Antibacterial Effect of Silver Nanoparticles From <i>Withania coagulans</i> (Indian Rennet) Against Bacterial Pathogens of Broiler Chicken

The rise of multidrug resistance (MDR) in pathogens presents a significant challenge to global health, particularly in poultry industries. This study explores the antibacterial efficacy of silver nanoparticles (WcAgNPs) synthesized from Withania coagulans fruit extract against MDR Salmonella sp. and Escherichia coli. Phytochemical analysis of the fruit extract revealed a rich profile, including tannins, phenols, steroids, and terpenoids. Central composite design and response surface methodology (RSM) were utilized to optimize the synthesis parameters at pH 9, temperature 60°C, incubation for 24 h, wavelength 400 nm, and silver nitrate concentration of 3 mM. Characterization of WcAgNPs through FTIR, zeta sizer, SEM, EDX, and XRD confirmed their spherical shape, crystalline structure, and average size of 232.8 nm with a high silver content of 95.64%. Antibacterial tests showed significant inhibition, with zones of 26 mm against Salmonella sp. and 37 mm against E. coli. Minimum inhibitory concentrations (MIC) were 0.04 mg/µL for Salmonella sp. and 0.002 mg/µL for E. coli. These findings highlight WcAgNPs as a promising therapeutic agent for controlling poultry infections. Future research should focus on in vivo trials to confirm their safety and efficacy. Successful application of WcAgNPs could revolutionize poultry health management, providing effective alternatives to traditional antibiotics and advancing sustainable farming practices.