Inhibitory Effect of Biosynthesized Selenium Nanoparticles on Expression of oqxA efflux pump Gene in Clinical Isolates of Klebsiella pneumonia

Background: Klebsiella pneumoniae is a multidrug-resistant bacterium frequently isolated from urinary tract infections. One of its key resistance mechanisms is the efflux pump gene oqxA, which helps expel antibiotics from the cell. Aim: This study aimed to assess the antibacterial effect of selenium nanoparticles (SeNPs) synthesized using Probiotic bacteria Bacillus subtilis, and to evaluate their impact on oqxA gene expression in K. pneumoniae isolates. Methods: Thirty-four clinical isolates were collected from urine samples and confirmed as K. pneumoniae using biochemical testing and the VITEK 2 system. SeNPs were biologically synthesized and characterized using UV-Vis, FTIR, SEM, TEM, AFM, and XRD. Tests for antibacterial activities were conducted utilizing agar diffusion and minimum inhibitory concentration (MIC) assays. We used real-time quantitative polymerase chain reaction (RT-qPCR) to assess oqxA gene expression both before and after subjecting the cells to SeNPs. Findings: As the concentration of SeNPs was increased, the outcomes demonstrated a definite antibacterial action. A range of 250 to 1000 µg/mL were the MIC values. SeNP therapy significantly decreased expression for oqxA , according to RT-qPCR data. Conclusions: Biosynthesis SeNPs showed promise as a supplementary approach against drug resistance K. pneumoniae due to their powerful antibacterial characteristics and marked reduction of efflux pumps gene activities.