In a similar study to the above mentioned for L. monocytogenes, we studied the adhesion ability of
four Salmonella Enteritidis isolates (two isolated from poultry- one from the water of packaged chicken,
and other from chicken breast; the other two were human isolate outbreak strains) to three different
materials used in kitchens (polyethylene, polypropylene, and granite) it was concluded that, similarly to
Listeria monocytogenes, the different extents of adhesion could not be explained in terms of surface
hydrophobicity or roughness of the materials tested [53]. In fact, the main conclusion that was drawn is
that Salmonella adhesion is strongly strain dependent, despite the similar degree of hydrophobicity
displayed by all the strains assayed, and this can constitute a factor of virulence among the different
serotypes. This strain variability was confirmed in another study where the adhesion ability of the same
isolates was tested on stainless steel 304 [54]. Actually, the extent of adhesion to stainless steel ranged
from 2.x104 cells/mm2 for S. Enteritidis isolated from chicken breast to 4.67x103 cells/mm2 for S.
Enteritidis isolated from the water of packaged chicken. Essentially, no change in hydrophobicity or in
roughness can be responsible for such variability because the adhesion substratum was the same (SS
304) for all strains assayed