Antibacterial Activity of Phyto-Synthesized Silver Nanoparticles From Dryopteris cristata Against Staphylococcus aureus ATCC 28923 and Escherichia coli ATCC 28922

Emmanuel T Bello; Sunday Awe; Muritala I Bale; Ayoola Awosika; Janet M Oladejo; Faith J Olaitan; Jedidiah E Ikibe

doi:10.7759/cureus.70856

Antibacterial Activity of Phyto-Synthesized Silver Nanoparticles From Dryopteris cristata Against Staphylococcus aureus ATCC 28923 and Escherichia coli ATCC 28922

Cureus. 2024 Oct 4;16(10):e70856. doi: 10.7759/cureus.70856. eCollection 2024 Oct.

Authors

Emmanuel T Bello¹, Sunday Awe², Muritala I Bale³, Ayoola Awosika⁴, Janet M Oladejo⁵, Faith J Olaitan⁶, Jedidiah E Ikibe⁷

Affiliations

¹ Department of Science Laboratory Technology (Microbiology Unit), Newland Polytechnic, Ilorin, NGA.
² Department of Microbiology, Kwara State University, Ilorin, NGA.
³ Department of Microbiology and Parasitology, School of Medicine and Pharmacy, University of Rwanda, Kigali, RWA.
⁴ College of Medicine, University of Illinois Chicago, Chicago, USA.
⁵ Department of Medical Microbiology and Parasitology, University of Ilorin Teaching Hospital, Ilorin, NGA.
⁶ Department of Biological Sciences (Microbiology Unit), Thomas Adewumi University, Oko, NGA.
⁷ Department of Academic Planning, Ojaja University, Ilorin, NGA.

Abstract

Introduction Nanotechnology has emerged as a vital field, particularly in synthesizing nanoparticles. Silver nanoparticles (AgNPs) are recognized for their strong antimicrobial properties against various pathogens, including Staphylococcus aureus and Escherichia coli, due to their small size and high surface area. Green synthesis using plant extracts offers an eco-friendly alternative. The rise of multidrug-resistant bacteria underscores the urgent need for new antimicrobial agents. This study investigates the antibacterial activities of Dryopteris cristata AgNPs (DC-AgNPs) against S. aureus and E. coli, employing antimicrobial susceptibility testing (AST), minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assessments, along with nanoparticle characterization. Materials and method The antimicrobial activity ofDC-AgNPs was evaluated using clinical isolates of E. coli and S. aureus. Bacterial inoculums were standardized to 0.5 MacFarlard (1.5 × 10⁸ CFU/mL) and tested via a modified agar-well diffusion method. The MIC and MBC were determined using broth microdilution and sub-culturing methods, respectively. Characterization of the nanoparticles was conducted using Ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Results and conclusion D. cristata was identified as the plant used to synthesize AgNPs, confirmed by the University of Ilorin, Nigeria. Phytochemical screening revealed the presence of tannins, flavonoids, glycosides, and phenolics. The AgNPs were synthesized by adding the aqueous extract to silver nitrate, resulting in a color change. Characterization via UV-Vis spectrophotometry confirmed nanoparticle formation. Antimicrobial testing showed that DC-AgNPs effectively inhibited S. aureus and E. coli, with minimum inhibitory concentrations of 125 μg and 250 μg, respectively, indicating their potential as antimicrobial agents.

Keywords: antimicrobial resistance; dryopteris cristata; escherichia coli; microbial pathogens; nanotechnology; phytochemicals; staphylococcus aureus.