Antibacterial Effects of HA-Coated Cdsnps and Associated Changes in Stress-Responsive Efflux Gene Expression in MDR Klebsiella Pneumoniae
Year: 2026
Type: article
Abstract: Klebsiella pneumoniae is a global healthcare concern due to its robust efflux systems and ability to form biofilm, especially MDR strains. Our aim was to study the impact of hyaluronic acid-coated cadmium sulfide nanoparticles (CdSNPs-HA) on the expression of bacterial stress-responsive efflux genes. Green method utilizing Raphanus sativus root was used to synthesize the nanoparticles at an elevated temperature. Well diffusion methods were used to assess the minimal inhibitory concentration (MIC), and biofilm formation assays were determined using the 96-microtiter plate. Gene redundancy was identified using PCR, while gene expression was assessed using quantitative PCR (qPCR). The study’s results of SEM and TEM showed a successful HA coating with uniform and stable core-shell rod-like nanostructures. Fifty clinical Klebsiella pneumoniae isolates showed resistance to piperacillin-tazobactam (100%), cefepime (76%), and ceftriaxone (72%). Eighty-six percent of the isolates demonstrated the ability to produce biofilm. PCR results indicated 100% presence of acrB and oqxB efflux pump genes. Antibacterial activity of coated nanoparticles showed enhanced activity compared to uncoated CdSNPs. The MIC of CdSNps-HA was 3.12 mg/mL, compared to 12.5 mg/mL, and a larger inhibition zone was observed (16 mm vs. 13 mm), respectively. RT-qPCR analysis demonstrated more than 6-fold upregulation of acrB and 1.2-fold upregulation of oqxB upon exposure to CdSNPs-HA, compared with downregulation of uncoated nanoparticles. This pattern of regulation reflects a stress-induced response to nanoparticle exposure rather than direct inhibition of efflux. This highlights the complex adaptation of bacteria and suggests that HA-coating influences resistance pathways in a gene-specific manner.
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7170140507