A Multicenter Surveillance of Antimicrobial Resistance Among Pseudomonas aeruginosa in Hospitals of the Greater Accra Region of Ghana.

BACKGROUND Carbapenem-resistant Pseudomonas aeruginosa (CRPA) and multidrug-resistant (MDR) P. aeruginosa limit therapeutic options but have been sparsely documented in Ghana.

METHODS From November 2023 to December 2024, we conducted a prospective cross-sectional study of P. aeruginosa isolates from acute-care hospitals in Greater Accra, Ghana. Isolates were identified by matrix-assisted laser desorption ionization-time of flight, and antimicrobial susceptibility was assessed by disk diffusion as per Clinical Laboratory Standard Institute guidelines. Meropenem-resistant isolates with positive carbapenemase phenotype were subjected to whole-genome sequencing. Multivariable logistic regression models identified risk factors for infections caused by MDR and carbapenemase-producing Pseudomonas aeruginosa (CRPA).

RESULTS P. aeruginosa accounted for 0.32% (n = 267/83,589) of all bacterial infections identified from submitted clinical specimens and 2.82% (n = 267/12,236) of culture-positive infections. Of the 267 P. aeruginosa isolates, 20.2% (n = 54/267) were MDR and 13.5% (n = 36/267) were CRPA. Amikacin retained the highest activity against P. aeruginosa. The mean multiple antibiotic resistance index among MDR isolates (0.51 ± 0.26) was significantly higher than that among non-MDR P.aeruginosa isolates (0.02 ± 0.07; p < 0.001), with a large between-group difference (Hedges' g = 3.70). Only one isolate (2.7%) harbored a single carbapenemase gene, blaNDM-1. The remaining 35 carried a blaOXA-50-type backbone that co-occurred with either class A carbapenemases (blaKPC [n = 7], blaSME-1 [n = 4], blaGES-5 [n = 1]) or class B metallo-β-lactamases (blaNDM-1 [n = 19], blaVIM-5 [n = 3], blaIMP-15 [n = 1]). blaNDM-1 was the most dominant carbapenemase gene (n = 20/36) . Wound infection was the strongest predictor of MDR infections (adjusted odds ratio [aOR] = 3.01; 95% confidence interval (CI) = 1.43-4.47; p = 0.001], whereas inpatient status was the strongest predictor of CRPA infection (aOR = 3.32; 95% CI = 0.98-4.09; p = 0.001).

CONCLUSIONS MDR P. aeruginosa and carbapenem Resistant P.aeruginosa (CRPA), mostly blaNDM-1 producers, are major causes of infection in our setting. Restricting carbapenem use through stewardship and strengthening infection control is essential to limit CRPA spread.