Discrimination between random and non-random processes in early bacterial colonization on biomaterial surfaces: application of point pattern analysis

<div><p>The dynamics of adhesion and growth of bacterial cells on biomaterial surfaces play an important role in the formation of biofilms. The surface properties of biomaterials have a major impact on cell adhesion processes, eg the random/non-cooperative adhesion of bacteria. In the present study, the spatial arrangement of <i>Escherichia coli</i> on different biomaterials is investigated in a time series during the first hours after exposure. The micrographs are analyzed <i>via</i> an image processing routine and the resulting point patterns are evaluated using second order statistics. Two main adhesion mechanisms can be identified: random adhesion and non-random processes. Comparison with an appropriate null-model quantifies the transition between the two processes with statistical significance. The fastest transition to non-random processes was found to occur after adhesion on PTFE for 2–3 h. Additionally, determination of cell and cluster parameters <i>via</i> image processing gives insight into surface influenced differences in bacterial micro-colony formation.</p>