SARS-CoV-2 infection predisposes patients to coinfection with .

Unlabelled: Severe COVID-19 has been associated with coinfections with bacterial and fungal pathogens. Notably, patients with COVID-19 who develop bacteremia exhibit higher rates of mortality than those infected with either pathogen alone. To understand this clinical scenario, we collected and examined blood and respiratory isolates from a hospital in New York City during the early phase of the pandemic from both SARS-CoV-2+ and SARS-CoV-2- patients. Whole genome sequencing of these isolates revealed broad phylogenetic diversity in both patient groups, suggesting that SARS-CoV-2 coinfection was not associated with a particular lineage. Phenotypic characterization of the contemporary collection of isolates from SARS-CoV-2+ and SARS-CoV-2- patients revealed no notable differences in several virulence traits examined. However, we noted a trend toward overrepresentation of bloodstream strains with low cytotoxicity in the SARS-CoV-2+ group. We observed that patients coinfected with SARS-CoV-2 and were more likely to die during the acute phase of infection when the coinfecting strain exhibited high or low cytotoxicity. To further investigate the relationship between SARS-CoV-2 and infections, we developed a murine coinfection model. These studies revealed that infection with SARS-CoV-2 renders mice susceptible to subsequent superinfection with low cytotoxicity . Thus, SARS-CoV-2 infection sensitizes the host to coinfections, including isolates with low intrinsic virulence.

Importance: The COVID-19 pandemic has had an enormous impact on healthcare across the globe. Patients who were severely infected with SARS-CoV-2, the virus causing COVID-19, sometimes became infected with other pathogens, which is termed coinfection. If the coinfecting pathogen is the bacterium , there is an increased risk of patient death. We collected strains that coinfected patients with SARS-CoV-2 to study the disease outcome caused by the interaction of these two important pathogens. We found that both in patients and in mice, coinfection with an strain lacking toxicity resulted in more severe disease during the early phase of infection, compared with infection with either pathogen alone. Thus, SARS-CoV-2 infection can directly increase the severity of infection.