Exploring Listeria monocytogenes in Ewe Milk: ssrA Gene-based Real-time PCR Identification, Phylogenetic Analysis, and Antibacterial Assessment of Magnesium Oxide Nanoparticles Synthesized with Myrtus communis Leaf Extract

Evaluation of a microbiological indicator test for antibiotic detection in ewe and goat milk

Microbiological Quality of Raw Goat's and Ewe's Bulk-Tank Milk in Switzerland

Biofilms formed in food-processing environments are of special importance as they have the potential to act as a persistent source of microbial contamination that may lead to food spoilage or transmission of diseases. The creation of microbial biofilms, which can be a source of food product contamination with food spoilage and foodborne pathogenic bacteria, is one of the most critical elements in the food industry. The goal of this study was to see how well magnesium oxide (MgO) and copper oxide (CuO) nanoparticles (NPs) inhibited growth and biofilm formation of two common foodborne bacterial pathogens. This study was completed in the year 2020. Resazurin reduction and micro-dilution procedures were used to assess the minimum inhibitory concentration (MIC) of magnesium oxide and copper oxide nanoparticles for Escherichia coli O157: H7 (ATCC 35 218) and Listeria monocytogenes (L. monocytogenes) (ATCC 19 118). The bacterial adhesion to hydrocarbon technique was used to determine the cell-surface hydrophobicity of the selected bacteria. The surface assay was also used to calculate the influence of the NPs coated surfaces on the biofilm formation of the selected bacteria. Magnesium oxide nanoparticles had MICs of 2 and 2 mg ml−1, while copper oxide nanoparticles had MICs of 0.16 and 1 mg ml−1 against E. coli and L. monocytogenes, respectively. At the MIC, the magnesium and copper nanoparticles inhibited biofilm formation of E. coli and L. monocytogenes by 89.9 and 96.6 percent and 93.6 and 98.7 percent, respectively. The hydrophobicity of E. coli and L. monocytogenes was determined to be 74% and 67%, respectively. The surface assay revealed a substantial reduction in bacterial adhesion and colonization on NPs-coated surfaces. Both compounds had inhibitory effects on E. coli and L. monocytogenes, according to our findings. Even at sub-MICs, NPs were found to be able to prevent biofilm development. The microbial count and production of microbial biofilms were reduced on surfaces coated with MgO and CuO nanoparticles. MgO and CuO nanoparticles can be utilized as a cleaning agent for surfaces to avoid the formation of foodborne bacterial biofilms, which is important for public health.

Biocidal chitosan-magnesium oxide nanoparticles via a green precipitation process

Enumeration and Confirmation of Aeromonas hydrophila, Aeromonas caviae, and Aeromonas sobria Isolated from Raw Milk and Other Milk Products in Northern Greece

Epilepsy is a neurological disorder involving persistent spontaneous seizures and uncontrolled neuronal excitability that leads to cognitive impairments and blood–brain barrier (BBB) disruption. Currently available antiepileptic drugs present side effects and researchers are trying to discover new agents with properties to overcome these drawbacks. The aim was to synthesize magnesium oxide (MgO) and zinc oxide (ZnO) nanoparticles from Datura alba fresh leaf extracts and evaluate their anti-epileptic potential in mice kindling or a repetitive seizures model. The phytoassisted synthesized nanoparticles were characterized using spectroscopy; FT-IR, XRD, SEM, and EDX. Analysis of the NPs confirmed the crystalline pleomorphic shape using the salts of both zinc and magnesium possibly stabilized, functionalized and reduced by bioactive molecules present in plant extract. By using several characterization techniques, NPs were confirmed. UV-Vis spectroscopy of biologically produced ZnO and MgO revealed distinctive peaks at 380 nm and 242 nm, respectively. Our findings categorically demonstrated the reductive role of biomolecules in the formation of ZnO and MgO NPs. The mice kindling model was induced using seven injections of Pentylenetetrazole (PTZ, 40 mg/kg, i.p) for 15 days alternatively. The results showed that mice post-treated with either ZnO or MgO nanoparticles (10 mg/kg, i.p) significantly improved in respect of behavior and memory as confirmed in the Morris water maze (MWM), open field (OF), novel object recognition (NOR) test compared with PTZ treated mice. Furthermore, the ZnO and MgO nanoparticle treatment also maintained the integrity of the BBB, reducing the leakage, as confirmed by Evans blue dye (EBD) compared with PTZ treated mice only. In summary, the current finding demonstrates that green synthesized ZnO and MgO nanoparticles have neuroprotective, ant-epileptic potential, molecular mechanisms, and clinical implications need to be further explored.

Survival of Listeria monocytogenes in Frozen Ewe's Milk and Feta Cheese Curd

Concentration-dependent behaviors of bone marrow derived mesenchymal stem cells and infectious bacteria toward magnesium oxide nanoparticles

Enhanced photocatalytic activity of methylene blue dye by DIFS synthesized pure and Mn doped MgO nanostructures

Background: The spread of pathogenic microorganisms in food and beverage and their resistance to antibiotics have raised major concerns for public health. The aim of this study was to investigate the antimicrobial activity of various metal oxide nanoparticles (NPs) including zinc oxide (ZnO), magnesium oxide (MgO), and iron oxide (Fe2O3) NPs against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Furthermore, the antimicrobial activity of these NPs in milk was studied along with mild heat. Methods: In this experimental study, the antibacterial activity of ZnO, MgO, and Fe2O3 NPs were initially evaluated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) methods. Later, the antimicrobial effect of these NPs was investigated in milk along with mild heating. To determine the morphological changes in S. aureus and E. coli, electron microscopy scanning was applied before and after the antimicrobial treatments. Results: The MBC and MIC values presented by Fe2O3, ZnO, and MgO NPs against pathogenic bacteria showed that MgO NPs were the most potent substances for inhibiting the growth of S. aureus and E. coli. The results also indicated that use of these NPs had synergistic effects in combination with the heating treatment. Electron microscopy scanning also revealed that treatment with MgO NPs could distort and impair the cell wall of the pathogenic bacteria, leading to the leakage of intracellular components and bacterial death. Conclusion: The results suggest that MgO, ZnO, and Fe2O3 NPs can be applied for industrial food processing as effective antimicrobial compounds to decrease the temperature required for pasteurizing milk.

The use of nanoparticles (NPs) has been extended to many fields such as agriculture, food industry, medicine and biotechnological fields. Thereby, human exposure to NPs consequently increases. Therefore, there is a concern about the potential biological effects and toxicity of NPs for humans and the environment. This study aimed to investigate the cytotoxicity effects of magnesium oxide (MgO) and silica (SiO2) NPs on human colon adenocarcinoma (HT-29) after 24 hours of exposure. In this study, cytotoxicity of MgO and SiO2 NPs was evaluated using MTT assay after 24 hours of MgO (50 nm) and SiO2 (90-110 nm) NPs exposure at doses of 25-200 µg/ml. Moreover, to assess the rate of cell apoptosis, cells were stained with ethidium bromide/acridine orange stain. The staining was examined under a fluorescent microscope. The exposure of HT29 cells to SiO2 and MgO NPs increased cytotoxicity in a dose-dependent manner. Also, these results showed a significant increase in apoptosis induction in treated groups with MgO and SiO2 NPs. These results showed that SiO2 and MgO NPs can cause cytotoxicity in HT29 cells and it is better to avoid using them in food stuff and food packaging ingredients.

Effect of pH on the microstructure and antibacterial properties of MgO nanoparticles by microwave-assisted solution combustion

Magnesium oxide (MgO) nanoparticles are commonly used to enhance the reactivity and performance of devices and systems in various applications, primarily due to the heat-resistance, binding, and alkaline properties of MgO. However, most of the methods used to synthesize MgO nanoparticles suffer from nonuniform particle size distributions that make it difficult to manufacture stable particles. In this study, uniform magnesium oxide (MgO) nanoparticles were developed for TiO2 photoelectrodes of dye-sensitized solar cells (DSSCs) to enhance their interfacial resistances. The uniform MgO nanoparticles were synthesized from MgO 93% using a poly(acrylic acid) template-assisted method. The particle size and crystalline structure of MgO nanoparticles were characterized by NANOPHOX particle size analysis, transmission electron microscopy, and X-ray diffraction. Multilayered TiO2 photoelectrodes containing interlayers of MgO nanoparticles were fabricated as photoelectrodes for DSSC devices, and their photovoltaic performances were investigated. When the MgO interlayer was introduced into the multilayered TiO2 photoelectrode, it not only increased the photocurrent value of the DSSC device but also improved its power conversion efficiency. The DSSC device containing the MgO interlayer and the scattering layer exhibited an open-circuit voltage of 0.74 V, a short-circuit current density of 14.60 mA/cm2, and a fill factor of 0.64 under a photointensity of 100 mW/cm2 at AM 1.5, resulting in an overall solar energy conversion efficiency of 6.94%. The application of an MgO interlayer in a DSSC device exhibited improved conductivity, charge transfer ability, and excellent device performance.

This study focuses on the synthesis and characterization of magnesium oxide (MgO) nanoparticles prepared via the sol–gel method. The structural, functional, and optical properties of the synthesized MgO nanoparticles were analyzed using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and ultraviolet–visible (UV–Vis) spectroscopy techniques. XRD analysis confirmed the formation of well-defined crystalline MgO nanoparticles with uniform crystallite size. FTIR spectra exhibited characteristic peaks corresponding to the asymmetric and symmetric stretching vibrations of Mg–O bonds, confirming the successful formation of MgO. The UV–Vis spectrum revealed a broad and prominent excitonic absorption band in the range of 260–300 nm, indicating the nanoscale nature of the particles. The optical band gap of the synthesized MgO nanoparticles was estimated to be 3.14 eV, consistent with the semiconductor behaviour of nanosized MgO. The prepared MgO nanofluids were evaluated for their thermophysical properties. The viscosity of the MgO–deionized water nanofluids was measured using an Ostwald viscometer, while the thermal conductivity was estimated based on the Maxwell model. The stability of the nanofluids was assessed through zeta potential analysis. The results demonstrate that MgO nanoparticles synthesized via the sol–gel route possess high crystallinity, excellent stability, and predominantly nano spherical morphology, making them suitable for heat transfer and fluid dynamic applications. Keywords: MgO nanoparticles, sol-gel method, XRD, FTIR, UV-vis, thermal conductivity.

Detection, Occurrence, and Characterization of Escherichia coli O157:H7 from Raw Ewe's Milk in Spain