ABSTRACT
To comparatively analyze the detection effect of viral nucleic acid in throat swab and sputum sample of 2019-nCoV cases. GAPDH housekeeping genes, viral ORF 1ab genes, N genes, and S genes were tested and compared by real-time RT-PCR in throat swabs and sputum specimens from 4 confirmed cases of 2019-nCoV. In the throat swabs and sputum samples of 4 cases, the human cell housekeeping gene GAPDH showed obvious and typical amplification signal curves. In the detection of viral ORF 1ab gene, N gene, and S gene, the amplification signal of sputum samples was stronger than that of throat swab, and the CT value of amplification curve was lower than that of throat swab, especially in case 1 and case 4, and the throat swab of case 4 showed negative results using commercial real-time RT-PCR kits, while the sputum specimens showed clear positive results. Therefore, in the viral nucleic acid testing of 2019-nCoV laboratory detection, the virus content in sputum specimens was higher than that in throat swab specimens, and the detection effect was better than that in throat swab specimens.
ABSTRACT
To investigate the status of viral infection in the feces of confirmed COVID-19, cases fecal samples or anal swabs from 36 confirmed cases were collected, 2019-nCoV was detected by real-time fluorescence RT-PCR, and the infection rates of the cases were compared by statistical analysis software SPSS 19.0. Among the 36 samples, 20 (55.56%) were positive for 2019-nCoV. The positive rate of critical cases (2/3) and severe cases(6/9) were both 66.67%, the positive rate of common pneumonia was 62.50% (10/16), and the positive rate of mild pneumonia was 25.00% (2/8). The 36 confirmed COVID-19 cases included 22 males and 14 females, with a detection rate of 54.55% and 57.14%, respectively. The age distribution range of the cases was ranging between 17 and 86 years old, with an average age of 48.75 years. Among the 36 samples, 2 positive specimens in 5 anal swab specimens and 18 positive specimens in 31 fecal specimens were detected. There were no statistically significant differences in the positive detection rates among clinical types, genders, ages and specimen types, respectively. From these results, we deduced that fecal samples of confirmed COVID-19 cases contained 2019-nCoV, which can cause infection through potential fecal-oral transmission and be significant for clinical treatment and epidemiological study.
ABSTRACT
BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the recent global COVID-19 outbreak, which led to a public health emergency. Entry of SARS-CoV-2 into human cells is dependent on the SARS-CoV receptor, angiotensin converting enzyme 2 (ACE2) receptor, and cathepsin. Cathepsin degrades the spike protein (S protein), which results in the entry of viral nucleic acid into the human host cell. METHODS: We explored the susceptibility of the central nervous system (CNS) to SARS-CoV-2 infection using single-cell transcriptome analysis of glioblastoma. RESULTS: The results showed that ACE2 expression is relatively high in endothelial cells (ECs), bone marrow mesenchymal stem cells (BMSCs), and neural precursor cells (NPCs). Cathepsin B (Cat B) and cathepsin (Cat L) were also strongly expressed in various cell clusters within the glioblastoma microenvironment. Immunofluorescence staining of glioma and normal brain tissue chips further confirmed that ACE2 expression co-localized with CD31, CD73, and nestin, which confirmed the susceptibility to SARS-CoV-2 of nervous system cells, including ECs, BMSCs, and NPCs, from clinical specimens. CONCLUSIONS: These findings reveal the mechanism of SARS-CoV-2 neural invasion and suggest that special attention should be paid to SARS-CoV-2-infected patients with neural symptoms, especially those who suffered a glioma.
ABSTRACT
To explore genomic characteriation of 2019-nCoV, throat swab specimens from COVID-19 patients were inoculated on Vero-E6 cells. Six days post-inoculation, supernatants of cell cultures were collected, tested, and sequenced on the Ion Torrent S5 Next-Generation Sequencing system. Two strains viruses were isolated from 12 specimens (eight of them were positive in ORF1ab gene and N gene, one of them was positive in N gene and three of them were negative in ORF1ab gene and N gene), as confirmed by online BLAST search at NCBI website. Genetic similarity of more than 99.9% were observed, from genomic level to structure genes including E, M, N and S genes, between the 2 isolates and the 2019-nCoV reference strain Wuhan-Hu-1 that isolated from Wuhan, Hubei province. Therefore, these results indicated that 2019-nCoV isolates in Fujian province have not mutated significantly yet so far.