The aim of this study was to investigate the antibacterial and antibiofilm properties of low viscosity chitosan on S. epidermidis growth and biofilm formation.

Methods and Results
The antibacterial and antibiofilm properties were investigated, during both planktonic growth and biofilm formation. This was performed using different concentrations in media and by coating on polystyrene surfaces. In addition, the bactericidal effect was investigated using a modified direct contact test. The results showed that low viscosity chitosan in media had both a bacteriostatic and bactericidal effect on planktonic growth and biofilm formation of S. epidermidis in a concentration dependent manner. Polystyrene discs coated with chitosan reduced both early biofilm formation (6 h) and late biofilm formation (18 h), as confirmed by scanning electron microscopy. The modified direct contact test showed a bactericidal effect.

This study demonstrated that low viscosity chitosan has a bacteriostatic and bactericidal activity against S. epidermidis and that the activity is dependent on the amount of chitosan added. In addition, low viscosity chitosan reduced biofilm formation both when added to media and when coated on polystyrene surfaces.

Significance and Impact of Study
Low viscosity chitosan could be a contribution to new treatment approaches of biofilm-related infections of S. epidermidis.

Antibacterial and Antibiofilm Effect of Low Viscosity Chitosan against Stapylococcus epidermides
Dragland IS, Rukke HV, Stenhagen ISR, Lönn-Stensrud J, Kopperud HM
International Journal of Microbiology, Volum 2016, Article ID 9159761,