Occurence of L. monocytogenes in fresh fruits and vegetables from organic farms in west pomeranian region [Wystepowanie l. monocytogenes w świezych owocach i warzywach pochodzacych z upraw ekologicznych województwa zachodniopomorskiego]
Szymczak B.,Katedra Mikrobiologii i Biotechnologii Stosowanej |
Sawicki W.,Katedra Mikrobiologii i Biotechnologii Stosowanej |
Boguslawskawas E.,Katedra Mikrobiologii i Biotechnologii Stosowanej |
Koronkiewicz A.,Katedra Mikrobiologii i Biotechnologii Stosowanej |
Dabrowski W.,Katedra Mikrobiologii i Biotechnologii Stosowanej
Zywnosc. Nauka. Technologia. Jakosc/Food. Science Technology. Quality | Year: 2011
Pursuant to the Commission Directive (EC) No. 1441/2007 of 05.12.2007 on microbiological criteria for foodstuffs, there is no obligation to inspect fresh fruits and vegetables whether or not they contain L. monocytogenes although there are more and more reports on finding these bacteria in plant materials. The quality of fruits and vegetables in Poland is assessed based on the visual evaluation of freshness and external appearance of the material, and on checking if this material does not get mouldy. The objective of this paper was to assess the occurrence of L. monocytogenes in fresh fruits and vegetables and to compare different methods of identifying these bacteria. 220 samples were analyzed (80 fruits and 140 vegetables); all of them originated from both the local retail outlets and the agricultural farms using manure as a fertilizer. Based on the identification performed according to PN EN ISO 11290-2:2000, Listeria sp was found in 50 % of beetroot samples, in 25 % of carrot, in 15 % of tomatoes and potatoes, and in 5% of parsley and in 25 % of strawberries. And when using a multiplex PCR technique, L. monocytogenes was found in 10 % of the strawberry samples, in 5 % parsley, and in 15 % potatoes. Biochemical analyses should not be the final phase of identifying L. monocytogenes because there are wide discrepancies between the results of this analysis and the results of research conducted using the molecular biology methods. A correlation was shown between the presence of L. monocytogenes in fruits and vegetables and the type of fertilizer used. Listeria sp and L. monocytogenes were isolated only from the samples of fruits and vegetables grown in farms where soils were manured. Owing to the frequency of L. monocytogenes occurrence in fruits and vegetables from certified farms running organic farming, it is vital to revise the control screening of plant materials and to make it obligatory.