Evaluation of Gene Expression of Staphylococcus Aureus Biofilm (ica) by the Effect of Iron Oxide Nanoparticles by Real Time PCR method

Abstract

Biofilm formation is one of the key virulence factors of Staphylococcus aureus, contributing significantly to its ability to cause infections. Recent research has demonstrated that biofilms act as protective barriers, reducing the efficacy of antibiotics and complicating treatment efforts. The use of nanoparticles, particularly as alternatives to conventional drugs, has gained attention for their potential to inhibit biofilm formation. In this study, 60 S. aureus strains were isolated from wound samples and confirmed through morphological identification. Biofilm production was assessed using the Microtiter Plate (MTP) method. The presence of target genes was determined using PCR, and the minimum inhibitory concentration (MIC) of iron oxide nanoparticles was measured. To evaluate the impact of sub-MIC concentrations on gene expression, the expression level of the icaC gene—associated with biofilm formation—was analyzed using Rotor-Gene and REST software. Among the isolated strains, 16.66% were weak biofilm producers, 48.33% moderate, and 35.01% strong producers. The efficacy of iron oxide nanoparticles was tested on the 21 strains classified as strong biofilm formers. Compared to untreated controls, all treated strains exhibited increased Ct values, and the fold change in icaC gene expression was -3.88, indicating significant downregulation Given the inhibitory effect of iron oxide nanoparticles on icaC, a key gene in biofilm formation, these nanoparticles show promise as potential therapeutic agents to combat Staphylococcus aureus infections and suppress biofilm-associated virulence.