Bacterial strains isolated from different niches can exhibit different patterns of adhesion to substrata

Abstract

Various mechanisms have been demonstrated to be operative in bacterial adhesion to surfaces, but whether bacterial adhesion to surfaces can ever be captured in one generally valid mechanism is open to question. Although many papers in the literature make an attempt to generalize their conclusions, the majority of studies of bacterial adhesion comprise only two or fewer strains. Here we demonstrate that three strains isolated from a medical environment have a decreasing affinity for substrata with increasing surface free energy, whereas three strains from a marine environment have an increasing affinity for substrata with increasing surface free energy. Furthermore, adhesion of the marine strains related positively with substratum elasticity, but such a relation was absent in the strains from the medical environment. This study makes it clear that strains isolated from a given niche, whether medical or marine, utilize different mechanisms in adherence, which hampers the development of a generalized theory for bacterial adhesion to surfaces.

FIG. 1.

Average initial deposition rates (j₀) of three marine and three medical strains to different polyurethane coatings and glass in the parallel plate flow chamber (PP) (closed symbols) and stagnation point flow chamber (SP) (open symbols) as a function of surface free energy γ (a) and elasticity modulus (b). Solid lines indicate the results with the best fit, whereas dashed lines indicate the results obtained from similar experiments with marine strains (2).