Research in the field of bioadhesion is crucial, especially the state of primary adhesion due to the fact that firstly adsorbed bacteria on a surface are the link between on top growing bacteria and the surface. Finally, these bacteria are the carrier of biofilm and consequently microbial affection. In case of sensitive sectors such as food industry or biomedicine and the great environmental problem with triclosane for instance, the use of biocides should be prevented. Non-toxic alternatives like antiadhesive structures can be added on surfaces to inhibit bacterial adhesion and spreading. If using polymeric surfaces, modifications can be put into practice by glow discharge plasma with low pressure and non-thermal behaviour. Experiments include cultivations with E. coli JM109 to reach the primary adhesion state in order to enable adhesion force measurements between bacterium and surface with a new micromanipulation system installed in REM. To alter the surface, hydrophobic surfaces were generated with Argon/C4F8 plasma. It revealed that E. coli primarily adhere within 6 h in a bioreactor circulating around specimens. Morphologically characteristics such as single existing cells, no forming of microcolonies and direct contact to the surface define the term of primary adhesion. The bacterial adhesion force for untreated PC is 101,8 ± 24,8 µN (n =10) and for plasma fluorinated PC 12,9 ± 6,1 µN (n=9) respectively. These findings demonstrate the successful validation of the new micromanipulation system to measure the bacterial adhesion force and additionally show the antiadhesive effect of fluorine.
Results of the master thesis by Nathalie Stefani, University of Applied Sciences Ansbach