Biofilm  formation is one of the important virulence factor  that play a major role in the bacterial pathogenicity, and are highly resistant to antimicrobial agents and host immunity. Nanoparticles are antimicrobial agent and the antimicrobial efficacy can be enhanced by coated the nanoparticles with appropriate material. This study demonstrated the antimicrobial activity of chitosan coated iron oxide nanoparticle against Gram-positive and Gram-negative bacteria. Particles of chitosan coated iron oxide were synthesized via co-precipitation method. The particles obtained had an average diameter 85 nm; the particles were used to inhibit Staphylococcus aureus and Escherichia coli biofilm on polystyrene surface. The bacteria were added in 96-well plates to incubate with chitosan-coated iron oxide nanoparticles and without  chitosan-coated iron oxide nanoparticles as control for 20 hours. The biofilm was measured using the safranin staining method. That showed variable results depending on bacterial species. However, the highest biofilm formation was recorded for S. aureus (OD= 0.33). It was seen that exposure of grown cells to chitosan coated iron oxide nanoparticle inhibiting biofilms formation for S. aureus and E. coli. A decreased in biofilm formation depends on the concentrations of nanoparticles tested and the type of bacteria. At 50 mg/ml concentration chitosan coated iron oxide nanoparticle have the highest percentage inhibition (48.2 %) p≤0.05 for S. aureus and (33.6%) p≤0.05 for E. coli . No inhibition was observed at 0.5 mg/ml in both bacterial strains. Inhibition persentage of chitosan coated iron oxide nanoparticles at 5mg/ml and 0.5mg/ml was not significant p˃0.05 compared with the control. Our result indicated that chitosan coated iron oxide nanoparticles have anti biofilm against bacteria cells and its efficacy depends on the bacterial strain.

Published 01 August 2018

DOI: 10.14500/icpas2018.mim104

http://dx.doi.org/10.14500/icpas2018.mim104