Scientific journal

54 2015

Journal of Food and Nutrition Research
Summary No. 3 / 2015

Véghová, A. – Koreňová, J. – Minarovičová, J. – Drahovská, H. – Siekel, P. – Kaclíková, E.
Isolation and characterization of Listeria monocytogenes from the environment of three ewes’ milk processing factories in Slovakia
Journal of Food and Nutrition Research, 54, 2015, No. 3, s. 252-259

Eva Kaclíková, Food Research Institute, National Agricultural and Food Centre, Priemyselná 4, 82475 Bratislava, Slovakia. E-mail:

Received 26 February 2015; accepted 8 April 2015; published online 5 May 2015.

Summary: The aim of the study was to investigate the occurence and diversity of Listeria monocytogenes in three ewes’ milk processing factories in Slovakia, and to reveal its sources. A total of 639 samples from the cheese production chain were collected during the years 2011–2014, out of which 20 (3.1%) were found to be positive for L. monocytogenes. L. ivanovii was detected in two samples and other Listeria species in 309 (48.4%) samples. Sporadic L. monocytogenes contamination was observed in all three factories with 10% positive samples being the products, while 90% of positive samples were associated with the production environment. By molecular serotyping using multiplex polymerase chain reaction, the L. monocytogenes isolates were classified in three serogroups – 80% in serogroup IIa, 10% in serogroup IIc and 10% in serogroup IVb. Testing for markers specific for three epidemic clones (ECI–ECIII) produced negative results. Molecular diversity evaluation of isolated strains by AscI-restriction and pulsed-field gel electrophoresis (PFGE) resulted in strain discrimination into 14 clusters at 100% similarity. The observed occasional incidence of L. monocytogenes and high strain diversity indicated the origin of contamination from external sources.

Keywords: Listeria monocytogenes; molecular typing; serogrouping; pulsed-field gel electrophoresis; ewes’ cheese

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