Effect of polymer surface properties on the reversibility of attachment of Pseudomonas aeruginosa in the early stages of biofilm development

Biofilm fouling is a common problem in industrial water and medical systems. Prevention of biofilm. formation is often difficult because of the numerous potential attachment and adhesion mechanisms of bacteria, and therefore removal strategies are often necessary. Three surface properties, surface roughness, hydrophobicity (contact angle), and surface charge (zeta potential) were measured for several polymeric surfaces and related to specific biofilm characteristics. Biofilms of Pseudomonas aeruginosa were allowed to form on these surfaces for a period of 1 - 3 d, and the fraction of bacterial cells removed from each surface by exposure of biofilms to a standard shear stress was determined. Cells were most readily removed from the smoothest, most hydrophilic, neutral surfaces, with removal becoming more difficult at longer attachment times. This finding correlates directly with the finding that surfaces with these characteristics are most resistant to biofilm initiation. Therefore, it is demonstrated that by optimizing surface properties, it is possible to produce a surface from which bacteria can be more readily removed.