Microbiota of upper respiratory tract in COVID-19

Abstract

The COVID-19 pandemic has provided an additional impetus for studying the respiratory microbiome. Dysbiotic changes resulting from the interaction of the SARS-CoV-2 virus with respiratory tract cells can increase the body’s susceptibility to secondary infections or exacerbate the severity of the underlying disease. Several studies indicate a protective effect of individual representatives of the normal microbiota in interaction with viruses that cause acute respiratory infections. Despite the contradictory results caused by differences in research methods, different techniques for selecting biomaterial, differences in the severity of patients examined groups, the presence of concomitant diseases and other factors, the obtained data allows to consider the respiratory microbiome as one of the main links in the pathogenesis of COVID-19 infection. The aim of this work was to review studies on the composition of the upper respiratory tract microbiota and the significance of secondary infections in the pathogenesis of COVID-19. The article provides detailed information on recent scientific data on the composition of the upper respiratory tract microbiota in SARS-CoV-2 infected individuals and possible mechanisms of protective action of microorganisms against the new coronavirus. The work presents a review of studies devoted to secondary bacterial and fungal co-infections caused by conditionally pathogenic representatives of the respiratory tract microbiota and superinfections by hospital pathogens: bacteria (mainly from the group of ESCAPE pathogens with multiple drug resistance) and fungi – micromycetes. The question of further perspectives for developing new diagnostic and therapeutic approaches to correct dysbiotic disorders of the respiratory microbiome associated with the damaging effect of the SARS-CoV-2 coronavirus is discussed.