ASO-functionalized gold nanoparticles for gene silencing in drug-resistant Pseudomonas aeruginosa: a proof-of-concept study

The present work aims at evaluating a novel therapeutic technique against clinical samples of Pseudomonas aeruginosa, a multiple drug resistant bacterium by integrating gold nanoparticles (AuNPs) with antisense oligonucleotide (ASO) (ASO-AuNPs) to target and silence the blaVIM and blaCTX-M genes. The objectives were to evaluate the ability of ASO-AuNPs to silence resistance genes and reduce their expression to combat antibiotic resistance. Seventy P. aeruginosa clinical isolates collected from Iraqi hospitals were isolated, identified and their antibiotic resistance profiles were assessed. The blaVIM and blaCTX-M genes were detected by PCR. These genes were engineered through the use of ASO-AuNPs. Resistance to carbapenem and cephalosporin and quantitative blaVIM and blaCTX-M gene expression in P. aeruginosa were further studied before and after silencing. The blaVIM gene was found in 79.2% of carbapenem-resistant samples, while blaCTX-M was identified in 72.7% of cephalosporin-resistant samples. A significant reduction in antibiotic resistance was achieved following ASO-AuNPs application. Moreover, the gene silencing technique significantly decreased the expression of blaVIM and blaCTX-M genes. The mean fold change of the CTX-M gene was 15.92 before and 1.36 after gene silencing, that of the blaVIM gene was 0.63 and 0.51, respectively. These findings provide a proof-of-concept for the use of ASO-functionalized gold nanoparticles as a potential strategy for targeting antibiotic resistance genes in P. aeruginosa, with potential applications in managing resistant infections in healthcare settings.