Abstract
Dairy udder and milk equally remain susceptible to bacterial contamination posing significant threat to food safety and security. Adding to this is overlooking some of bacterial pathogens e.g. K. pneumoniae and S. agalactiae for their infection, drug resistance, and demand of alternative therapeutics. Keeping in view the scenario, current study was planned to assess response of K. pneumoniae and S. agalactiae against wider range of antibiotics, and resistance modulation through metallic oxide nanoparticles of iron, zinc, and magnesium. Nanoparticles were prepared and characterized as per set protocols. In-vitro disc diffusion test for antibiotics, well diffusion for nanoparticles' antibacterial activity, and finally finding minimum inhibitory concentration expressing antibacterial activity was carried out. Parametric and nonparametric statistics was applied to confer outcomes using SPSS version 22 of statistical software at 5% probability. Study found 6 out of 16 antibiotics showing minor variation in means of ZOI against K. pneumoniae and S. agalactiae indicating limited scope of antibiotics to cover infection against these bacteria. When these bacteria were tested against MgO, ZnO, and Fe2O3 nanoparticles, significant antibacterial activity was noted. Fe2O3 showed significant higher antibacterial activity as compared to others against both of bacterial strains. Minimum time for maximum activity was found variable for each of nanoparticles against K. pneumoniae and S. agalactiae with a range of 8th-20th hour of incubation as significant response compared to 4th hour of incubation. Study thus concluded, narrow window of antibiotic susceptibility against K. pneumoniae and S. agalactiae while wider scope of metallic oxide nanoparticles as antibacterial alternatives.