Comparison of antimicrobial resistance patterns of bloodstream Pseudomonas aeruginosa isolates from two tertiary university hospitals in Türkiye and Hungary.

BACKGROUND: Pseudomonas aeruginosa is a major cause of healthcare-associated bloodstream infections, and its resistance patterns can vary by hospital setting, care unit, and time. This study compared resistance patterns of P. aeruginosa isolates recovered from blood cultures at two tertiary university hospitals in Türkiye and Hungary. METHODS: This retrospective, multicenter and cross-sectional surveillance study included the first eligible bloodstream P. aeruginosa isolates obtained from patients admitted to intensive care units (ICUs) and non-ICU wards between 2020 and 2023. Class-based resistance patterns to carbapenems, cephalosporins, and fluoroquinolones, as well as multidrug resistance (MDR), were evaluated using predefined criteria. Annual trends and center-by-year interactions were analyzed using log-binomial regression, while independent associations and exploratory period differences were assessed using logistic regression. RESULTS: A total of 703 patients were included (Turkish center = 180, Hungarian center = 523). Multivariate analyses identified independent associations of ward type with four resistance outcomes, center with cephalosporin resistance; year with fluoroquinolone resistance and MDR; and gender with fluoroquinolone resistance. Cephalosporin, fluoroquinolone, and MDR resistance declined significantly over time, whereas the decrease in carbapenem resistance was borderline at the Hungarian center. No significant annual trends were observed at the Turkish center, and the center-by-year interactions were nonsignificant. Exploratory analyses showed lower resistance in 2022-2023 than in 2020-2021 in Hungary but not in Türkiye. CONCLUSION: Resistance patterns in bloodstream P. aeruginosa isolates varied by center, care setting and time. ICU-focused surveillance and locally tailored stewardship strategies may support the management of these infections.