“Synergistic Research Into The Antimicrobial Behavior of Copper Oxide Nanoparticles (CuO NPs) against Escherichia coli, Staphylococcus aureus, and Ascochyta fabae”

Abstract

The present study was performed to evaluate the antibacterial and antifungal activity of four different
concentrations (25%, 50%, 75%, and 100%) of copper oxide nanoparticles (CuO-NPs) against three
pathogens (Escherichia coli, Staphylococcus aureus, and Ascochyta fabae). There are various methods to
synthesize metallic nanoparticles (NPs), including chemical, physical, and biological processes. In this study,
Bacillus sp. FU4 was used as a biological source for the biosynthesis of CuO NPs. The synergistic
antibacterial and antifungal activity of the copper oxide nanoparticles was tested on gram-negative and grampositive bacteria, Escherichia coli (ATCC25922), Staphylococcus aureus (ATCC 43300), and the fungus
Ascochyta fabae (ATCC38599) using the well diffusion, poison food and microdilution methods. It is known
that the synergistic effects of transition metal-based nanocomposites have enhanced antimicrobial activities.
CuO NPs were prepared using copper sulfate (CuSO4). CuO NPs were formed after the oxidation of Cu NPs.
The average effect of CuSO4 concentration (0.1, 0.01, and 0.001 M), incubation, and cultivation time (48, 72,
96 hours) as three-level controllable factors were evaluated in the biosynthesis of CuO NPs. The
characterization of CuO NPs was determined by Fourier transforms infrared spectroscopy (FT-IR).
Furthermore, the antimicrobial properties of CuO NPs were investigated with Escherichia coli ATCC 25922
and Staphylococcus aureus ATCC 43300 as multidrug-resistant (MDR) bacteria. Although antibiotics can
treat most bacterial infections, increasing microbial resistance is limiting the benefits of antibacterial agents
in fighting infectious diseases. The threat posed by copper oxide nanoparticles prompts the search for
alternative approaches to treating bacterial infections. Recently, copper oxide nanoparticles have been
extensively studied for their application in combating microbial infections. This research attempts to briefly
summarize the current studies on the antibacterial properties of copper oxide nanoparticles.
The following was evaluated: The size distributions of the NPs ranged from 2–41 nm with spherical shapes.
The antimicrobial activities of CuO NPs were measured by inhibition zone diameter in disc diffusion assays
of NPs dispersed in batch cultures. Two concentrations of CuSO4 (0.1 and 0.01 M) had an antibacterial effect
on E. coli (330.57 and 6.2 mm). In the case of S. aureus, surprisingly, there were no signs of growth. This
research shows that copper nanoparticles have strong antimicrobial activities and can be used to control and
treat various infectious diseases in the future. The antifungal activity of ethanol extract of CuO nanoparticles
was calculated against isolated phytopathogenic fungi by the evaluation using the poisoned food method.
It emerged that the synthesized CuO nanoparticles were highly efficient against Ascochyta fabae. To
understand the antifungal activity of CuO-based nanoparticles along with the detailed mechanism the
morphological analysis using microscopic instruments is believed to play an important role. Various
microscopic techniques like SEM, and TEM give detailed information about nanoparticles. Copper oxide
nanoparticles (CuO-NPs) showed excellent antimicrobial activity against different bacterial and fungal strains
(Escherichia coli, Staphylococcus aureus, and Ascochyta fabae). Possible mechanisms of the antimicrobial
activity of CuO NPs should be further investigated. CuO NPs have an antibacterial activity that may be
beneficial in the medical field in combating prominent pathogens such as Escherichia coli (ATCC25922),
Staphylococcus aureus (ATCC 43300), and the fungus Ascochyta fabae (ATCC38599)