The aim of this study was to characterise the L. monocytogenes isolates originating from humans and foodstuffs using selected typing methods (serotyping and macrorestriction analysis). In total 267 L. monocytogenes strains, 75 of human and 192 strains of RTE food origin were analysed. Serotype 1/2a was the predominant one in both groups of strains, it was confirmed in 67 human isolates (89.3%), followed by serotype 1/2b and group 4 serotypes (3 and 5 cases respectively). Also in food isolates, the serotype 1/2a was the most detected one (64.1%), followed by serotype 1/2b (17.2%), group 4 serotypes (14.1%) and serotype 1/2c (4.7%). Some serotypes have always been foodstuff specific, e.g. serotype 1/2c was detected only in meat products, while group 4 serotypes were not found in any isolate coming from a dairy product. Using macrorestriction analysis, the tested strains in this study displayed a high heterogeneity, especially in the dominant 1/2a serotype. Studying genetic characteristics of strains analysed in our study made it possible to discover or hint at the pathways of listeria spread.

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