title: Evaluation of molecular typing of foodborne pathogens in European reference laboratories from 2012 to 2013.
abstract: In 2012, the European Centre for Disease Prevention and Control (ECDC) initiated external quality assessment (EQA) schemes for molecular typing including the National Public Health Reference Laboratories in Europe. The overall aim for these EQA schemes was to enhance the European surveillance of food-borne pathogens by evaluating and improving the quality and comparability of molecular typing. The EQAs were organised by Statens Serum Institut (SSI) and included Salmonella enterica subsp. enterica, verocytotoxin-producing Escherichia coli (VTEC) and Listeria monocytogenes. Inter-laboratory comparable pulsed-field gel electrophoresis (PFGE) images were obtained from 10 of 17 of the participating laboratories for Listeria, 15 of 25 for Salmonella, but only nine of 20 for VTEC. Most problems were related to PFGE running conditions and/or incorrect use of image acquisition. Analysis of the gels was done in good accordance with the provided guidelines. Furthermore, we assessed the multilocus variable-number tandem repeat analysis (MLVA) scheme for S. Typhimurium. Of 15 laboratories, nine submitted correct results for all analysed strains, and four had difficulties with one strain only. In conclusion, both PFGE and MLVA are prone to variation in quality, and there is therefore a continuous need for standardisation and validation of laboratory performance for molecular typing methods of food-borne pathogens in the human public health sector.
authors.affiliation: Unit of foodborne infections, Department of Microbiology and Infection Control, Statens Serum Institut (SSI), Copenhagen, Denmark.|European Programme for Public Health Microbiology Training (EUPHEM), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden.
authors.forename: Susanne
authors.initials: S
authors.lastname: Schjørring
authors.affiliation: Food and Waterborne Diseases and Zoonoses Programme, European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden.
authors.forename: Taina
authors.initials: T
authors.lastname: Niskanen
authors.affiliation: Unit of foodborne infections, Department of Microbiology and Infection Control, Statens Serum Institut (SSI), Copenhagen, Denmark.
authors.forename: Mia
authors.initials: M
authors.lastname: Torpdahl
authors.affiliation: Unit of foodborne infections, Department of Microbiology and Infection Control, Statens Serum Institut (SSI), Copenhagen, Denmark.
authors.forename: Jonas T
authors.initials: JT
authors.lastname: Björkman
authors.affiliation: Unit of foodborne infections, Department of Microbiology and Infection Control, Statens Serum Institut (SSI), Copenhagen, Denmark.
authors.forename: Eva Møller
authors.initials: EM
authors.lastname: Nielsen
mesh_terms: D004269:DNA, Bacterial / Q000032:analysis; D016521:Electrophoresis, Gel, Pulsed-Field / Q000592:standards*; D016021:Epidemiologic Studies; D004926:Escherichia coli / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology; D005060:Europe; D005517:Foodborne Diseases / Q000382:microbiology*; D006801:Humans; D007753:Laboratories; D008089:Listeria monocytogenes / Q000235:genetics* / Q000302:isolation & purification; D008088:Listeriosis / Q000382:microbiology; D018598:Minisatellite Repeats; D058889:Molecular Typing / Q000379:methods / Q000592:standards*; D012480:Salmonella Infections / Q000382:microbiology; D019779:Salmonella enterica / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial
keywords: Listeria; MLVA; PFGE; Salmonella; VTEC; surveillance