Thisted Lambertz, Susanne
- National Food Agency
Abstract
Identification and prioritisation of food safety interventions requires an understanding of the relationship between food, pathogens and cases. Such understanding can be gained through different approaches, e.g. microbial subtyping to attribute cases of foodborne disease to food vehicles or other sources of illness. In this study, Listeria monocytogenes isolates (n = 166) from (i) three categories of ready-to-eat (RTE) foods, (ii) food processing plant environments, and (iii) human listeriosis cases, all sampled during 2010 in Sweden, were subtyped. In addition, 121 isolates from human listeriosis cases, collected 2005-2009, were subtyped. Subtyping consisted of both serotyping (conventional method and PCR) and genotyping using pulsed-field gel electrophoresis (PFGE). Serotype 1/2a dominated in all three groups of isolates (range 73-96%). Eighteen percent of the human isolates (2010) belonged to serotype 4b, but only 1.4% of the food isolates. The food isolates differentiated into 19 pulsotypes (ID = 0.843), the human isolates collected 2010 into 31 pulsotypes (ID = 0.950) and the processing plant isolates into 22 pulsotypes (ID = 0.991). Six of the pulsotypes were shared between the food and human isolates. These pulsotypes comprised 42% of the human isolates and 59% of the food isolates. For some processing plants, there was suggested persistence of one or more specific L. monocytogenes strains, as indicated by repetitive isolation of the same pulsotype from food. This study indicated the presence of L. monocytogenes in the processing plant environment as a likely source of contamination of gravad and cold-smoked fish, and this food category as an important source of human exposure to the pathogen. (C) 2013 Elsevier B.V. All rights reserved.
Keywords
Listeria monocytogenes; Typing; PFGE
Published in
International Journal of Food Microbiology
2013, volume: 166, number: 1, pages: 186-192
Publisher: ELSEVIER SCIENCE BV
SLU Authors
Lindqvist, Roland
- Department of Molecular Sciences, Swedish University of Agricultural Sciences
- National Food Agency
- Department of Molecular Sciences, Swedish University of Agricultural Sciences
Global goals (SDG)
UKÄ Subject classification
Microbiology
Food Science
Publication identifier
- DOI: https://doi.org/10.1016/j.ijfoodmicro.2013.06.008
Permanent link to this page (URI)
https://res.slu.se/id/publ/53071