Endophytic Bacteria Enterobacter hormaechei Fabricated Silver Nanoparticles and Their Antimicrobial Activity

Abstract

Antimicrobial resistance (AMR), one of the greatest issues for humankind, draws special attention to the scientists formulating new drugs to prevent it. Great emphasis on the biological synthesis of silver nanoparticles (AgNPs) for utilization in single or combinatorial therapy will open up new avenues to the discovery of new antimicrobial drugs. The purpose of this study was to synthesize AgNPs following a green approach by using an endophytic bacterial strain, Enterobacter hormaechei, and to assess their antimicrobial potential against five pathogenic and four multidrug-resistant (MDR) microbes. UV-Vis spectroscopy, fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), and zeta potential (ζ) were used to characterize the synthesized AgNPs. Endophytic E. hormaechei-mediated AgNPs (Eh-AgNPs) were represented by a strong UV-Vis absorbance peak at 418 nm within 5 min, forming spherical and polydispersed nanoparticles in the size range of 9.91 nm to 92.54 nm. The Eh-AgNPs were moderately stable with a mean ζ value of −19.73 ± 3.94 mV. The presence of amine, amide, and hydroxyl functional groups was observed from FTIR analysis. In comparison to conventional antibiotics, the Eh-AgNPs were more effective against Bacillus cereus (ATCC 10876) and Candida albicans (ATCC 10231), exhibiting 9.14 ± 0.05 mm and 8.24 ± 0.05 mm zones of inhibition (ZOIs), respectively, while displaying effective inhibitory activity with ZOIs ranging from 10.98 ± 0.08 to 13.20 ± 0.07 mm against the MDR bacteria. Eh-AgNP synthesis was rapid and eco-friendly. The results showed that Eh-AgNPs are promising antimicrobial agents that can be used in the development and formulation of new drugs to curb the menace of antimicrobial resistance in pathogenic and MDR microbes.

Antimicrobial Activity of Green Synthesized Copper Nanoparticles (CuNPs) using Aqueous Extract of Psidium Guajava on Clinical Bacteria Isolates.

“…Bands between 3600 and 3200 cm -1 were associated with O-H stretching from phenol, N-H stretching from amide, and C-H stretching at 3000 -2840 cm -1 . Peaks from 2110 cm -1 to 1415 cm -1 were assigned to double bonds of C=C, C=N, C=C=C, C=O, and cyclic carbon (C=C), as well as triple bonds of C≡C and C≡N stretching vibration [38,13,31,37]. Similar peaks were reported within the range of 2110 to 1635 cm -1 , associated with C=C, C=N, C=C=C, C=O, aromatic (C=C), C≡C, and C≡N stretching vibration.…”

Silver and Gold Nanoparticles for Antimicrobial Purposes against Multi-Drug Resistance Bacteria

“…In this assay, Ag NPs synthesis was quick and eco-friendly; compared to traditional antibiotics, the Ag NPs were highly operative against B. cereus , showing about 9 mm and 8 mm zones of inhibition (ZOIs), respectively. These results suggest that these Ag NPs are capable antimicrobial agents that can be applied to the process and formulation of novel drugs to reduce the AMR in pathogenic and MDR microbes [ 11 ].…”

“…AMR describes the resistance of any microbe to the drugs that are applied to kill them. Drug-resistant diseases cause about 0.7 million deaths a year, and if no attempt is made to control it, AMR deaths, at worst, could reach 10 million a year by 2050 [ 11 , 12 , 13 ]. As a result, it can be said that AMR is one of the most important threats to human health and causes an increase in mortality.…”

New Pyrroline Isolated from Antarctic Krill-Derived Actinomycetes Nocardiopsis sp. LX-1 Combining with Molecular Networking

“…Antimicrobial resistance (AMR) has become an increasing problem with the misuse and overuse of antibiotics, causing infections increasingly difficult or impossible to treat with existing drugs [ 24 , 25 , 26 ]. The WHO has declared AMR to be one of the top 10 global public health threats.…”