigenic Escherichia coli , Child , Escherichia coli Infections/epidemiology , Escherichia coli Infections/microbiology , Finland/epidemiology , Genomics , Hemolytic-Uremic Syndrome/epidemiology , Hemolytic-Uremic Syndrome/microbiology , Humans , Shiga Toxin , Shiga-Toxigenic Escherichia coli/genetics
2.
Theranostics ; 12(10): 4779-4790, 2022.
Article in English | MEDLINE | ID: covidwho-2203050

ABSTRACT

New variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are continuing to spread globally, contributing to the persistence of the COVID-19 pandemic. Increasing resources have been focused on developing vaccines and therapeutics that target the Spike glycoprotein of SARS-CoV-2. Recent advances in microfluidics have the potential to recapitulate viral infection in the organ-specific platforms, known as organ-on-a-chip (OoC), in which binding of SARS-CoV-2 Spike protein to the angiotensin-converting enzyme 2 (ACE2) of the host cells occurs. As the COVID-19 pandemic lingers, there remains an unmet need to screen emerging mutations, to predict viral transmissibility and pathogenicity, and to assess the strength of neutralizing antibodies following vaccination or reinfection. Conventional detection of SARS-CoV-2 variants relies on two-dimensional (2-D) cell culture methods, whereas simulating the micro-environment requires three-dimensional (3-D) systems. To this end, analyzing SARS-CoV-2-mediated pathogenicity via microfluidic platforms minimizes the experimental cost, duration, and optimization needed for animal studies, and obviates the ethical concerns associated with the use of primates. In this context, this review highlights the state-of-the-art strategy to engineer the nano-liposomes that can be conjugated with SARS-CoV-2 Spike mutations or genomic sequences in the microfluidic platforms; thereby, allowing for screening the rising SARS-CoV-2 variants and predicting COVID-19-associated coagulation. Furthermore, introducing viral genomics to the patient-specific blood accelerates the discovery of therapeutic targets in the face of evolving viral variants, including B1.1.7 (Alpha), B.1.351 (Beta), B.1.617.2 (Delta), c.37 (Lambda), and B.1.1.529 (Omicron). Thus, engineering nano-liposomes to encapsulate SARS-CoV-2 viral genomic sequences enables rapid detection of SARS-CoV-2 variants in the long COVID-19 era.


Subject(s)
COVID-19 , Coronavirus Infections , Pneumonia, Viral , Animals , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/complications , COVID-19/diagnosis , Coronavirus Infections/prevention & control , Genomics , Humans , Liposomes , Microfluidics , Mutation , Pandemics/prevention & control , Peptidyl-Dipeptidase A/metabolism , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus
4.
Euro Surveill ; 27(43)2022 10.
Article in English | MEDLINE | ID: covidwho-2154580

ABSTRACT

BackgroundTracking person-to-person SARS-CoV-2 transmission in the population is important to understand the epidemiology of community transmission and may contribute to the containment of SARS-CoV-2. Neither contact tracing nor genomic surveillance alone, however, are typically sufficient to achieve this objective.AimWe demonstrate the successful application of the integrated genomic surveillance (IGS) system of the German city of Düsseldorf for tracing SARS-CoV-2 transmission chains in the population as well as detecting and investigating travel-associated SARS-CoV-2 infection clusters.MethodsGenomic surveillance, phylogenetic analysis, and structured case interviews were integrated to elucidate two genetically defined clusters of SARS-CoV-2 isolates detected by IGS in Düsseldorf in July 2021.ResultsCluster 1 (n = 67 Düsseldorf cases) and Cluster 2 (n = 36) were detected in a surveillance dataset of 518 high-quality SARS-CoV-2 genomes from Düsseldorf (53% of total cases, sampled mid-June to July 2021). Cluster 1 could be traced back to a complex pattern of transmission in nightlife venues following a putative importation by a SARS-CoV-2-infected return traveller (IP) in late June; 28 SARS-CoV-2 cases could be epidemiologically directly linked to IP. Supported by viral genome data from Spain, Cluster 2 was shown to represent multiple independent introduction events of a viral strain circulating in Catalonia and other European countries, followed by diffuse community transmission in Düsseldorf.ConclusionIGS enabled high-resolution tracing of SARS-CoV-2 transmission in an internationally connected city during community transmission and provided infection chain-level evidence of the downstream propagation of travel-imported SARS-CoV-2 cases.


Subject(s)
COVID-19 , Communicable Diseases, Imported , Humans , SARS-CoV-2/genetics , Travel , Communicable Diseases, Imported/epidemiology , COVID-19/epidemiology , Phylogeny , Contact Tracing , Germany/epidemiology , Genomics
5.
Lancet Glob Health ; 10(12): e1855-e1859, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-2150878

ABSTRACT

Data sharing in research is fraught with controversy. Academic success is premised on competitive advantage, with research teams protecting their research findings until publication. Research funders, by contrast, often require data sharing. Beyond traditional research and funding requirements, surveillance data have become contentious. Public health emergencies involving pathogens require intense genomic surveillance efforts and call for the rapid sharing of data on the basis of public interest. Under these circumstances, timely sharing of data becomes a matter of scientific integrity. During the COVID-19 pandemic, the transformative potential of genomic pathogen data sharing became obvious and advanced the debate on data sharing. However, when the genomic sequencing data of the omicron (B.1.1.529) variant was shared and announced by scientists in southern Africa, various challenges arose, including travel bans. The scientific, economic, and moral impact was catastrophic. Yet, travel restrictions failed to mitigate the spread of the variant already present in countries outside Africa. Public perceptions of the negative effect of data sharing are detrimental to the willingness of research participants to consent to sharing data in postpandemic research and future pandemics. Global health governance organisations have an important role in developing guidance on responsible sharing of genomic pathogen data in public health emergencies.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , Pandemics , COVID-19/epidemiology , Emergencies , Information Dissemination , Genomics , Africa, Southern
6.
Viruses ; 14(9)2022 09 14.
Article in English | MEDLINE | ID: covidwho-2143631

ABSTRACT

In this retrospective, single-center study, we conducted an analysis of 13,699 samples from different individuals obtained from the Federal Research Center of Fundamental and Translational Medicine, from 1 April to 30 May 2020 in Novosibirsk region (population 2.8 million people). We identified 6.49% positive for SARS-CoV-2 cases out of the total number of diagnostic tests, and 42% of them were from asymptomatic people. We also detected two asymptomatic people, who had no confirmed contact with patients with COVID-19. The highest percentage of positive samples was observed in the 80+ group (16.3%), while among the children and adults it did not exceed 8%. Among all the people tested, 2423 came from a total of 80 different destinations and only 27 of them were positive for SARS-CoV-2. Out of all the positive samples, 15 were taken for SARS-CoV-2 sequencing. According to the analysis of the genome sequences, the SARS-CoV-2 variants isolated in the Novosibirsk region at the beginning of the pandemic belonged to three phylogenetic lineages according to the Pangolin classification: B.1, B.1.1, and B.1.1.129. All Novosibirsk isolates contained the D614G substitution in the Spike protein, two isolates werecharacterized by an additional M153T mutation, and one isolate wascharacterized by the L5F mutation.


Subject(s)
COVID-19 , SARS-CoV-2 , Adult , COVID-19/epidemiology , Child , Genome, Viral , Genomics , Humans , Mutation , Pandemics , Phylogeny , Retrospective Studies , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics
7.
Genome Med ; 14(1): 135, 2022 Nov 28.
Article in English | MEDLINE | ID: covidwho-2139390

ABSTRACT

BACKGROUND: As circulating DNA (cirDNA) is mainly detected as mononucleosome-associated circulating DNA (mono-N cirDNA) in blood, apoptosis has until now been considered as the main source of cirDNA. The mechanism of cirDNA release into the circulation, however, is still not fully understood. This work addresses that knowledge gap, working from the postulate that neutrophil extracellular traps (NET) may be a source of cirDNA, and by investigating whether NET may directly produce mono-N cirDNA. METHODS: We studied (1) the in vitro kinetics of cell derived genomic high molecular weight (gHMW) DNA degradation in serum; (2) the production of extracellular DNA and NET markers such as neutrophil elastase (NE) and myeloperoxidase (MPO) by ex vivo activated neutrophils; and (3) the in vitro NET degradation in serum; for this, we exploited the synergistic analytical information provided by specifically quantifying DNA by qPCR, and used shallow WGS and capillary electrophoresis to perform fragment size analysis. We also performed an in vivo study in knockout mice, and an in vitro study of gHMW DNA degradation, to elucidate the role of NE and MPO in effecting DNA degradation and fragmentation. We then compared the NET-associated markers and fragmentation size profiles of cirDNA in plasma obtained from patients with inflammatory diseases found to be associated with NET formation and high levels of cirDNA (COVID-19, N = 28; systemic lupus erythematosus, N = 10; metastatic colorectal cancer, N = 10; and from healthy individuals, N = 114). RESULTS: Our studies reveal that gHMW DNA degradation in serum results in the accumulation of mono-N DNA (81.3% of the remaining DNA following 24 h incubation in serum corresponded to mono-N DNA); "ex vivo" NET formation, as demonstrated by a concurrent 5-, 5-, and 35-fold increase of NE, MPO, and cell-free DNA (cfDNA) concentration in PMA-activated neutrophil culture supernatant, leads to the release of high molecular weight DNA that degrades down to mono-N in serum; NET mainly in the form of gHMW DNA generate mono-N cirDNA (2 and 41% of the remaining DNA after 2 h in serum corresponded to 1-10 kbp fragments and mono-N, respectively) independent of any cellular process when degraded in serum; NE and MPO may contribute synergistically to NET autocatabolism, resulting in a 25-fold decrease in total DNA concentration and a DNA fragment size profile similar to that observed from cirDNA following 8 h incubation with both NE and MPO; the cirDNA size profile of NE KO mice significantly differed from that of the WT, suggesting NE involvement in DNA degradation; and a significant increase in the levels of NE, MPO, and cirDNA was detected in plasma samples from lupus, COVID-19, and mCRC, showing a high correlation with these inflammatory diseases, while no correlation of NE and MPO with cirDNA was found in HI. CONCLUSIONS: Our work describes the mechanisms by which NET and cirDNA are linked. In doing so, we demonstrate that NET are a major source of mono-N cirDNA independent of apoptosis and establish a new paradigm of the mechanisms of cirDNA release in normal and pathological conditions. We also demonstrate a link between immune response and cirDNA.


Subject(s)
COVID-19 , Cell-Free Nucleic Acids , Extracellular Traps , Animals , Mice , Neutrophils , Genomics
8.
Nat Commun ; 13(1): 7284, 2022 Nov 26.
Article in English | MEDLINE | ID: covidwho-2133432

ABSTRACT

Molnupiravir is an antiviral, currently approved by the UK Medicines and Healthcare products Regulatory Agency (MHRA) for treating at-risk COVID-19 patients, that induces lethal error catastrophe in SARS-CoV-2. How this drug-induced mechanism of action might impact the emergence of resistance mutations is unclear. To investigate this, we used samples from the AGILE Candidate Specific Trial (CST)-2 (clinical trial number NCT04746183). The primary outcomes of AGILE CST-2 were to measure the drug safety and antiviral efficacy of molnupiravir in humans (180 participants randomised 1:1 with placebo). Here, we describe the pre-specified exploratory virological endpoint of CST-2, which was to determine the possible genomic changes in SARS-CoV-2 induced by molnupiravir treatment. We use high-throughput amplicon sequencing and minor variant analysis to characterise viral genomics in each participant whose longitudinal samples (days 1, 3 and 5 post-randomisation) pass the viral genomic quality criteria (n = 59 for molnupiravir and n = 65 for placebo). Over the course of treatment, no specific mutations were associated with molnupiravir treatment. We find that molnupiravir significantly increased the transition:transversion mutation ratio in SARS-CoV-2, consistent with the model of lethal error catastrophe. This study highlights the utility of examining intra-host virus populations to strengthen the prediction, and surveillance, of potential treatment-emergent adaptations.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , COVID-19/drug therapy , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Genomics
10.
BMJ ; 379: o2643, 2022 11 24.
Article in English | MEDLINE | ID: covidwho-2137613

Subject(s)
Genomics , State Medicine , Humans
11.
Saudi Med J ; 43(11): 1276-1279, 2022 Nov.
Article in English | MEDLINE | ID: covidwho-2119223

ABSTRACT

OBJECTIVES: To investigate the emergent mutations involved in the evolutionary stages of the virus for better management of pandemic. METHODS: This cross-sectional genomic investigation was performed on February 28, 2022, at the Biology Department, Faculty of Science, Tabuk University. Numerous mutations were searched in genomic isolates of Omicron variant prevalent in the Kingdom of Saudi Arabian. Whole-genome sequences were retrieved from genomic databases and were subjected to the Global Initiative on Sharing Avian Influenza Data (GISAID) CoVsurver for the Omicron variant detection and mutations. RESULTS: Approximately 8.755 million SARS-CoV-2 genomes were reported to GISAID on February 28, 2022, of which 1270 have been reported from the Kingdom of Saudi Arabia. Among the 1270 genomes, 30 were Omicron variants. Among the Saudi Arabian genomes, 30 were detected as Omicron variants. Twenty-four unique mutations have been detected in membrane, envelope, spike and non-structural proteins (NSP) 12, NSP3, and NSP2. Ten of these unique mutations have been detected in spike protein. CONCLUSION: The current study provides useful information for further experimental investigation of mutation's effects on virus transmission, severity, and vaccine efficacy.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Animals , SARS-CoV-2/genetics , Saudi Arabia/epidemiology , Genome, Viral , Cross-Sectional Studies , COVID-19/epidemiology , Mutation , Genomics
12.
Viruses ; 14(11)2022 Nov 16.
Article in English | MEDLINE | ID: covidwho-2116125

ABSTRACT

Global SARS-CoV-2 genomic surveillance efforts have provided critical data on the ongoing evolution of the virus to inform best practices in clinical care and public health throughout the pandemic. Impactful genomic surveillance strategies generally follow a multi-disciplinary pipeline involving clinical sample collection, viral genotyping, metadata linkage, data reporting, and public health responses. Unfortunately, current limitations in each of these steps have compromised the overall effectiveness of these strategies. Biases from convenience-based sampling methods can obfuscate the true distribution of circulating variants. The lack of standardization in genotyping strategies and bioinformatic expertise can create bottlenecks in data processing and complicate interpretation. Limitations and inconsistencies in clinical and demographic data collection and sharing can slow the compilation and limit the utility of comprehensive datasets. This likewise can complicate data reporting, restricting the availability of timely data. Finally, gaps and delays in the implementation of genomic surveillance data in the public health sphere can prevent officials from formulating effective mitigation strategies to prevent outbreaks. In this review, we outline current SARS-CoV-2 global genomic surveillance methods and assess roadblocks at each step of the pipeline to identify potential solutions. Evaluating the current obstacles that impede effective surveillance can improve both global coordination efforts and pandemic preparedness for future outbreaks.


Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , COVID-19/prevention & control , SARS-CoV-2/genetics , Genomics , Pandemics/prevention & control , Public Health
13.
Proc Biol Sci ; 289(1987): 20221747, 2022 Nov 30.
Article in English | MEDLINE | ID: covidwho-2115857

ABSTRACT

The raw material for viral evolution is provided by intra-host mutations occurring during replication, transcription or post-transcription. Replication and transcription of Coronaviridae proceed through the synthesis of negative-sense 'antigenomes' acting as templates for positive-sense genomic and subgenomic RNA. Hence, mutations in the genomes of SARS-CoV-2 and other coronaviruses can occur during (and after) the synthesis of either negative-sense or positive-sense RNA, with potentially distinct patterns and consequences. We explored for the first time the mutational spectrum of SARS-CoV-2 (sub)genomic and anti(sub)genomic RNA. We use a high-quality deep sequencing dataset produced using a quantitative strand-aware sequencing method, controlled for artefacts and sequencing errors, and scrutinized for accurate detection of within-host diversity. The nucleotide differences between negative- and positive-sense strand consensus vary between patients and do not show dependence on age or sex. Similarities and differences in mutational patterns between within-host minor variants on the two RNA strands suggested strand-specific mutations or editing by host deaminases and oxidative damage. We observe generally neutral and slight negative selection on the negative strand, contrasting with purifying selection in ORF1a, ORF1b and S genes of the positive strand of the genome.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , RNA, Viral/genetics , Genome, Viral , Mutation , Genomics
14.
15.
Elife ; 112022 11 08.
Article in English | MEDLINE | ID: covidwho-2110897

ABSTRACT

Public health emergencies like SARS, MERS, and COVID-19 have prioritized surveillance of zoonotic coronaviruses, resulting in extensive genomic characterization of coronavirus diversity in bats. Sequencing viral genomes directly from animal specimens remains a laboratory challenge, however, and most bat coronaviruses have been characterized solely by PCR amplification of small regions from the best-conserved gene. This has resulted in limited phylogenetic resolution and left viral genetic factors relevant to threat assessment undescribed. In this study, we evaluated whether a technique called hybridization probe capture can achieve more extensive genome recovery from surveillance specimens. Using a custom panel of 20,000 probes, we captured and sequenced coronavirus genomic material in 21 swab specimens collected from bats in the Democratic Republic of the Congo. For 15 of these specimens, probe capture recovered more genome sequence than had been previously generated with standard amplicon sequencing protocols, providing a median 6.1-fold improvement (ranging up to 69.1-fold). Probe capture data also identified five novel alpha- and betacoronaviruses in these specimens, and their full genomes were recovered with additional deep sequencing. Based on these experiences, we discuss how probe capture could be effectively operationalized alongside other sequencing technologies for high-throughput, genomics-based discovery and surveillance of bat coronaviruses.


Subject(s)
COVID-19 , Chiroptera , Animals , Phylogeny , Genetic Variation , Sequence Analysis, DNA , Genome, Viral/genetics , High-Throughput Nucleotide Sequencing , Genomics
16.
Probl Sotsialnoi Gig Zdravookhranenniiai Istor Med ; 30(s1): 1061-1066, 2022 Dec 15.
Article in Russian | MEDLINE | ID: covidwho-2117183

ABSTRACT

An important goal of COVID-19 surveillance is to detect outbreaks using modern molecular epidemiology techniques based on methods to decode the full genome of the virus, since rapidly evolving RNA viruses, which include SARS-CoV-2, are constantly accumulating changes in their genomes. In addition to using these changes to identify the different virus lines spreading in the population, the availability of sequence information is very important. It will allow the identification of altered variants that may be more transmissible, cause more severe forms of disease, or be undetectable by existing diagnostic test systems. The global scientific community is particularly interested in changes in the spike protein (S-protein, Spike) because they are responsible for binding and penetration into the host cell, lead to false-negative results in diagnostic tests, and affect transmission rates, health outcomes, therapeutic interventions, and vaccine efficacy.Genomic surveillance uses next-generation sequencing (NGS) applications and makes data on the full genome of the virus available. These methods offer new means to detect variants that differ phenotypically or antigenically. This approach promotes earlier prediction as well as effective strategies to mitigate and contain outbreaks of SARS-CoV-2 and other new viruses long before they spread worldwide.Today, molecular typing of strains is playing an increasingly important role in this process, as it makes it possible to identify samples that share a common molecular «fingerprint¼.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , Genome, Viral , Phylogeny , Moscow/epidemiology , COVID-19/diagnosis , COVID-19/epidemiology , Genomics
17.
Nat Commun ; 13(1): 7003, 2022 Nov 16.
Article in English | MEDLINE | ID: covidwho-2116500

ABSTRACT

Genomic sequencing is essential to track the evolution and spread of SARS-CoV-2, optimize molecular tests, treatments, vaccines, and guide public health responses. To investigate the global SARS-CoV-2 genomic surveillance, we used sequences shared via GISAID to estimate the impact of sequencing intensity and turnaround times on variant detection in 189 countries. In the first two years of the pandemic, 78% of high-income countries sequenced >0.5% of their COVID-19 cases, while 42% of low- and middle-income countries reached that mark. Around 25% of the genomes from high income countries were submitted within 21 days, a pattern observed in 5% of the genomes from low- and middle-income countries. We found that sequencing around 0.5% of the cases, with a turnaround time <21 days, could provide a benchmark for SARS-CoV-2 genomic surveillance. Socioeconomic inequalities undermine the global pandemic preparedness, and efforts must be made to support low- and middle-income countries improve their local sequencing capacity.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , Genome, Viral/genetics , COVID-19/epidemiology , Pandemics , Genomics
18.
Sci Rep ; 12(1): 18968, 2022 Nov 08.
Article in English | MEDLINE | ID: covidwho-2106454

ABSTRACT

The Alpha (B.1.1.7) and Omicron (B.1.1.529, BA.1, BA.4 and BA.5) variants of concern (VOC) share several mutations in their spike gene, including mutations resulting in the deletion of two amino acids at position 69 and 70 (del 69-70) in the Spike protein. Del 69-70 causes failure to detect the S gene target on a widely used, commercial test, the TaqPath SARS-CoV-2 RT-PCR (Thermo Fisher). The S gene target failure (SGTF) signature has been used to preliminarily infer the presence of Alpha and Omicron VOC. We evaluated the accuracy of the SGTF signature in identifying these two variants through analysis of all positive SARS-CoV-2 samples tested on the TaqPath RT-PCR and sequenced by next generation sequencing between December 2020 to July 2022. 2324 samples were successfully sequenced including 914 SGTF positive samples. The sensitivity and specificity of the SGTF signature was 99.6% (95% CI 96.1-99.9%) and 98.6% (95% CI 99.2-99.8%) for the Alpha variant and 99.6% (95% CI 98.9-99.9%) and 99.8% (95% CI 99.4-99.9%) for the Omicron variant. At the peak of their corresponding wave, the positive predictive value of the SGTF was 98% for Alpha and 100% for Omicron. The accuracy of the SGTF signature was high, making this genomic signature a rapid and accurate proxy for identification of these variants in real-world laboratory settings.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , RNA, Viral/genetics , COVID-19/genetics , Genomics
19.
J Biol Chem ; 298(11): 102560, 2022 Nov.
Article in English | MEDLINE | ID: covidwho-2105268

ABSTRACT

The nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus 2 is responsible for compaction of the ∼30-kb RNA genome in the ∼90-nm virion. Previous studies suggest that each virion contains 35 to 40 viral ribonucleoprotein (vRNP) complexes, or ribonucleosomes, arrayed along the genome. There is, however, little mechanistic understanding of the vRNP complex. Here, we show that N protein, when combined in vitro with short fragments of the viral genome, forms 15-nm particles similar to the vRNP structures observed within virions. These vRNPs depend on regions of N protein that promote protein-RNA and protein-protein interactions. Phosphorylation of N protein in its disordered serine/arginine region weakens these interactions to generate less compact vRNPs. We propose that unmodified N protein binds structurally diverse regions in genomic RNA to form compact vRNPs within the nucleocapsid, while phosphorylation alters vRNP structure to support other N protein functions in viral transcription.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , Phosphorylation , RNA, Viral/metabolism , COVID-19/genetics , Nucleocapsid Proteins/metabolism , Ribonucleoproteins/metabolism , Genomics
20.
Viruses ; 14(11)2022 Nov 02.
Article in English | MEDLINE | ID: covidwho-2099857

ABSTRACT

To explore a genomic pool of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the pandemic, the Ministry of Health of the Slovak Republic formed a genomics surveillance workgroup, and the Public Health Authority of the Slovak Republic launched a systematic national epidemiological surveillance using whole-genome sequencing (WGS). Six out of seven genomic centers implementing Illumina sequencing technology were involved in the national SARS-CoV-2 virus sequencing program. Here we analyze a total of 33,024 SARS-CoV-2 isolates collected from the Slovak population from 1 March 2021, to 31 March 2022, that were sequenced and analyzed in a consistent manner. Overall, 28,005 out of 30,793 successfully sequenced samples met the criteria to be deposited in the global GISAID database. During this period, we identified four variants of concern (VOC)-Alpha (B.1.1.7), Beta (B.1.351), Delta (B.1.617.2) and Omicron (B.1.1.529). In detail, we observed 165 lineages in our dataset, with dominating Alpha, Delta and Omicron in three major consecutive incidence waves. This study aims to describe the results of a routine but high-level SARS-CoV-2 genomic surveillance program. Our study of SARS-CoV-2 genomes in collaboration with the Public Health Authority of the Slovak Republic also helped to inform the public about the epidemiological situation during the pandemic.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , Slovakia/epidemiology , COVID-19/epidemiology , Genome, Viral , High-Throughput Nucleotide Sequencing , Genomics
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