ZnO NPs showed both antibacterial and antibiofilm efficacy against drug-resistant strains of E. coli, K. pneumoniae, and S. aureus and completely eradicated E. coli biofilm in combination with gentamicin.
Abstract
Background: Gram-negative bacteria resistant to multiple drugs are a major cause of illness and death worldwide. Their remarkable capacity to develop resistance to antibiotics makes them a serious concern in medical practice. Methods: A simple, green, novel method is used to synthesize ZnO nanoparticles (ZnO NPs) using ethanolic extracts of Diplazium esculentum via precipitation. Results: ZnO NPs exhibit a hexagonal structure with a particle size of ~30 nm and a band gap of 3.24 eV. The defect sites formed in ZnO NPs were estimated using prominent peaks in the photoluminescence spectra. ZnO NPs displayed a more than 4-log reduction in multi-drug-resistant E. coli and K. pneumoniae clinical isolates at a 500 μg/mL concentration. Moreover, ZnO NPs significantly reduced the biofilm bacterial cell viability of clinical isolates of Gram-negative bacteria. Complete eradication of biofilms was achieved for drug-resistant E. coli clinical isolates using a combination of sub-MIC of gentamicin and 500 μg/mL ZnO NPs. Green-synthesized ZnO NPs did not induce oxidative stress in mice, as indicated by unchanged GST, GSH, and thiol levels across all the tested organs. ZnO NPs showed both antibacterial and antibiofilm efficacy against drug-resistant strains of E. coli, K. pneumoniae, and S. aureus and completely eradicated E. coli biofilm in combination with gentamicin. Conclusions: Our study focuses on the sustainable synthesis of biocompatible ZnO NPs for the treatment of infections caused by pathogens belonging to the high-priority ESKAPE group.
It is suggested that biogenically synthesized MgO NPs hold considerable promise as antibacterial and antibiofilm agents against MDR Gram-negative pathogens.
Rafia Anwer, Safdar Ali, Muhammad Shahid Mehmood et al.· International Microbiology· 0 citations
Results show that green-synthesized ZnO nanoparticles have strong antibacterial and antibiofilm potential and can boost the effectiveness of traditional antibiotics, indicating their potential as supplemental agents in MDR bacterial infection management strategies.
Jazab Naeem, Muhammad Mubeen Ahmad, Syed Kashif Raza et al.· Bulletin of University of Ag...· 0 citations
Findings highlight ZnONPs as a promising, low-cost alternative for managing MRSA infections, particularly in biofilm-associated cases, warranting further clinical exploration in resource-limited settings.
The rapid emergence of multidrug-resistant Staphylococcus aureus (MRSA), specifically, methicillin-resistant strains, has become a global health concern. Biofilm-forming ability, enhanced virulence and resistance to multiple antibiotics have challenged treatment strategies. Therefore, immediate attention is necessary to design alternative therapeutic strategies including nanotechnology-based solutions, novel drug targets, and anti-virulence strategies, to combat this global public health threat. Findings of this study elucidates the binding interaction and inhibition potential of zinc oxide nanoparticles (ZnONPs) biosynthesized using an endophytic isolate obtained from Hibiscus rosa-sinensis and identified as Penicillium citrinum using morphology and ITS rRNA gene sequencing. The comprehensive characterization of biosynthesized ZnONPs was done using UV- visible spectrophotometry, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS) and zeta potential analysis. XRD and TEM analyses revealed the ZnONPs with spherical to elliptical shape with mean size of ~58 nm. The FTIR analysis confirmed the functional groups responsible for stabilizing and capping of ZnONPs. The biosynthesized ZnONPs displayed colloidal stability with a mean hydrodynamic diameter of 240.4 nm with a ζ-potential of −13 mV, as revealed in Dynamic light scattering (DLS) studies. The anti-staphylococcal studies of ZnONPs revealed an excellent antibacterial activity (22 ± 1.42) with a minimum inhibitory concentration (MIC) of 1000 µg/mL and demonstrated time-dependent bactericidal effects as revealed in time-kill assay. In addition, ZnONPs inhibited biofilm formation in a concentration-dependent manner, with highest reduction (68.7% ± 1.12%) in biofilm biomass, as revealed in a dye-based assay, accompanied by suppression of metabolic activity in biofilm-embedded cells. Importantly, ZnONPs displayed excellent inhibitory activities against the key virulence-associated exoenzymes, including lipase (IC₅₀ ≈ 380 ± 1.12) and hyaluronidase (IC₅₀ ≈ 330 ± 1.12 µg/mL). The cytotoxicity assessment using human red blood cells (hRBCs) revealed negligible haemolytic activity (< 2%) at biologically effective concentrations, confirming their safety and hemocompatibility. Considering the green synthesis, biocompatible nature and outstanding anti-staphylococcal potential, the endophyte derived ZnONPs showcases their potential as a sustainable nanotechnology-based alternative to conventional antimicrobial strategies against biofilm-associated infections of S. aureus.
Amruta A. Joshi, V. M. Songire, Ravindra H. Patil· Bioscience Nanotechnology· 1 citation
It is suggested that SVM is a promising candidate for combination therapy, warranting further investigation with surface-functionalized formulations to improve its selectivity.
Juliane Zacour Marinho, Luiz Felipe Carreiro Machado, I. P. Ceravolo et al.· GAZI UNIVERSITY JOURNAL OF S...· 0 citations
