Staphylococcus aureus nasal carriage is a potential source of secondary infections in COVID-19 patients, yet it remains unclear whether SARS-CoV-2 infection favors colonization by more virulent or resistant strains. We analyzed 31 nasal S. aureus isolates from hospitalized COVID-19 patients to assess antimicrobial resistance, virulence gene content, and genetic diversity. Only two isolates (6.4%) were methicillin resistant, and most strains showed limited resistance beyond the MLSB phenotype. Adhesin genes were highly prevalent, whereas toxin genes were detected in only 16.1% of isolates. Spa typing revealed high genetic diversity with no dominant clone. Overall, S. aureus isolates from COVID-19 patients did not differ substantially from previously described carriage strains, suggesting no selective enrichment of highly virulent or resistant lineages during SARS-CoV-2 infection.
Piechowicz et al. (Tue,) studied this question.