Hydrothermal synthesis of silver vanadate nanoparticles, antimicrobial and anti-inflammatory potentials, cytotoxicity and interference on the activity of antimicrobial drugs

Green Synthesized Zinc Oxide Nanoparticles as Antibacterial and Antibiofilm Agents against Multidrug-Resistant ESKAPE Pathogens

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.

Gramicidin D as a Multi-Target Antimicrobial Against Staphylococcus aureus: Biofilm Disruption, Virulence Attenuation, Antibiotic Potentiation, and Protein-Peptide Docking Insight.

The Antibacterial Activity of Silver Nanoparticles against Pathogenic Bacteria is dependent on their Size, Shape, and Surface Properties.

The global increase in antimicrobial resistance (AMR) has led researchers to focus on silver nanoparticles (AgNPs) as potential antimicrobial agents. The present study used a multi-synthesis approach to obtain AgNPs of different size, shape, and surface properties (SSSP), and compared the effect of SSSP on the antibacterial activity of these AgNPs in combination with antibiotics. The two plant-synthesized quasi-spherical AgNPs (7.36 nm, 12.53 nm) showed better antimicrobial activity against multiple antibiotic-resistant (MAR) bacteria compared to microbially-synthesized quasi-spherical AgNPs (11.71 nm) or the larger chemically-synthesized spherical (17.65 nm) and hexagonal AgNPs (57.36 nm). When these plant-synthesized AgNPs were used along with antibiotics as silver nanoparticle-antibiotic combinations (SACs) and tested against vancomycin-resistant Staphylococcus aureus (VRSA) and MAR Acinetobacter baumannii (MAB), the smaller fatty acid-capped AgNPs showed better synergistic antibacterial activity than the larger protein-capped AgNPs. The AgNPs did not show any in-vitro cytotoxicity against normal mammalian Vero cells at effective antibacterial concentrations. The SACs displayed potent anti-biofilm activity against VRSA and MAB and caused leakage of the cytoplasmic contents, suggestive of loss of membrane integrity of the bacterial cells. The anti-biofilm activity of the SACs suggests that the plant-based AgNPs might be able to reduce pathogenesis of even highly resistant bacteria. Thus, the present study indicates that by modifying SSSPs of AgNPs, it may be possible to generate effective AgNP-based antimicrobial agents against highly resistant microorganisms.

Preparation and Physicochemical Characterization of Chitosan-Coated Iron Oxide Nanoparticles Conjugated with Oxacillin: Antimicrobial, Antibiofilm, and Biocompatibility Activities against MRSA Staphylococcus aureus.

The growing threat of antimicrobial resistance and biofilm-associated infections has critically undermined the efficacy of conventional antibiotics. Methicillin-resistant Staphylococcus aureus (MRSA) represents a clinically significant multidrug-resistant pathogen renowned for its capacity to form protective biofilms that confer resistance to therapeutic agents. The present study investigated a nanocomposite system comprising chitosan-coated iron oxide nanoparticles conjugated with oxacillin (IONPs-CS-OXA) with the aim of enhancing antimicrobial and antibiofilm efficacy against MRSA. Iron oxide nanoparticles were synthesized via chemical co-precipitation, subsequently coated with chitosan, and conjugated with oxacillin. The nanocomposite was characterized by UV-Vis spectroscopy, FT-IR, XRD, zeta potential analysis, DLS, FE-SEM, and TEM. Multidrug-resistant MRSA isolates obtained from clinical specimens were subjected to antibiotic susceptibility testing, biofilm quantification, minimum inhibitory concentration (MIC) determination, and assessment of antimicrobial and antibiofilm activity. Biocompatibility was evaluated via MTT assays using HdFn and WRL-68 cell lines. Physicochemical characterization confirmed the successful fabrication of spherical IONPs-CS-OXA nanoparticles with nanoscale dimensions and a stable surface charge. MRSA isolates demonstrated high resistance to multiple antibiotics, including oxacillin. The nanocomposite markedly enhanced antimicrobial efficacy, as evidenced by significantly lower MIC values relative to free oxacillin. Inhibition zones were notably enlarged against tested MRSA strains, while biofilm formation was reduced by 54-88%. Cytotoxicity assays confirmed minimal adverse effects on normal cells, with cell viability exceeding 80%. The synergistic interaction among chitosan, iron oxide nanoparticles, and oxacillin conferred enhanced antibacterial and antibiofilm performance alongside acceptable biocompatibility. The IONPs-CS-OXA nanocomposite constitutes a promising candidate platform that, subject to further validation, may augment antibiotic delivery and help combat multidrug-resistant MRSA infections.

Antibiofilm potential of biogenic magnesium oxide nanoparticles against multidrug resistant gram-negative bacteria.

It is suggested that biogenically synthesized MgO NPs hold considerable promise as antibacterial and antibiofilm agents against MDR Gram-negative pathogens.

Exploitation of Nanoparticle–Essential Oil Combinations to Enhance the Efficacy of Antimicrobial Agents Against Staphylococcus equorum

Background: This study evaluated the antibacterial, antibiofilm, and biofilm eradication activities of biogenically synthesized silver nanoparticles (AgNPs-L, AgNPs-R) mediated by extracts of Lavandula angustifolia and Salvia rosmarinus, individually and in combination with their respective essential oils (EOs) and ampicillin (AMP), against a multidrug-resistant biofilm-forming Staphylococcus equorum strain. Physicochemical characterization confirmed the successful biosynthesis of spherical AgNPs-L (10–25 nm) and AgNPs-R (5–15 nm). Individual treatments exhibited distinct antibacterial activity, with MIC values of 25 µg/mL for AgNPs-L, 12.5 µg/mL for AgNPs-R, and 0.1% (v/v) for both EOs; however, they showed no ability to eradicate preformed biofilms. Dual AgNPs/EO combinations at subinhibitory concentrations demonstrated borderline additive effects (FICI = 0.501) and significantly potentiated antibacterial and antibiofilm activity compared with individual treatments. Triple AgNPs/EO/AMP combinations exhibited the most pronounced biological effects, with predominantly additive interactions depending on AMP concentration. Lavender-based triple combinations achieved up to 63.9% inhibition of planktonic growth, 78.1% prevention of biofilm formation, and 37.3% eradication of mature biofilms, whereas rosemary-based combinations resulted in 57.1%, 69.4%, and 42.7% inhibition, respectively. These findings highlight the potential of multi-component systems integrating biogenic nanomaterials, phytochemicals, and conventional antibiotics as a promising strategy to enhance antimicrobial efficacy against persistent biofilm-forming non-aureus staphylococci.