Prevalence of bacterial pathogens and potential role in COVID-19 severity in patients admitted to intensive care units in Brazil

Secondary bacterial and fungal infections are associated with respiratory viral infections and invasive mechanical ventilation. In Coronavirus disease 2019 (COVID-19), lung injury by SARS-CoV-2 and impaired immune response can provide a favorable environment for microorganism growth and colonization in hospitalized individuals. Recent studies suggest that secondary bacterial pneumonia is a risk factor associated with COVID-19. In Brazil, knowledge about microbiota present in COVID-19 patients is incipient. This work describes the microbiota of 21 COVID-19 patients admitted to intensive care units from two Brazilian centers. We identified respiratory, nosocomial and bacterial pathogens as prevalent microorganisms. Other bacterial opportunistic and commensal species are also represented. Virulence factors of these pathogenic species, metabolic pathways used to evade and modulate immunological processes and the interconnection between bacterial presence and virulence in COVID-19 progression are discussed. Article Summary Line We identified respiratory, nosocomial and bacterial pathogens as prevalent microorganisms in 21 Brazilian COVID-19 patients admitted to Intensive Care Units. Pathogen virulence factors and immune response evasion metabolic pathways are correlated to COVID-19 severity.