Clinical aspects and characterization of Pseudomonas aeruginosa isolated from patients infected with SARS-CoV-2

Aims: This study aimed to identify and characterize Pseudomonas aeruginosa isolates from patients infected and uninfected with SARS-CoV-2, focusing on their phenotypic characteristics and antimicrobial resistance profiles.

Main methods: A total of 100 P. aeruginosa isolates were obtained from patients admitted to a hospital in Presidente Prudente, SP, in 2021. The isolates were assessed for antimicrobial resistance, pyocyanin, lipase and phospholipase C production, biofilm formation, and the presence of virulence factor genes, including those associated with metallo-β-lactamase (MBL) production.

Key findings: Among the isolates, 58 were from patients infected with SARS-CoV-2 and 42 from non-infected patients. P. aeruginosa was predominantly isolated from tracheal secretion samples in infected patients, while urine samples were more common in non-infected patients. Notably, patients with SARS-CoV-2 exhibited a higher rate of resistance to aztreonam and used a wider range of antibiotics. Isolates from infected patients demonstrated higher phospholipase C production and a greater number classified as strong biofilm formers. Virulence factor genes were present in at least 70% of the isolates, while only three isolates showed genes for MBL production.

Significance: The findings of this study indicate that the COVID-19 pandemic creates a favorable environment for the increase of secondary infections by P. aeruginosa. Understanding the characteristics and resistance profiles of these isolates is crucial for improving treatment strategies and patient outcomes.