Global high-risk clones and multidrug-resistant serotype strains of Pseudomonas aeruginosa from surgical site infections in low-resource settings

Surgical site infections (SSIs) caused by Pseudomonas aeruginosa pose significant challenges in healthcare, particularly in low and middle-income countries (LMICs). Understanding the genomic characteristics and antimicrobial resistance profiles of P. aeruginosa isolates is crucial for informing appropriate treatment and guiding infection prevention and control strategies. P. aeruginosa isolates recovered from SSIs were analyzed using whole-genome sequencing and antimicrobial susceptibility testing. The isolates were identified using matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-ToF MS) system, and their antibiotic susceptibilities were determined using the Kirby–Bauer disk diffusion method and interpreted with Clinical and Laboratory Standards Institute guidelines. Whole-genome sequencing was performed using the Illumina MiSeq platform, and sequence data were analyzed using free online bioinformatics tools, including CARD-RGI, ResFinder, PAst, VFDB, and MLST. Between July 2018 and September 2023, 563 patients were enrolled in a surgical site infection study, which led to the recovery of 82 P. aeruginosa isolates. The isolates were resistant to ciprofloxacin (n = 23, 28.05%), gentamicin (n = 20, 24.39%), piperacillin-tazobactam (n = 13, 15.85%), cefepime (n = 12, 14.63%), ceftazidime (n = 12, 14.63%), meropenem (n = 10, 12.20%), and amikacin (n = 8, 9.76%). Multidrug resistance was noted in 10 isolates (12.20%), with three isolates resistant to all antibiotics tested (n = 3, 3.7%). Sequence data revealed international high-risk clones: ST308 and ST773 (n = 5 each, 6.10%), ST244 (n = 4, 4.88%), ST446, ST357, and ST654 (n = 2 each, 2.44%), and ST235 (n = 1, 1.41%). Newly identified sequence types ST4287, ST4288, ST4289, ST4521, ST4522, ST4523, and ST4524 were also detected. Serotype O11 (n = 28, 34.15%) was the most prevalent, followed by O5, O6, and O4. Key virulence genes, such as algD, lasB, exoS, plcH, toxA, and plcN, were also detected. The identification of both high-risk and novel clones, coupled with diverse resistance and virulence factors, underscores the need for continuous surveillance of circulating strains. Employing advanced technologies, such as whole-genome sequencing, is essential for guiding infection control and treatment strategies in Ghanaian hospital settings.