Synthesis and Evaluation of Antimicrobial Activities of Gold and ZnO Nanoparticles on Inhibiting the MexAB-OprM Efflux Pump in Pseudomonas aeruginosa Isolates

One of the problems in treating burn patients is the emergence of antibiotic resistance with various mechanisms. Mex pumps play a significant role in resistance to antimicrobial drugs in bacteria. The aim of this study was to investigate the effects of nanoparticles of gold and ZnO on inhibiting the expression of the MexAB-OprM efflux pump in Pseudomonas aeruginosa. Gold and ZnO nanoparticles were prepared with the chemical reduction method and characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The antimicrobial activities of gold and ZnO nanoparticles on inhibiting the MexAB-OprM efflux pump in Pseudomonas aeruginosa isolates were investigated by real-time PCR assay. In this study, from 200 swab specimens from burn patients collected in Qom hospitals, 89 (44.5%) samples were infected with Pseudomonas aeruginosa, of which 19 cases (31%) were resistant to ciprofloxacin, and 54.72% and 34.23% had the MexA and MexB gene, respectively. The expression levels of MexA and MexB genes did not significantly reduce in the presence of the nanoparticles in real-time PCR. Gold and zinc nanoparticles had no effect on the inhibition of the efflux pump in Pseudomonas aeruginosa strains isolated from burn patients.