LitCovid-sentences  

PMC:7036342 / 811-7680 JSONTXT 14 Projects

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Id Subject Object Predicate Lexical cue
T8 0-163 Sentence denotes Coronaviruses (CoVs), within the order Nidovirales, are enveloped, single-strand, positive-sense RNA viruses with a large genome of approximately 30 kbp in length.
T9 164-382 Sentence denotes CoV was cultured for the first time in human embryonic tracheal organ cultures by Tyrrell and Bynoe in 1965,1 and it was named as ‘corona’ due to crown-like appearance of the surface projections on electron microscopy.
T10 383-562 Sentence denotes All CoVs develop only in the cytoplasm of infected cells, bud into cytoplasmic vesicles, and then extrude in virus particles of 70–80 nm in diameter by exocytic secretory pathway.
T11 563-801 Sentence denotes Among four genera of CoVs, beta-CoV includes five subgenus—embevovirus, sarbecovirus including severe acute respiratory syndrome (SARS)-CoV, merbecovirus including Middle East respiratory syndrome (MERS)-CoV, nobecovirus, and hibecovirus.
T12 802-899 Sentence denotes Because CoVs can infect a variety of animals, SARS-CoV and MERS-CoV crossed the species barriers.
T13 900-1265 Sentence denotes Since December 2019, 2019 novel CoV (SARS-CoV-2) has been making a large outbreak involving 49,053 laboratory-confirmed patients and 1,383 mortality in 25 countries including Korea until February 14, 2020.2 In the outbreak situation, isolation of causative virus is indispensable for developing and evaluating diagnostic tools, therapeutics, and vaccine candidates.
T14 1266-1649 Sentence denotes SARS-CoV-2 was first isolated using human airway epithelial cells and it was classified into the subgenus sarbecovirus of beta-CoVs by phylogenetic analyses of the gene sequences.3 Both the SARS-CoV and the MERS-CoV were initially isolated and grew readily in Vero cells.45 Here, we report the isolation of SARS-CoV-2 using Vero cells from a patient entering Korea from Wuhan, China.
T15 1650-1902 Sentence denotes The patient with the first laboratory-confirmed SARS-CoV-2 infection in Korea is published previously.6 Briefly, a 35-year-old woman developed fever, chill, and myalgia on January 18, 2020, and arrived at the Incheon airport from Wuhan on the next day.
T16 1903-2015 Sentence denotes After laboratory-confirmed diagnosis of SARS-CoV-2 infection, she developed nasal congestion, cough, and sputum.
T17 2016-2144 Sentence denotes Oxygen supplementation was started on day 4 of her illness, and her oxygen requirement increased to 6 L/min on day 7 of illness.
T18 2145-2257 Sentence denotes Fever persisted for ten days and her maximum body temperature during her illness was 38.9°C on day 7 of illness.
T19 2258-2435 Sentence denotes The patient's oropharyngeal samples were obtained by using UTM™ kit containing 1 mL of viral transport media (Copan Diagnostics Inc., Murrieta, CA, USA) on day 7 of her illness.
T20 2436-2574 Sentence denotes We inoculated monolayers of Vero cells (ATCC ® CCL-81™) with the samples and cultured the cells at 37°C in a 5% carbon dioxide atmosphere.
T21 2575-3196 Sentence denotes Until 5 days after inoculation, cytopathic effects were not distinct, which is compatible with the previous findings that no specific cytopathic effects were observed in the Vero E6 cells until 6 days after inoculation in the report about first isolation of SARS-CoV-2.3 Five days after inoculation, we did blind passage of culture supernatant into T-25 culture flask (ThermoFisher Scientific Inc., Waltham, MA, USA) with monolayers of Vero cells, and cytopathic effects consisting of rounding and detachment of cells were observed in the whole area of the T-25 flask 3 days after the first blind passage (Fig. 1A and B).
T22 3197-3403 Sentence denotes In order to observe virus particles, Vero cell monolayer showing the cytopathic effects was fixed as previously described.7 It was cut on ultramicrotome (RMC MT-XL; RMC Boeckeler, Tucson, AZ, USA) at 65 nm.
T23 3404-3601 Sentence denotes Ultrathin sections were stained with saturated 4% uranyl acetate and 1% lead citrate before examination with a transmission electron microscope (JEM-1400; JEOL USA Inc., Peabody, MA, USA) at 80 kV.
T24 3602-3796 Sentence denotes Spherical particles with crown-like spikes ranging 66 to 81 nm in diameter were observed within the cytoplasmic vesicles and in the extracellular space adjacent to cell membrane (Fig. 1C and D).
T25 3797-3945 Sentence denotes For whole genome sequencing of the virus isolate (BetaCoV/Korea/SNU01/2020), culture supernatant of Vero cells infected was used for RNA extraction.
T26 3946-4073 Sentence denotes RNA was extracted by using QIAamp viral RNA mini kit (QIAGEN, Valencia, CA, USA), according to the manufacturer's instructions.
T27 4074-4150 Sentence denotes RNA libraries were prepared using TruSeq Stranded Total RNA Kit (catalog No.
T28 4151-4230 Sentence denotes 20020596; Illumina, San Diego, CA, USA) according to the manufacturer protocol.
T29 4231-4512 Sentence denotes Sequencing was performed on an Illumina Nextseq 500 platform, produced on average a total of 150 million reads, 150 bp per sample, as per the manufacturer's instructions in Macrogen Inc. (Seoul, Korea).8910 FASTQ was used to trim the adapter and remove low quality bases and reads.
T30 4513-4899 Sentence denotes Qualified reads were mapped to NC_045512, a SARS-CoV-2 genome reference using Burrows-Wheeler Aligner (v0.7.12-r1039), and a bam file was produced.11 In this bam file, the variation was confirmed by comparing with genome using SAMtools (v1.3.1).12 For genome-base phylogeny analysis, 37 strains including BetaCoV/Korea/KCDC03/2020 were used in combination with BetaCoV/Korea/SNU01/2020.
T31 4900-5024 Sentence denotes The sequences used for analysis were downloaded from NCBI (http://www.ncbi.nlm.nih.gov/) and GISAID (http://www.gisaid.org).
T32 5025-5358 Sentence denotes The 37 strain genomes were multiple-sequence aligned using MAFFT (v7.450), a sequence alignment tool, and were used to generate phylogenetic tree.13 Phylogenetic analysis of the aligned sequence was performed with 1,000 bootstrap replicates using MEGAX and a general time-reversible model used as the nucleotide substitution model.14
T33 5359-5436 Sentence denotes Next-generation sequencing of BetaCoV/Korea/SNU01/2020 (GenBank accession no.
T34 5437-5541 Sentence denotes MT039890) revealed 9 mutations compared to the NC_045512 reference genome isolated from Wuhan (Table 1).
T35 5542-5650 Sentence denotes Most of the mutations in our isolate consisted of 70% alternative genes and 30% reference genes (NC_045512).
T36 5651-5759 Sentence denotes Five variants were found in ORF1ab, one variant in S gene, two variants in ORF3a, and one variant in E gene.
T37 5760-5822 Sentence denotes Of the nine mutations, six also showed changes in amino acids.
T38 5823-6014 Sentence denotes When comparing our isolate with the one isolated from the Korea Centers for Disease Control and Prevention (BetaCoV/Korea/KCDC03/2020), 12 variants including the above 9 mutations were found.
T39 6015-6200 Sentence denotes These mutations may occur by cell culture-adaptation in that our culture isolate was obtained after first blind passage, or by micro-evolution of SARS-CoV-2 before acquisition in Wuhan.
T40 6201-6314 Sentence denotes Because those genome sequences are quite homologous each other, it is difficult to validate these two hypothesis.
T41 6315-6432 Sentence denotes The phylogenetic tree was analyzed using 37 genome information including CoVs isolated from Korea and Wuhan (Fig. 2).
T42 6433-6616 Sentence denotes As a result, it was confirmed that our isolate is a beta-CoV belonging to the subgenus sarbecovirus, and that it closely clustered with other SARS-CoV-2 isolated from Korea and Wuhan.
T43 6617-6742 Sentence denotes In summary, we isolated SARS-CoV-2 using Vero cells from the first laboratory-confirmed SARS-CoV-2-infected patient in Korea.
T44 6743-6869 Sentence denotes Phylogenetic analyses of the whole genome sequences showed that it clustered with other SARS-CoV-2 reported from Wuhan, China.