Epidemiology and multidrug resistance of Pseudomonas aeruginosa: A decade of surveillance at a Tunisian Hospital

Background: Pseudomonas aeruginosa is the type species of Pseudomonas genus, known for the diversity of its virulence factors that cause widespread community-acquired infections. This study aimed to describe on the epidemiology of P. aeruginosa infections and to report the emergence of antibiotic resistance in a Tunisian University Hospital. Methods: This retrospective study included all P. aeruginosa strains gathered in a Tunisian University Hospital over 11 years. Bacterial identification was conducted using conventional methods and CA-SFM guidelines were followed to test antibiotic susceptibility. Results: During the study period, 2651 P. aeruginosa strains were collected. The majority of these strains originated from surgery departments (38%) and intensive care units (29%). These strains were most commonly identified from pus (44%) and respiratory samples (30%). Antibiotic resistance rates were high: imipenem (38%), ticarcillin (34%), piperacillin (33%), ticarcillin-clavulanic acid (31%), and levofloxacin (31%). Colistin and amikacin were antibiotics with the most preserved activity. Of the 2,651 isolates, 707 (26%) were multidrug-resistant, mainly from intensive care (43%, N=306) and surgical units (29%, N=203). Conclusion: Pseudomonas aeruginosa has mostly been found in surgical and intensive care units. The emerging antibiotic resistance highlights the crucial importance of preventive hygiene measures and the implementation of a strong infection surveillance system within hospital settings to better manage the spread of these infections.