Cytotoxicity of zinc oxide nanoparticles to lymphocytes using Enterococcus faecium bacteriocin and assessment of their antibacterial effects

Objective(s): Multidrug-resistant Enterococcus faecium can grow in a variety of settings and cause infections that can be fatal, making it a serious threat. Partially purified and characterized bacteriocins with antimicrobial efficacy demonstrated antimicrobial activity against gram-negative bacteria.  Methods: Zinc oxide nanoparticle (ZnO-NPs )were synthesized by a biological method from suspensions of E. faecium bacteria isolated from the Gums of healthy people at different time points (24 and 48 hour), and temperatures ranging from (35-37)°C to pH (5 - 5.30).  Results: The size of ZnO-NP particles has been determined. The biosynthesized ZnO-NPs’ peak of absorption was visible in the UV-VIS spectrum at 267 nm. The mean dimension of the biosynthesized ZnO-NPs was determined by atomic force microscopy (AFM) to be within 259.2 nm. Three different peak shapes in the XRD spectra demonstrated the production of ZnO NPs.Analysis using X-ray (EDX) demonstrates the zinc content of the ZnO-NPs. SEM was utilized to evaluate dimensions and form. The vast majority of the particles were spherical and uniform in shape, based on SEM images. The minimum inhibitory concentration (MIC) was determined at concentrations ranging between 1000,500, 250,125,64 μg/ml. The minimum inhibitory concentration for ZnO-NPs prepared from E. faecium using the microtiter plate method was 250 μg/mL. The toxicity of zinc oxide nanoparticles was tested on human lymphocytes.  Conclusions: ZnO-NPs were synthesized successfully using an easy-to-use, low-cost, green, high-throughput, and environmentally friendly technology that showed remarkable antibacterial effectiveness against a variety of bacterial species.