The assessment of antibiofilm activity of chitosan-zinc oxide-gentamicin nanocomposite on Pseudomonas aeruginosa and Staphylococcus aureus.

In the present study, chitosan-zinc oxide (CS-ZnO) nanocomposite with/without gentamicin was synthesized and characterized which used as an antibiofilm agent to inhibit the biofilm formation of Pseudomonas aeruginosa (P. aeruginosa) PAO1 and Staphylococcus aureus (S. aureus). Synthesized CS-ZnO nanocomposite was characterized with the DLS (Dynamic Light Scattering), FTIR (Fourier Transform Infrared), XRD (X-ray Diffraction) and SEM (Scanning Electron Microscope). The minimum inhibitory concentrations (MICs) against P. aeruginosa PAO1 and S. aureus determined using broth microdilution methods. The influence of sub-MIC (1/4 MIC) and MIC concentration of CS-ZnO nanocomposite and gentamicin alone and in combination on biofilm formation was also determined. A four-fold MIC reduction in S. aureus and P. aeruginosa PAO1 treated by the gentamicin loaded CS-ZnO nanocomposite, and 84% reduction of biofilm formation for P. aeruginosa PAO1 and 77% reduction of biofilm formation for S. aureus, was observed compared to the gentamicin alone (P < 0.05). This study showed the important role of nanocomposite in designing novel antibacterial and antibiofilm agents to combat the P. aeruginosa and S. aureus biofilm-related infections.