ToF-SIMS imaging of surface self-organized fractal patterns of bacteria

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) imaging has been shown to be a useful tool to study cell adhesion onto a surface. The purpose of this work was that of investigating by means of ToF-SIMS imaging the influence of different salt environments on the adhesion and self organization of Staphylococcus epidermidis ATCC 12228 onto a nonleaching surface (native silicon oxide). Chemical maps show that the different media influence the distribution of bacteria and that their different surface organization in different media is accompanied by characteristic distributions of alkali ions and organic fragments related to the bacteria. This could help in understanding the mechanisms involved in self organization of bacteria, that are thought to be related with the ability of bacteria to modify, by means of ionic fluxes through the cell membrane, the electrostatic interactions that, in turn, appear to rule their self organization in fractal patterns. Copyright (C) 2010 John Wiley & Sons, Ltd.