Abstract
This study assessed the antimicrobial efficacy of synthesized zinc oxide nanoparticles produced using aqueous extracts of pomegranate leaves and flowers designated ZnO-NPs-PL, ZnO-NPs-PF. In the study, oxides of zinc were successfully employed to fabricate nanoparticles using extracts from leaves and flowers of pomegranate (Punica granatum). The nanoparticles obtained were characterized spectroscopically. X-ray diffractive analysis (XRD) revealed the elemental components and nature of the synthesized particles. The fabricated zinc oxide nanoparticle (ZnO-NPs) showed a crystalline structure. The morphology of the nanoparticles as shown by scanning electron microscopy (SEM) was unevenly spherical and the functional groups involved in stabilization, reduction and capping were confirmed using Fourier Transform Infra-Red (FT-IR) Spectroscopy. Confirmation of the nanoparticles by UV–Vis analysis showed absorption bands of 284 and 357 nm for pomegranate leaf and flower extract, respectively, mediated ZnO-NPs. Evaluation of the antimicrobial efficacy of the fabricated nanoparticles showed that ZnO-NPs were effective against all selected pathogenic strains, Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae, Salmonella diarizonae, Salmonella typhi, Enterococcus faecalis, Enterococcus faecium, Escherichia coli, Moraxella catarrhalis, Aeromonas hydrophila and Listeria monocytogenes, used in the analysis. The effectiveness of these nanoparticles could be linked to their sizes and shapes as obtained using a transmission electron microscope (TEM) and scanning electron microscope (SEM). Our reports revealed that increasing the concentration of the nanoparticles resulted in an increase in the antibacterial activity exerted by the nanoparticles, thus suggesting that both ZnO-NPs can effectively be used as alternative antibacterial agents. Further research is required to assess their mechanisms of action and toxicity.
Highlights
Bacterial pathogens cause infections that are typically treated using antibiotics [1,2]
transmission electron microscope (TEM) micrographs micrographs of of nanoparticles nanoparticles showed showed that that ZnO-NPs-PL
From the zones of inhibition obtained, the zinc oxide produced from leaf and flower extracts showed consistency, inhibiting all bacterial strains used in the analysis
Summary
Bacterial pathogens cause infections that are typically treated using antibiotics [1,2]. Antibiotics are antibacterial agents that inhibit the growth of bacterial pathogens through diffident modes of action ranging from inhibition of enzyme action to interfering with DNA, RNA and protein synthesis [3]. These processes result in the disruption of the bacterial cell membrane structure, leading to cell death [2,3]. The ever-increasing occurrence of bacterial resistance among pathogenic bacteria that is most often caused by the inappropriate or misuse of antibiotics [10], coupled with limited surveillance data as well as the recent increase in biofilm-associated infections in humans, has led to the search for more effective agents and strategies to combat antimicrobial resistance [11,12] Contrary to the modes of action of antibiotics, bacterial strains are able to express antimicrobial resistance by: Molecules 2020, 25, 4521; doi:10.3390/molecules25194521 www.mdpi.com/journal/molecules (1) altering the target of antibiotics by expressing genes that code for an alternate version of the antibiotic target [6,7,8]; (2) developing enzymes that can degrade or modify the drug [1,8]; (3) ensuring reduced uptake of antimicrobial drugs or acting as efflux pumps that push out the drugs [3,6]; and (4) formation of biofilm layers around the bacterial cell, limiting or reducing its exposure to antibiotics [8,9].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
