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1.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-307867

ABSTRACT

Coronavirus 2 (SARS-CoV-2) infection and the resulting COVID-19 illness vary from asymptomatic disease, mild upper respiratory tract infection, pneumonia 1 , to a life-threatening multi-organ failure with case fatality rates ranging from 0.27–13.4% 2,3 . Despite increasing knowledge of the clinical and immunological features underlying COVID-19 1,4−6 , biological variables explaining the course of infection and its severity remain elusive. At the entry site of SARS-CoV2, the oropharyngeal microbiome represents a hub integrating viral and immune signals at the start of the infection 7–10 . To evaluate the role of the oropharyngeal microbiome in COVID-19, we performed a multi-center, cross-sectional clinical study analyzing the oropharyngeal microbial metagenomes in healthy adults, patients with non-SARS-CoV-2 infections, or with mild, moderate and severe COVID-19 encompassing a total of 345 participants. Significantly reduced microbiome diversity and high dysbiosis were observed in hospitalized patients with severe COVID-19, which was further associated with a loss of microbial genes and metabolic pathways. In this cohort, diversity measures were also associated with need for intensive care treatments as major clinical parameters in COVID-19. We further applied random forest machine learning to unravel microbial features for segregating clinical outcomes in hospitalized cases, and observed oropharyngeal microbiome abundances of Haemophilus or Streptococcu s species as most important features. These findings provide insights into the role of the oropharyngeal microbiome in SARS-CoV-2 infection, and may suggest new biomarkers for COVID-19 severity.

2.
Clin Infect Dis ; 2021 Oct 25.
Article in English | MEDLINE | ID: covidwho-1483417

ABSTRACT

BACKGROUND: At the entry site of respiratory virus infections, the oropharyngeal microbiome has been proposed as a major hub integrating viral and host immune signals. Early studies suggested that infections with Coronavirus 2 (SARS-CoV-2) are associated with changes of the upper and lower airway microbiome, and that specific microbial signatures may predict COVID-19 illness. However, the results are not conclusive, as critical illness can drastically alter a patient's microbiome through multiple confounders. METHODS: To study oropharyngeal microbiome profiles in SARS-CoV-2 infection, clinical confounders, and prediction models in COVID-19, we performed a multi-center, cross-sectional clinical study analyzing oropharyngeal microbial metagenomes in healthy adults, patients with non-SARS-CoV-2 infections, or with mild, moderate and severe COVID-19 (n=322 participants). RESULTS: In contrast to mild infections, patients admitted to a hospital with moderate or severe COVID-19 showed dysbiotic microbial configurations, which were significantly pronounced in patients treated with broad-spectrum antibiotics, receiving invasive mechanical ventilation, or when sampling was performed during prolonged hospitalization. In contrast, specimens collected early after admission allowed us to segregate microbiome features predictive of hospital COVID-19 mortality utilizing machine learning models. Taxonomic signatures were found to perform better than models utilizing clinical variables with Neisseria and Haemophilus species abundances as most important features. CONCLUSION: In addition to the infection per se, several factors shape the oropharyngeal microbiome of severely affected COVID-19 patients and deserve consideration in the interpretation of the role of the microbiome in severe COVID-19. Nevertheless, we were able to extract microbial features that can help to predict clinical outcomes.

3.
Viruses ; 12(8)2020 08 07.
Article in English | MEDLINE | ID: covidwho-713633

ABSTRACT

Rapid large-scale testing is essential for controlling the ongoing pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The standard diagnostic pipeline for testing SARS-CoV-2 presence in patients with an ongoing infection is predominantly based on pharyngeal swabs, from which the viral RNA is extracted using commercial kits, followed by reverse transcription and quantitative PCR detection. As a result of the large demand for testing, commercial RNA extraction kits may be limited and, alternatively, non-commercial protocols are needed. Here, we provide a magnetic bead RNA extraction protocol that is predominantly based on in-house made reagents and is performed in 96-well plates supporting large-scale testing. Magnetic bead RNA extraction was benchmarked against the commercial QIAcube extraction platform. Comparable viral RNA detection sensitivity and specificity were obtained by fluorescent and colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) using a primer set targeting the N gene, as well as RT-qPCR using a primer set targeting the E gene, showing that the RNA extraction protocol presented here can be combined with a variety of detection methods at high throughput. Importantly, the presented diagnostic workflow can be quickly set up in a laboratory without access to an automated pipetting robot.


Subject(s)
Betacoronavirus/chemistry , Betacoronavirus/genetics , Clinical Laboratory Techniques/methods , Coronavirus Infections/virology , Pneumonia, Viral/virology , RNA, Viral/isolation & purification , Betacoronavirus/isolation & purification , COVID-19 , COVID-19 Testing , Coronavirus Infections/diagnosis , Humans , Magnetic Phenomena , Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods , Pandemics , Pneumonia, Viral/diagnosis , RNA, Viral/genetics , Real-Time Polymerase Chain Reaction/methods , Reverse Transcription , SARS-CoV-2 , Sensitivity and Specificity
4.
Sci Transl Med ; 12(556)2020 08 12.
Article in English | MEDLINE | ID: covidwho-688785

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic caused by the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) coronavirus is a major public health challenge. Rapid tests for detecting existing SARS-CoV-2 infections and assessing virus spread are critical. Approaches to detect viral RNA based on reverse transcription loop-mediated isothermal amplification (RT-LAMP) have potential as simple, scalable, and broadly applicable testing methods. Compared to RT quantitative polymerase chain reaction (RT-qPCR)-based methods, RT-LAMP assays require incubation at a constant temperature, thus eliminating the need for sophisticated instrumentation. Here, we tested a two-color RT-LAMP assay protocol for detecting SARS-CoV-2 viral RNA using a primer set specific for the N gene. We tested our RT-LAMP assay on surplus RNA samples isolated from 768 pharyngeal swab specimens collected from individuals being tested for COVID-19. We determined the sensitivity and specificity of the RT-LAMP assay for detecting SARS-CoV-2 viral RNA. Compared to an RT-qPCR assay using a sensitive primer set, we found that the RT-LAMP assay reliably detected SARS-CoV-2 RNA with an RT-qPCR cycle threshold (CT) number of up to 30, with a sensitivity of 97.5% and a specificity of 99.7%. We also developed a swab-to-RT-LAMP assay that did not require a prior RNA isolation step, which retained excellent specificity (99.5%) but showed lower sensitivity (86% for CT < 30) than the RT-LAMP assay. In addition, we developed a multiplexed sequencing protocol (LAMP-sequencing) as a diagnostic validation procedure to detect and record the outcome of RT-LAMP reactions.


Subject(s)
Betacoronavirus/genetics , Betacoronavirus/isolation & purification , Coronavirus Infections/diagnosis , Coronavirus Infections/virology , Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods , Pneumonia, Viral/diagnosis , Pneumonia, Viral/virology , COVID-19 , Colorimetry/methods , Colorimetry/statistics & numerical data , Coronavirus Infections/epidemiology , Coronavirus Nucleocapsid Proteins , Humans , Molecular Diagnostic Techniques/statistics & numerical data , Nucleic Acid Amplification Techniques/statistics & numerical data , Nucleocapsid Proteins/genetics , Pandemics , Phosphoproteins , Pneumonia, Viral/epidemiology , RNA, Viral/genetics , RNA, Viral/isolation & purification , RNA-Seq , SARS-CoV-2 , Sensitivity and Specificity
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