Multi-drug resistant Pseudomonas aeruginosa: a 2019–2020 single center retrospective case control study

Abstract

This was a retrospective case-control study of patients with P.aeruginosa isolates recovered from January 2019 to December 2020. MDR P.aeruginosa was defined as non-susceptibility to at least one agent in three or more anti-pseudomonal antimicrobial categories. In total, 258 unique isolates were identified. Prolonged hospitalization (P<0.001), prior antibiotic use (P<0.001), and respiratory sources (P<0.001) were strongly associated with the presence of MDR P.aeruginosa. From 2019 to 2020, there was a decrease in the total number of P.aeruginosa isolates but a significant increase in the proportion of MDR P.aeruginosa isolates (P=0.015). Over a period that coincided with the COVID-19 pandemic, there was an increased proportion of MDR P.aeruginosa isolates from hospitalized patients. Improved identification of patients at risk for MDR P.aeruginosa could facilitate appropriate empiric antibiotic decisions like dual anti-pseudomonal therapy. The features of the COVID-19 outbreak that had a severe impact on patient care and that may have affected drug resistance in other respiratory pathogens should be explored.