The same conclusions were obtained in another study concerning the ability of adhesion of a culture
collection strain (Listeria monocytogenes ATCC 15313) to the materials mentioned above [48].
Another interesting point has to do with the behaviour of the two silestones, in fact the lower extent of
adhesion was detected on the two polymers being slightly high on the two silestones. Thus, it seems that
the incorporation of Microban is not totally effective against the adhesion of these pathogenic bacteria.
On the other hand, this raised the question that adhered cells, especially to silestone, might not be viable.
However, cell viability assays, which allow to assess bacterial membrane integrity with the LIVE/DEAD
Backlight kit (Molecular Probes, Eugene, OR, USA) [49], revealed that the lowest percentage of L.
monocytogenes survival was found on white silestone (18.5 % cells with intact membrane) while,
curiously, in silestone beige the percentage of viable cells was very high (74.0 % cells with intact
membrane).