Hydrophobic interaction--a mechanism of bacterial binding

Hydrophobic interaction or the hydrophobic effect is a chemical reaction between two or more substances or particles in an aqueous phase with elimination of the water associated with each of the particles. A gain in free energy results, since the state of separate particles surrounded by water is more energy requiring than the bound state. Low surface tension, solubility in organic solvents, hydrophobicity and attractive van der Waals interaction are often used as synonyms of hydrophobic interaction. The liability to hydrophobic interaction of bacteria and animal cells can be assessed in several ways, including contact angel measurements, engulfment at solidification fronts, critical surface tension of binding or desorption, aqueous polymer two-phase partitioning and hydrophobic interaction chromatography. In general, hydrophobic surface properties of bacteria seem to promote their association with different animal cells, comprising interactions enhanced by envelope mutations (S leads to R), immunoglobulins (IgG) or lectins (fimbriae), although the interacting structures on the bacterium and the animal counterpart are structurally distinct in each reaction.