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 (Cr 2 O 3 ) nanoparticles were synthesized by the photochemical method. The morphology, topographic and physical properties of nanosynthesized 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 Cr 2 O 3 -NPs was to be ranging from 11 to 30 nm. The activities of the Cr 2 O 3 -NPs for antibacterial and antibiofilm formation against persistent K. pneumoniae were assessed. The result showed a significant inhibitory effect of Cr 2 O 3 -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 Cr 2 O 3 -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. Cr 2 O 3 -NPs therefore had a positive impact on biofilms that were produced by persistence isolates of K. pneumoniae.

A NOVEL series of 3,5-Disubstituted-4,5-Dihydro-1H-pyrazoles (3-9) containing imine moiety were synthesized and characterized using spectral analysis. The synthesized derivatives were In vitro screened against several bacterial species, Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacterbaumannii as well as Candida albicans and revealed moderate to potent activity. The antioxidant study was confirmed for the synthesized derivatives against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical qualitatively using TLC technique, and quantitatively by spectrophotometric method. The half maximal inhibitory concentration (IC 50) was calculated for the active compounds (1-5, 8). Docking study for the potent compounds (2 and 4) against glucosamine-6-phosphate synthase, the target enzyme for the antimicrobial agents, was explored to explain the interactions of the discovered hits within the amino acid residues of the enzyme active side. The docking parameters enhanced the activity of new compounds as promising antimicrobial agents.