The antibacterial and antihemolytic activities assessment of zinc oxide nanoparticles synthesized using plant extracts and gamma irradiation against the uro-pathogenic multidrug resistant Proteus vulgaris.

In the case of Proteus vulgaris infection, the increased occurrence of multidrug-resistance strains has become a critical challenge in the treatment of urinary tract diseases. Therefore, using plant extracts as eco-friendly antibacterial provides an attractive solution to battle bacterial infection. The current study investigates the antibacterial and antihemolytic activity of nine medicinal plant extracts against P. vulgaris. Citrus limon extract at 150 µg/ml exhibited the highest antimicrobial action against P. vulgaris (the inhibition zone diameter; 22.7 mm). Zinc oxide nanoparticles (ZnO NPs) are synthesized using the plant extracts of C. limon, Allium sativum, Sonchus bulbosus, Allium cepa, and Asparagus racemosus. The antibacterial activity of ZnO NPs synthesized using C. limon extract at 150 µg/ml is significantly increased (33.8 mm). ZnO NPs synthesized using A. cepa, A. racemosus, and C. limon plant extracts are effectively protective for human red blood cells. The ZnO NPs synthesized using C. limon extract are characterized using UV-Visible spectroscopy, FTIR, XRD, and TEM. FTIR revealed that the plant extracts may serve as reducing and capping agents of ZnO NPs. XRD spectra confirmed the crystallinity of ZnO NPs. TEM image demonstrated the formation of spherical shapes of ZnO NPs with an average size of 37.05 nm. SEM of P. vulgaris cells treated with ZnO NPs showed cellular morphological damage compared to the untreated cells. ZnO NPs are synthesized by gamma irradiation as a clean and novel method. This study recommended the promising uses of the biosynthesized ZnO NPs using plant extracts as a natural, unique approach, to control the pathogenicity of P. vulgaris.

Biogenic synthesis of silver nanoparticles using Gliocladium deliquescens and their application as household sponge disinfectant.

The topic of this investigation was to evaluate the microbial contamination of household sponges, biosynthesize of silver nanoparticles (Ag NPs) by Gliocladium deliquescens cell-free supernatant, and estimate the efficiency of Ag NPs as an acceptable disinfectant. The 23 factorial design was applied for the optimization of Ag NPs synthesis. Silver nitrate (AgNO3) concentration was the main positive impact on Ag NP biosynthesis. Various gamma irradiation doses were used in Ag NP production where the highest yield production was at 25.0 kGy. Ag NPs were characterized by UV-Vis. spectroscopy, The Fourier-transform infrared spectroscopy analysis (FTIR), dynamic light scattering (DLS), X-ray diffraction (XRD), and transmission electron microscope (TEM). Ag NPs were monodispersed spherical-shaped with 9.68 nm mean size. Two hundred sponge samples that were collected from different Egyptian household furniture and kitchens were highly contaminated by various contaminants including Salmonella spp., Staphylococcus spp., coliform bacteria, Gram-negative bacteria, yeasts, and molds. Ag NPs showed functional antimicrobial activity against all the microbial contaminants; Salmonella spp. was completely inhibited by Ag NP (50.0 µg/mL) treatment. The Ag NPs have the maximum inhibition zone against Salmonella spp. (14 mm) compared with the Staphylococcus spp. (12.3 mm). The minimum inhibitory concentration (MIC) of Ag NPs against Salmonella spp. and Staphylococcus spp. were 6.25 µg/ mL and 12.5 µg/ mL, respectively. The antibiofilm activity of Ag NPs was the highest at the concentration of 50.0 µg/mL recording 63.3 % for Salmonella spp. and 54.5 % for Staphylococcus spp. Ag NPs may find potent disinfectant applications for household purposes.