2.5. Statistical analysis
The frequency of isolation of Listeria spp. and L. monocytogenes,
the number of isolates confirmed and not confirmed as Listeria spp.,
and the distribution of Listeria spp. recovered on MOX and PCOM
were compared with a Chi-square test for each food category. Data
analysis was performed with Statgraphics Centurion XV ver.15.2.06
(Statpoint Technologies, Inc., Warrenton, USA).