Abstract
SARS-CoV-2 is the causative of the COVID-19 disease, which has spread pandemically around the globe within a few months. It is therefore necessary to collect fundamental information about the disease, its epidemiology and treatment, as well as about the virus itself. While the virus has been identified rapidly, detailed ultrastructural analysis of virus cell biology and architecture is still in its infancy. We therefore studied the virus morphology and morphometry of SARS-CoV-2 in comparison to SARS-CoV as it appears in Vero cell cultures by using conventional thin section electron microscopy and electron tomography. Both virus isolates, SARS-CoV Frankfurt 1 and SARS-CoV-2 Italy-INMI1, were virtually identical at the ultrastructural level and revealed a very similar particle size distribution with a median of about 100 nm without spikes. Maximal spike length of both viruses was 23 nm. The number of spikes per virus particle was about 30% higher in the SARS-CoV than in the SARS-CoV-2 isolate. This result complements a previous qualitative finding, which was related to a lower productivity of SARS-CoV-2 in cell culture in comparison to SARS-CoV.
Highlights
The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a Betacoronavirus which entered the human population most probably at the end of 2019 and is spreading pandemically around the world[1]
In conventional thin section electron microscopy (EM) of virus producing cell cultures and demonstrate that the investigated SARSCoV and SARS-CoV-2 isolates are very similar in their ultrastructure apart from a small difference in their spike number
Size distributions of virus particle profiles in conventional ultrathin (65 nm) sections were similar for both viruses (Fig. 3A,B)
Summary
The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a Betacoronavirus which entered the human population most probably at the end of 2019 and is spreading pandemically around the world[1]. SARS-CoV-2 is genetically similar to SARS-CoV (79% sequence identity4) which appeared in the human population in 2003. Both viruses use the same receptor (i.e. the angiotensin-converting enzyme 2, ACE2) for host cell entry[5]. To provide reference data for this purpose, we carried out a study on the morphometry of virus particles of SARS-CoV-2 in comparison to virus particles of SARS-CoV by using transmission EM of the virus in thin sections of plastic embedded infected cell cultures. In conventional thin section EM of virus producing cell cultures and demonstrate that the investigated SARSCoV and SARS-CoV-2 isolates are very similar in their ultrastructure apart from a small difference in their spike number
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
