Background and Aim : Background:
Biofilm is a complex structure of microbiome having different bacterial colonies or a single type of cells in a group; adhere to the surface. These cells are embedded in extracellular polymeric substances, a matrix which is generally composed of eDNA, proteins and polysaccharides, showed high resistance to antibiotics. The ability of bacteria in biofilm production such as Pseudomonas aeruginosa and
Acinetobacter baumannii as the two most prevalent nosocomial infections increase the antibiotic resistance. There are many approaches being used to control infections by suppressing their formation. Nanoparticles (NPs), a Nano-sized, safe, and highly cost-effective antibacterial agent are potential biomedical tools. Methods : Methods: In this study, we evaluated the antibacterial and anti-biofilm activity of AgNPs on resistant isolates of two introduced bacteria isolated from burn patients. To determination the active concentration of particles on reducing biofilm production was performed by MIC, while the MBC activity of AgNPs were evaluated either on both studied bacteria. Quantity and activity of bacteria in biofilm formation was performed by Microtiter Dish
Biofilm Formation Assay using an ELISA auto reader (OD=570). Results : Results: In this study, AgNPs exhibited strong antibacterial and anti-biofilm properties on multi-drug resistant P.aeruginosa and A.baumannii isolates. AgNPs exhibited minimum inhibitory concentrations of 128 and 256 μg/ml, against P.aeruginosa and A.baumannii, respectively and this is while the respective minimum bactericidal concentrations were 256 and 562 μg/ml. The significant inhibition in biofilm formation was observed at ≥64 μg/ml for the AgNPs. Conclusion : Conclusion: This study provides evidence that AgNPs possess high antibacterial and anti-biofilm activities.
Biofilm inhibition at sub-MIC concentrations might be due to non-lethal damage or due to inhibitory effect on expression of genes related to motility and biofilm formation. This suggests that AgNPs might be used in more low concentration as a potential anti-virulent agent in the control of burn patients’ infections.