Effect of micro-patterning on bacterial adhesion on polyethylene terephthalate surface

Bacterial adhesion on surfaces commonly used in medicine and food industry could lead to infections and illnesses. Topographically patterned surfaces recently have shown to be a promising alternative to chemical antibacterial methods, which might release cytotoxin and promote antibiotic resistance. In this study, we fabricated micro-patterned polyethylene terephthalate surfaces, and quantitatively explored the amount and localization of Escherichia coli MG1655 cells attached on a series of defined topographies. The adhesion was conducted in static conditions and under a weak flow, in both physiological buffer and nutritious solutions. The results showed that in the presence of weak shear force, live bacteria could still maintain sensing ability in nutritious culture, but not in buffer solution. The finely textured surface, which could inhibit bacterial adhesion in the early stage of attachment, reversed its effect to enhance the adhesion after 24h incubation, indicating that microbial cells seemed to be able to sense the disadvantageous condition and eventually overcome it. In terms of adhesion localization, bacteria exhibited preferential adhesion onto the edges of topographic features. The patterned substrates that have the most even (homogeneous) bacterial localization on topographic features retained the least attachment after 24h exposure.