Pattern of cephalosporin and carbapenem-resistant Pseudomonas aeruginosa: a retrospective analysis

•1815 clinical isolates were identified•160 (9%) were resistant to carbapenems and cephalosporins•93.6% of multidrug-resistant Pseudomonas aeruginosa were negative for carbapenemase genes•The most common resistance was among blood isolates (P-value < 0.00001) Despite its financial cost on the world's health care system, Pseudomonas aeruginosa antibiotic resistance has been increasing. Therefore, the goal of this study was to assess the level of antimicrobial resistance to anti-pseudomonas medicines, specifically β-lactam medications such as cephalosporin and carbapenems. In addition, we evaluate the prevalence of multi-drug resistance to P. aeruginosa, particularly during the years of the COVID-19 pandemic. This retrospective analysis covered the period from January 2019 to December 2022 and included cephalosporin- and carbapenem-resistant P. aeruginosa isolates. The real-time polymerase chain reaction Genexpert test (CARBA-R kit) was used for the detection of genes responsible for carbapenemase resistance. During the time of the study, 1815 clinical isolates of P. aeruginosa were identified and 160 (9%) were resistant to carbapenems and cephalosporins. The resistance rates were 32.5% (13/597) in 2019, 11.2% (44/393) in 2020, 7% (26/369) in 2021, and 11% (50/456) in 2022. Of those isolates, multidrug-resistant rates were 6.7%, 86.3%, 57.7%, and 56%, per year over the study period. Using Genexpert test, 88 (93.6%) of multidrug-resistant P. aeruginosa were negative for carbapenemase genes. This study emphasizes the alarming patterns of carbapenem and cephalosporin resistance among P. aeruginosa clinical isolates. Furhter surviellance from different centers and different regions is required.