Association of carbapenem and multidrug resistance with the expression of efflux pump-encoding genes in Pseudomonas aeruginosa clinical isolates
Shaghayegh Yousefi, Maryam Nazari, Rashid Ramazanzadeh, Amirhossein Sahebkar, Elham Safarzadeh, Farzad Khademi
Abstract
Efflux pumps play an important role in the emergence of antibiotic-resistant Pseudomonas aeruginosa strains. The present study aimed to assess the expression of the MexAB-OprM, MexCD-OprJ, MexEF-OprN, and MexXY-OprM efflux pumps in carbapenem-resistant and multidrug-resistant (MDR) P. aeruginosa strains isolated from clinical specimens between June 2019 and January 2022 in Ardabil city. The presence of efflux pump-encoding genes, i.e. mexA, mexC, mexE, and mexY, was assessed using the polymerase chain reaction (PCR) technique in 48 carbapenem-resistant and MDR P. aeruginosa strains. Real-time reverse transcription PCR was employed to evaluate the expression levels of mexA, mexC, mexE, and mexY genes. All 48 carbapenem-resistant and MDR P. aeruginosa strains harbored efflux pump-encoding genes including mexA, mexC, mexE, and mexY according to the PCR results. Overexpression of the MexAB-OprM, MexCD-OprJ, MexEF-OprN, and MexXY-OprM efflux pumps was detected in 75% (n = 36), 83.3% (n = 40), 10.4% (n = 5) and 41.6% (n = 20) of the clinical isolates of P. aeruginosa, respectively. This study revealed that the presence and overexpression of efflux pumps are associated with the emergence of carbapenem-resistant and MDR P. aeruginosa strains. Therefore, research on efflux pump inhibitors of P. aeruginosa will be a worthwhile endeavor to increase the clinical efficiency of available antibiotics and prevent ensuing treatment failure.