ABSTRACT
INTRODUCTION: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), mainly transmitted by droplets and close contact, has caused a pandemic worldwide as of March 2020. According to the current case reports and cohort studies, the symptoms of pregnant women infected with SARS-CoV-2 were similar to normal adults and may cause a series of adverse consequences of pregnancy (placental abruption, fetal distress, epilepsy during pregnancy, etc.). However, whether SARS-CoV-2 can be transmitted to the fetus through the placental barrier is still a focus of debate. METHODS: In this study, in order to find out whether SARS-CoV-2 can infect fetus through the placental barrier, we performed qualitative detection of virus structural protein (spike protein and nucleoprotein) and targeted receptor protein Angiotensin Converting Enzyme 2 (ACE2), Basigin (CD147) and molecular chaperone GRP78 expression on the placental tissue of seven pregnant women diagnosed with COVID-19 through immunohistochemistry. Amniotic fluid, neonatal throat, anal swab and breastmilk samples were collected immediately in the operating room or delivery room for verification after delivery, which were all tested for SARS-CoV-2 by reverse transcriptionpolymerase chain reaction (RT-PCR). RESULTS/DISCUSSION: The result showed that CD147 was expressed on the basal side of the chorionic trophoblast cell membrane and ACE2 was expressed on the maternal side, while GRP78 was strongly expressed in the cell membrane and cytoplasm. The RT-PCR results of Amniotic fluid, neonatal throat, anal swab and breastmilk samples were all negative. On the basis of these findings, we speculated that it may be due to the placental barrier between mother and baby, for example, villous matrix and interstitial blood vessels have low expression of virus-related receptors (ACE2, CD147, GRP78), the probability of vertical transmission of SARS-CoV-2 through the placenta is low.
Subject(s)
COVID-19/transmission , Infectious Disease Transmission, Vertical , Placenta/virology , Pregnancy Complications, Infectious/virology , SARS-CoV-2 , Adult , Amniotic Fluid/virology , Angiotensin-Converting Enzyme 2/analysis , Basigin/analysis , COVID-19 Testing , China , Endoplasmic Reticulum Chaperone BiP , Female , Fetal Diseases/virology , Heat-Shock Proteins/analysis , Humans , Infant, Newborn , Nucleoproteins/analysis , Placenta/chemistry , Pregnancy , Reverse Transcriptase Polymerase Chain Reaction , Spike Glycoprotein, Coronavirus/analysisABSTRACT
Mass spectrometry (MS) can deliver valuable diagnostic data that complement genomic information and allow us to increase our current knowledge of the COVID-19 disease caused by the SARS-CoV-2 virus. We developed a simple, MS-based method to specifically detect SARS-CoV-2 proteins from gargle solution samples of COVID-19 patients. The protocol consists of an acetone precipitation and tryptic digestion of proteins contained within the gargle solution, followed by a targeted MS analysis. Our methodology identifies unique peptides originating from SARS-CoV-2 nucleoprotein. Building on these promising initial results, faster MS protocols can now be developed as routine diagnostic tools for COVID-19 patients. Data are available via ProteomeXchange with identifier PXD019423.
Subject(s)
Betacoronavirus/chemistry , Coronavirus Infections/diagnosis , Mass Spectrometry/methods , Mouth/virology , Pneumonia, Viral/diagnosis , COVID-19 , COVID-19 Testing , Chromatography, High Pressure Liquid , Clinical Laboratory Techniques , Coronavirus Infections/virology , Humans , Nucleoproteins/analysis , Nucleoproteins/chemistry , Pandemics , Peptide Fragments/analysis , Peptide Fragments/chemistry , Pneumonia, Viral/virology , SARS-CoV-2 , Viral Proteins/analysis , Viral Proteins/chemistryABSTRACT
At the time of writing, FIND has listed four CE-marked SARSCoV-2 antigen tests. We evaluated the recently CE-approved rapid POCT SD-Biosensor for SARS-CoV-2 nucleoprotein detection in nasopharyngeal secretions from 330 patients admitted to the Emergency Room for a suspect of COVID-19 and travelers returning home from high risk countries. Sensitivity, specificity, accuracy, negative and predictive values were consistent with the use of the test to mass-screening for SARS-CoV-2 surveillance.
Subject(s)
Antigens, Viral/analysis , Biosensing Techniques/methods , COVID-19 Testing/methods , COVID-19/diagnosis , SARS-CoV-2 , Humans , Immunologic Tests , Mass Screening , Nasopharynx/virology , Nucleoproteins/analysis , Real-Time Polymerase Chain Reaction , Sensitivity and Specificity , Viral Proteins/analysisABSTRACT
We found that a single nucleotide polymorphism (SNP) in the nucleoprotein gene of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from a patient interfered with detection in a widely used commercial assay. Some 0.2% of the isolates in the EpiCoV database contain this SNP. Although SARS-CoV-2 was still detected by the other probe in the assay, this underlines the necessity of targeting two independent essential regions of a pathogen for reliable detection.