Bacterial Adhesion and Biofilm Formation in the Presence of Chitosan and Its Derivatives

Abstract

The effect of chitosan and its derivatives on adhesion and biofilm formation by bacteria with diametrically opposite properties of cell surfaces was studied. Treatment of polystyrene surface with chitosan or its quaternized derivatives was shown to decrease its hydrophobicity significantly, resulting with an over fourfold inhibition of M. smegmatis adhesion. On the contrary, E. coli with hydrophilic cell surface showed higher affinity to the polystyrene surface in the presence of chitosan. The possibility of inhibiting formation of M. smegmatis biofilms by chitosan, which increases its antimycobacterial properties after its quaternization, has not been demonstrated previously. At the same time, the increase in the hydrophobicity of quaternized chitosan resulted in its decreased efficiency against E. coli cells with a relatively hydrophilic surface. The succinylated form of chitosan with negatively charged sites in the structure had practically no antibacterial properties due its decreased ability to bind with the target cells.