Impact of Zinc Oxide Nanoparticles in growth and virulence of some foodborne bacteria

Abstract

ABSTRACT The antibacterial activities of synthesized and commercial zinc oxide nanoparticles (ZnO NPs) were analyzed to ensure their effectiveness as food preservative against S. Typhimurium, S. aureus and E. coli. ZnO NPs were synthesized by a wet chemical method, identified and characterized by UVvisible spectrophotometer, Transmission electron microscope (TEM) and (XRD)

for

confirmation synthesis. The antibacterial activities of synthesized and commercial ZnO NPs were analyzed. Synthesized ZnO NPs showed inhibition for S. aureus, E. coli and S. Typhimurium with MIC 0.3 mg/ml, 0.6 mg/ml and 1.25 mg/ml respectively. while the MIC of commercial ZnO nanomaterial was found to be 0.15 mg/mL for S. aureus and 0.3 mg/mL for E. coli and S. Typhimurium. Using RT-PCR, the gene expression of gamma hemolysin (hlg) and aggregation genes (csgD) in media treated with subMIC concentration ZnO NPS were reduced. The present in vivo study was aimed to investigate the oral toxicity of ZnO NPs, Sprague Dawley rats were administered with 50, 200, 300 mg/kg body weight (b.w) of nanosized zinc oxide suspended in distilled water through oral gavage. The effects of ZnO NPs on some immunological parameters were analyzed on day 30 of administration. The organs were collected for histopathology. Interestingly, dose-dependent decrease in serum total protein and serum albumin. Also significant leukocytosis (P ≤ 0.05), a significant increase in neutrophil, and monocyte and a decrease in lymphocyte which are dose- dependent. The incidences of microscopic lesions in liver and kidney were higher in higher doses of ZnO NPs compared to the lower dose and control group.