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Short report
SARS-CoV-2: Preliminary study of infected human nasopharyngeal tissue by high resolution microscopy.
Brian Mondeja
Center for Advanced Studies of Cuba
Corresponding Author
ORCiD: https://orcid.org/0000-0001-6196-3570
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Background
The novel coronavirus SARS-CoV-2 is the etiological agent of COVID-19. This virus has become one of the most dangerous in recent times with a very high rate of transmission. At present, several publications show the typical crown-shape of the novel coronavirus grown in cell cultures. However, an integral ultramicroscopy study done directly from clinical specimens has not been published.
Methods
Nasopharyngeal swabs were collected from two Cuban individuals, one asymptomatic and RT-PCR negative (negative control) and the other from a COVID-19 symptomatic and RT-PCR positive for SARS CoV-2. Samples were treated with an aldehyde solution and processed by Scanning Electron Microscopy (SEM), Confocal Microscopy (CM) and, Atomic Force Microscopy (AFM). Improvement and segmentation of coronavirus images were performed by a novel mathematical image enhancement algorithm.
Results
The images of the negative control sample showed the characteristic healthy microvilli morphology at the apical region of the nasal epithelial cells. As expected, they do not display virus-like structures. The images of the positive sample showed characteristic coronavirus-like particles and evident destruction of microvilli. In some regions, virions budding through the cell membrane were observed. Microvilli destruction could explain the anosmia reported by some patients. Virus-particles emerging from the cell-surface with a variable size ranging from 80 to 400 nm were observed by scanning electron microscopy (SEM). Viral antigen was identified in the apical cells zone by CM.
Conclusions
The integral microscopy study showed that SARS-CoV-2 has a similar image to SARS-CoV. The application of several high-resolution microscopy techniques to nasopharyngeal samples awaits future use.
Keywords
coronavirus, SARS-CoV-2, SEM, AFM, microscopy
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CURRENT STATUS: Under Revision
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On 18 Jan, 2021
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On 17 Jan, 2021
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On 17 Jan, 2021
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No comments provided
Editorial decision: Major revision
On 14 Dec, 2020
Reviewer #1 agreed
On 12 Dec, 2020
Review #1 received
Received 12 Dec, 2020
Reviewers invited
Invitations sent on 06 Dec, 2020
Editor assigned
On 29 Nov, 2020
Submission checks complete
On 29 Nov, 2020
Editor invited
On 29 Nov, 2020
Version (no preprint)
Posted 25 Nov, 2020
Review #3 received
Received 25 Nov, 2020
Review #2 received
Received 23 Nov, 2020
Reviewer #3 agreed
On 22 Nov, 2020
Review #1 received
Received 21 Nov, 2020
Reviewer #2 agreed
On 18 Nov, 2020
Editor assigned
On 17 Nov, 2020
Reviewers invited
Invitations sent on 17 Nov, 2020
Reviewer #1 agreed
On 17 Nov, 2020
Submission checks complete
On 17 Nov, 2020
Editor invited
On 17 Nov, 2020
This version was not preprinted
No comments provided
Editorial decision: Major revision
On 04 Aug, 2020
Review #1 received
Received 02 Aug, 2020
Reviewer #5 agreed
On 27 Jul, 2020
Review #4 received
Received 27 Jul, 2020
Review #2 received
Received 27 Jul, 2020
Reviewer #4 agreed
On 24 Jul, 2020
Reviewer #1 agreed
On 23 Jul, 2020
Reviewer #2 agreed
On 23 Jul, 2020
Reviewer #3 agreed
On 23 Jul, 2020
Reviewers invited
Invitations sent on 23 Jul, 2020
Editor invited
On 29 Jun, 2020
Editor assigned
On 29 Jun, 2020
Submission checks complete
On 23 Jun, 2020
First submitted
On 17 Jun, 2020
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Subject Areas
Virology
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This preprint is under consideration at Virology Journal. A preprint is a preliminary version of a manuscript that has not completed peer review at a journal. Research Square does not conduct peer review prior to posting preprints. The posting of a preprint on this server should not be interpreted as an endorsement of its validity or suitability for dissemination as established information or for guiding clinical practice.
Learn more about In Review
Short report
SARS-CoV-2: Preliminary study of infected human nasopharyngeal tissue by high resolution microscopy.
Brian Mondeja
Center for Advanced Studies of Cuba
Corresponding Author
ORCiD: https://orcid.org/0000-0001-6196-3570
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
Peer Review Timeline
CURRENT STATUS: Under Revision
Version 3
Posted 22 Jan, 2021
No community comments so far
Editorial decision: Major revision
On 18 Jan, 2021
Editor assigned
On 17 Jan, 2021
Submission checks complete
On 17 Jan, 2021
Editor invited
On 17 Jan, 2021
No comments provided
Editorial decision: Major revision
On 14 Dec, 2020
Reviewer #1 agreed
On 12 Dec, 2020
Review #1 received
Received 12 Dec, 2020
Reviewers invited
Invitations sent on 06 Dec, 2020
Editor assigned
On 29 Nov, 2020
Submission checks complete
On 29 Nov, 2020
Editor invited
On 29 Nov, 2020
Version (no preprint)
Posted 25 Nov, 2020
Review #3 received
Received 25 Nov, 2020
Review #2 received
Received 23 Nov, 2020
Reviewer #3 agreed
On 22 Nov, 2020
Review #1 received
Received 21 Nov, 2020
Reviewer #2 agreed
On 18 Nov, 2020
Editor assigned
On 17 Nov, 2020
Reviewers invited
Invitations sent on 17 Nov, 2020
Reviewer #1 agreed
On 17 Nov, 2020
Submission checks complete
On 17 Nov, 2020
Editor invited
On 17 Nov, 2020
This version was not preprinted
No comments provided
Editorial decision: Major revision
On 04 Aug, 2020
Review #1 received
Received 02 Aug, 2020
Reviewer #5 agreed
On 27 Jul, 2020
Review #4 received
Received 27 Jul, 2020
Review #2 received
Received 27 Jul, 2020
Reviewer #4 agreed
On 24 Jul, 2020
Reviewer #1 agreed
On 23 Jul, 2020
Reviewer #2 agreed
On 23 Jul, 2020
Reviewer #3 agreed
On 23 Jul, 2020
Reviewers invited
Invitations sent on 23 Jul, 2020
Editor invited
On 29 Jun, 2020
Editor assigned
On 29 Jun, 2020
Submission checks complete
On 23 Jun, 2020
First submitted
On 17 Jun, 2020
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
Subject Areas
Virology
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Background
The novel coronavirus SARS-CoV-2 is the etiological agent of COVID-19. This virus has become one of the most dangerous in recent times with a very high rate of transmission. At present, several publications show the typical crown-shape of the novel coronavirus grown in cell cultures. However, an integral ultramicroscopy study done directly from clinical specimens has not been published.
Methods
Nasopharyngeal swabs were collected from two Cuban individuals, one asymptomatic and RT-PCR negative (negative control) and the other from a COVID-19 symptomatic and RT-PCR positive for SARS CoV-2. Samples were treated with an aldehyde solution and processed by Scanning Electron Microscopy (SEM), Confocal Microscopy (CM) and, Atomic Force Microscopy (AFM). Improvement and segmentation of coronavirus images were performed by a novel mathematical image enhancement algorithm.
Results
The images of the negative control sample showed the characteristic healthy microvilli morphology at the apical region of the nasal epithelial cells. As expected, they do not display virus-like structures. The images of the positive sample showed characteristic coronavirus-like particles and evident destruction of microvilli. In some regions, virions budding through the cell membrane were observed. Microvilli destruction could explain the anosmia reported by some patients. Virus-particles emerging from the cell-surface with a variable size ranging from 80 to 400 nm were observed by scanning electron microscopy (SEM). Viral antigen was identified in the apical cells zone by CM.
Conclusions
The integral microscopy study showed that SARS-CoV-2 has a similar image to SARS-CoV. The application of several high-resolution microscopy techniques to nasopharyngeal samples awaits future use.
Figure 1
Figure 2
Figure 3
Figure 4