Abstract

Background and Aim: The development of zinc-based antimicrobials has progressed from conventional to nanoparticle (NP) formulations due to their enhanced biological properties. This study evaluates the antibacterial efficacy of green-synthesized zinc oxide NPs (ZnO-NPs) derived from Garcinia mangostana leaf extract against both pathogenic and non-pathogenic bacteria relevant to poultry health.

Materials and Methods: Using a completely randomized design, six treatment groups were tested: Positive control (PC) (tetracycline, 2.5 mg/mL), negative control (NC) (HCl 0.1 N + distilled water), and ZnO-NPs at concentrations of 2.5, 5, 7.5, and 10 mg/mL. The antimicrobial activity was assessed using the agar well diffusion method, measuring inhibition zones against Escherichia coli, S. Typhimurium, Staphylococcus aureus, and Lactobacillus plantarum.

Results: The positive control demonstrated the most significant inhibition zones across all bacterial strains. ZnO-NPs exhibited dose-dependent antibacterial activity, with maximum inhibition zones recorded as 18.58 mm for E. coli, 17.09 mm for S. Typhimurium, and 17.41 mm for S. aureus at the highest concentration (10 mg/mL). However, the antibacterial activity against L. plantarum was less pronounced, with a maximum inhibition zone of 9.93 mm. These findings indicate selective toxicity of ZnO-NPs, favoring pathogenic over non-pathogenic strains.

Conclusion: Green-synthesized ZnO-NPs using G. mangostana leaf extract demonstrate promising antibacterial properties against poultry pathogens. Their selective action highlights potential applications as eco-friendly feed additives to improve poultry health and mitigate pathogenic risks.

Keywords: antibacterial, green synthesis, nanotechnology, poultry health, zinc oxide nanoparticles.