Comparative evaluation of florfenicol and polymeric nanopar-ticles loaded with florfenicol against bacterial strains isolated from chickens: insights into antimicrobial resistance

Antimicrobial resistance (AMR) poses a significant threat to both human and animal health, necessitating the search for alternative antimicrobial agents and strategies. In this study, we aimed to identify and isolate clinical bacterial strains from chickens and evaluate their sensitivity to florfenicol, a common antimicrobial agent that is used exclusively in veterinary medicine, along with polymeric nanoparticles loaded with florfenicol at various concentrations. Three clinical bacterial strains were successfully isolated and identified from chicken presenting clinical signs. In order to assess their susceptibility, the isolated strains were subjected to a standard disc diffusion assay using florfenicol. Subsequently, polymeric nanoparticles loaded with florfenicol were tested at six different concentrations and compared their efficacy against the bacterial strains. Our results demonstrated that all three clinical bacterial strains exhibited varying degrees of resistance to florfenicol. Interestingly, the use of polymeric nanoparticles loaded with florfenicol did not display enhanced antimicrobial activity compared to the free drug. Notably, the efficacy of the loaded nanoparticles did not significantly vary with different concentrations of active substance. This study highlights the importance of exploring novel therapeutic approaches to combat antimicrobial resistance. The use of polymeric nanoparticles loaded with florfenicol presents a promising avenue for overcoming resistance mechanisms and improving the efficacy of antimicrobial treatments both in human and veterinary medicine. Further investigations are needed to elucidate the underlying mechanisms and optimize the formulation of polymer nanoparticles for enhanced therapeutic outcomes in combating AMR.