The retention of bacteria on hygienic surfaces presenting scratches of microbial dimensions

To produce surfaces of defined linear topographical features which reflect those found on worn and new stainless steel, to monitor the effect of feature dimensions on the retention of Listeria monocytogenes and Staphylococcus sciuri.

Surfaces were fabricated with parallel linear features of 30 microns or of microbial dimensions (1.02 and 0.59 microm width) and used in microbial retention assays with Staph. sciuri and L. monocytogenes. Retained cells were distributed uniformly across the smooth 30 micron featured surfaces but were retained in high numbers on microtopographies at the 'peaks' between the wide grooves. On smaller features, retention was attributed to the maximum area of contact between cells and substratum being attained, with cocci being embedded in 1.02-microm-width grooves, and rods aligned along (and across) the densely packed parallel 0.59-microm grooves.

The dimensions of surface features may enhance or impede cell retention. This phenomenon is also related to the size and shape of the microbial cell.

Findings may help describe and evaluate properties of hygienic and easily cleanable surfaces.