Chitosan/silver nanocomposites enhanced the biofilm eradication in biofilm forming Gram positive S. aureus

Abstract

Biofilm is the important virulence factors in bacteria to develop multi drug resistant effect against existing bacteria word wide. The eradication of biofilm is the important research recent years due to the increased mortality rate. For this, the current research was focused on inhibition of biofilm producing bacteria S. aureus using chitosan/silver nanocomposites by various invitro experiments. The result of anti-biofilm activity was shown 26 mm zone of inhibition against gram positive S. aureus after treatment with chitosan/silver nanocomposites combination at 24 h incubation. In addition, the biofilm adherent ability in 24-well polystyrene well plate result was exhibited 96 % biofilm degradation and viewed by after crystal violet stain wash. Importantly, biofilm survival rate was decreased to 97 % at 400 µg/mL concentrations, and it confirmed by liquid maintenance method. Furthermore, the complete exopolysaccharide damages were observed at 400 µg/mL concentrations, and confirmed by congo red agar assay. In congo red agar plate, the black color was absent in the biofilm forming S. aureus after 24 h incubation. It conveyed that the synthesized Chitosan/silver nanocomposites was very efficient nanomaterial to eradicate the biofilm formation in gram positive bacteria at concentration dependent manner.

Keywords

• Chitosan
• Silver nanoaprticles
• Nanocomposites
• Biofilm inhibition assay
• Metabolic survival effect
• Exopolysachharide damage