Combination of two rare mutations in the SARS-CoV-2 M gene in patients with severe and prolonged COVID-19

Abstract

Background

The SARS-CoV-2 virus significantly changed our knowledge about coronaviruses. The interplay between SARS-CoV-2 and the human host, the infection ranges from asymptomatic to lethal, and differences in the degree of disease severity are important examples.

Methods

In this retrospective study, 24 nasopharyngeal swabs from 21 out of 457 patients with SARS-CoV-2 infection were analysed by whole-genome sequencing. The principal selection criteria were the duration of infection and disease severity.

Results

Two co-occurring rare mutations in the SARS-CoV-2 M gene were detected in six samples. Three of these samples were collected from an immunocompromised patient with fatal outcome, two from an immunocompetent patient, and one from a patient with severe disease and fatal outcome, all with a prolonged course of infection.

Conclusions

Although this interesting finding was demonstrated in a small number of patients, the results increase the knowledge regarding the significance of mutations in the M gene of SARS-CoV-2 in the context of persistent infection and viral escape mechanisms.

Keywords:

• COVID-19 
• M gene
• mutation
• SARS-CoV-2
• prolonged infection

Acknowledgements

The authors thank the patients for providing samples and the hospital staff for their assistance with data collection. The authors would like to thank Mr. Lubomir Balabanski, Mrs. Maya Atanasoska and Mrs. Slavyana Yaneva-Staykova for their support with SARS-CoV-2 whole-genome sequencing and primary data analysis. Lastly, Martin Pasev for proofreading the manuscript.

Ethical approval

This study was approved by the institutional ethic review board of Lozenetz University Hospital, Decision No. 354/21.02.2023.

Disclosure statement

The authors report there are no competing interests to declare.

Additional information

Funding

This work was supported by a research grant from The Sofia University “Sv. Kliment Ohridski”, Research Council, Contract Number 80-10-185/2021.