Impact of Chromium Oxide Nanoparticles on Growth and Biofilm Formation of Persistence Klebsiella pneumoniae Isolates

Bacterial persistence is recognized as a major cause of antibiotic therapy failure, causing biofilms and chronic intractable infections. The emergence of persisters in K. pneumoniae isolates has become a worldwide public health concern. Despite this clinical threat, currently, there are no viable means for eradicating K. pneumoniae persisters. In this project, chromium oxide (Cr₂O₃) nanoparticles were synthesized by the photochemical method. The morphology, topographic and physical properties of nano-synthesized were described by transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray powder diffraction (XRD), and ultraviolet-visible spectroscopy (UV.vis) measurements. The obtained average size of Cr₂O₃-NPs was to be ranging from 11 to 30 nm. The activities of the Cr₂O₃-NPs for antibacterial and antibiofilm formation against persistent K. pneumoniae were assessed. The result showed a significant inhibitory effect of Cr2O3-NPs against K. pneumoniae. A, where the zones of inhibition were 12–18 mm, and the minimum inhibitory concentration (MIC) was 625 μg/mL. The concentration of Cr2O3-NPs of 10 mg/mL demonstrated the highest inhibition activity against biofilm formation (73.95 ± 2.17%), indicating the lowest inhibition (19.08 ± 1.32%) at a level of 0.625 mg/mL. Cr₂O₃-NPs therefore had a positive impact on biofilms that were produced by persistence isolates of K. pneumoniae.