Bacteriologically Derived Copper Nanoparticles as Novel Arsenal Against Multidrug-Resistant Pathogens.

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Microbiology

Background:

• Antimicrobial resistance (AMR) is a growing global health crisis driven by the injudicious use of antibiotics.
• There is an urgent need for novel antimicrobial agents to treat multi-drug resistant (MDR) infections.
• Green synthesis of nanoparticles offers a sustainable approach to developing new therapeutic agents.

Purpose of the Study:

• To synthesize novel green copper nanoparticles (BS-CuNPs) using cell-free extracts of Bacillus subtilis.
• To evaluate the bactericidal efficacy of BS-CuNPs against various MDR pathogenic bacteria.
• To investigate the antioxidant properties of BS-CuNPs.

Main Methods:

• Green synthesis of copper nanoparticles (BS-CuNPs) using Bacillus subtilis (MTCC 441) cell-free extracts.
• Transmission Electron Microscopy (TEM) for nanoparticle characterization (size, morphology).
• Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays against MDR bacteria.
• DPPH and H2O2 radical scavenging assays to determine antioxidant activity (IC50, IC90 values).

Main Results:

• BS-CuNPs were synthesized with a spherical configuration, measuring 11.47 ± 2.6 nm.
• Excellent colloidal and thermal stability of BS-CuNPs was confirmed by zeta potential and TGA.
• BS-CuNPs exhibited potent antimicrobial activity against MDR bacteria (MICs ≤ 0.625 mg/ml), with significant efficacy against Enterobacter cloacae Bu59 (MIC 0.156 mg/ml).
• BS-CuNPs demonstrated strong antioxidant activity, with lower IC50 and IC90 values in DPPH assays compared to chemically synthesized CuNPs.

Conclusions:

• Biogenic BS-CuNPs represent a novel and effective antimicrobial agent.
• The study highlights the potential of green synthesized nanoparticles in combating AMR.
• BS-CuNPs show promise for applications in biomedicine due to their antimicrobial and antioxidant properties.