Oxidative stress, DNA, and membranes targets as modes of antibacterial and antibiofilm activity of facile synthesized biocompatible keratin-copper nanoparticles against multidrug resistant uro-pathogens

Escherichia coli and Enterococcus faecalis are two of the most prevalent uro-pathogens and are difficult to treat as they acquire multidrug-resistant traits. In this study, the main objective was to develop biocompatible copper nanoparticles using chicken feather keratin protein (CuNPs-K) and to investigate their impact on multidrug-resistant (MDR) uro-pathogens, E. coli and E. faecalis, under both single and mixed culture conditions. CuNPs-K were characterised by UV-Vis spectroscopy, dynamic light scattering, X-ray diffraction, Fourier transform infrared spectroscopy, and docking experiments. The MIC values of CuNPs-K against single and mixed planktonic cultures were 50 mu g/ml and 75 mu g/ml, respectively. CuNPs-K efficiently disrupted the biofilm of single and mixed uro-pathogen cultures by eliminating sessile cells. This biofilm disruption may be attributed to a decline in the production of extracellular polymeric substances in both single and mixed bacterial cultures treated with CuNPs-K. Moreover, selective antimicrobial activity was determined by selectivity assays using T24 cells. CuNPs-K targets both the bacterial membrane and DNA with elevated reactive oxygen species (ROS) as their bactericidal mode of action. This comprehensive antimicrobial activity of CuNPs-K was further confirmed in vivo by using the zebra fish model. In this study, CuNPs-K effectively reduced bacterial load with increased survivability of infected zebrafish. All these results suggest that CuNPs-K can be explored as an exceptional antibacterial agent against MDR uro-pathogenic E. coli and E. faecalis. [GRAPHICS] .

Automated summary

This study developed CuNPs-K using chicken feather keratin protein and investigated their impact on multidrug-resistant uro-pathogens E. coli and E. faecalis. CuNPs-K efficiently disrupted the biofilm and exhibited selective antimicrobial activity. It targeted bacterial membrane and DNA with elevated reactive oxygen species as their bactericidal mode of action.