Effect of Gold-conjugated Nanoparticle siRNA on Efflux Pump MexB Gene Expression in Clinical Isolates of Pseudomonas aeruginosa

Background: Pseudomonas aeruginosa is a prevalent nosocomial infection associated with significant mortality rates. Microorganisms, such as P. aeruginosa , possess the capacity to acquire a significant level of resistance to many drugs. The MexAB-OprM system, which exhibits significant levels of expression, is considered one of the most prominent efflux pumps associated with multi-drug resistance. Aim: The aim of this study was to reduce the gene expression of efflux pump in P. aeruginosa. In this study we used gold-conjugated nanoparticle siRNA against MexB gene, then we determined the phenotypic change in efflux pump activity and the level of gene expression after the gene silencing method. Materials and Methods: This study examined seven strains of P. aeruginosa isolated from patients admitted to various hospitals in Baghdad, which identify by the Vitek compact 2 system; then we have created a 34-bp single-strand siRNA loaded on gold nanoparticles (AuNPLs). The Ethidium Bromide-Cartwheel Test (EtBr-CW) method was used to assess changes in the phenotype of efflux pump activity in response to siRNA. The expression of MexB mRNA was examined using RT-PCR to determine if the siRNA has impacted on efflux pump activity. Results: The results of this study demonstrate that the utilization of siRNAs loaded on AuNPLs led to a reduction in phenotypic efflux pump activity in six isolates, with just one isolate exhibiting persistent active (positive) efflux pump activity. The mRNA expression level of the MexB gene exhibited a decrease in fold change 2 -ΔΔCT in P. aeruginosa clinical isolates (67, 49, PDR5, 44, 5, and 66) when examined in vitro . The specific fold change values observed were 0.104, 0.031, 0.029, 0.169, 0.747, and 0.005, respectively. Conclusion: Since the efflux pump is one of the mechanisms for antibiotic resistance in P. aeruginosa , targeting the MexB gene using gold-conjugated nanoparticle siRNA may be a creative way to lessen P. aeruginosa resistance to a variety of antibiotics.