Prevalence of L., Listeria monocytogenes, Esherichia coli O157:H7 and Esherichia coli O104:H4 in mixed letture and rocket leaves sold in Apulian markets.

Minimally processed vegetables of different brands, were purchased from different supermarkets located in Puglia, Italy. Analyzed samples contained mixed ingredients such as lettuce, carrots, endive, radicchio, red chicory and valerian or single ingredients such us icerberg lettuce or rocket leaves. All samples were purchased before their best-before date, transported under refrigeration conditions to the laboratory and immediately analyzed. The occurence of Listeria spp., Listeria monocytogenes, Esherichia coli O157:H7 and Esherichia coli O104:H4, was tested using both selective media, immunoassay tests and PCR detection tools. Furthermore, a DNA protocol suitable to extract DNA from artificial inoculated vegetables samples was developed.