Available surface dictates microbial adhesion capacity

The bacterial adhesion can be controlled (inhibit or promote) by different material surface characteristics like surface roughness, on which we concentrate in our study. Four different glass surfaces were prepared by polishing the glass plates with different gradations. The corresponding surface roughness was controlled by atomic force microscope and profilometer. For experiments we have used one Gram-positive bacterium (Staphylococcus aureus) and two Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli). The rate of adhered bacteria on glass surfaces was determined spectrophotometrically. The results showed that the rate of adhered bacteria increases with increasing surface roughness. The increased adhesion of bacteria on more rough surfaces is the interplay between the increasing effective surface and increasing number of defects on the surface. In order to keep all parameters under control we have also measured the surface charge density and hydrophobicity of bacteria and glass surfaces as well.