title: Multi-laboratory validation study of multilocus variable-number tandem repeat analysis (MLVA) for Salmonella enterica serovar Enteritidis, 2015.
abstract: Multilocus variable-number tandem repeat analysis (MLVA) is a rapid and reproducible typing method that is an important tool for investigation, as well as detection, of national and multinational outbreaks of a range of food-borne pathogens. Salmonella enterica serovar Enteritidis is the most common Salmonella serovar associated with human salmonellosis in the European Union/European Economic Area and North America. Fourteen laboratories from 13 countries in Europe and North America participated in a validation study for MLVA of S. Enteritidis targeting five loci. Following normalisation of fragment sizes using a set of reference strains, a blinded set of 24 strains with known allele sizes was analysed by each participant. The S. Enteritidis 5-loci MLVA protocol was shown to produce internationally comparable results as more than 90% of the participants reported less than 5% discrepant MLVA profiles. All 14 participating laboratories performed well, even those where experience with this typing method was limited. The raw fragment length data were consistent throughout, and the inter-laboratory validation helped to standardise the conversion of raw data to repeat numbers with at least two countries updating their internal procedures. However, differences in assigned MLVA profiles remain between well-established protocols and should be taken into account when exchanging data.
authors.affiliation: Public Health England, London, United Kingdom.
authors.forename: Tansy
authors.initials: T
authors.lastname: Peters
authors.affiliation: Scientific Institute of Public Health, Brussels, Belgium.
authors.forename: Sophie
authors.initials: S
authors.lastname: Bertrand
authors.affiliation: Statens Serum Institut, Copenhagen, Denmark.
authors.forename: Jonas T
authors.initials: JT
authors.lastname: Björkman
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Lin T
authors.initials: LT
authors.lastname: Brandal
authors.affiliation: Scottish Microbiology Reference Laboratories, Glasgow, United Kingdom.
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Brown
authors.affiliation: National Center for Epidemiology, Budapest, Hungary.
authors.forename: Tímea
authors.initials: T
authors.lastname: Erdõsi
authors.affiliation: National Institute for Public Health and the Environment, Bilthoven, The Netherlands.
authors.forename: Max
authors.initials: M
authors.lastname: Heck
authors.affiliation: National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Salha
authors.initials: S
authors.lastname: Ibrahem
authors.affiliation: European Centre for Disease Prevention and Control (ECDC), Solna, Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Johansson
authors.affiliation: Austrian Agency for Health and Food Safety, Graz, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Kornschober
authors.affiliation: European Centre for Disease Prevention and Control (ECDC), Solna, Sweden.
authors.forename: Saara M
authors.initials: SM
authors.lastname: Kotila
authors.affiliation: Institut Pasteur, Paris, France.
authors.forename: Simon
authors.initials: S
authors.lastname: Le Hello
authors.affiliation: National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Taru
authors.initials: T
authors.lastname: Lienemann
authors.affiliation: Scientific Institute of Public Health, Brussels, Belgium.
authors.forename: Wesley
authors.initials: W
authors.lastname: Mattheus
authors.affiliation: Statens Serum Institut, Copenhagen, Denmark.
authors.forename: Eva Møller
authors.initials: EM
authors.lastname: Nielsen
authors.affiliation: Laboratoire National de Santé, Dudelange, Luxembourg.
authors.forename: Catherine
authors.initials: C
authors.lastname: Ragimbeau
authors.affiliation: Public Health Agency of Canada, Winnipeg, Canada.
authors.forename: Jillian
authors.initials: J
authors.lastname: Rumore
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, USA.
authors.forename: Ashley
authors.initials: A
authors.lastname: Sabol
authors.affiliation: Statens Serum Institut, Copenhagen, Denmark.
authors.forename: Mia
authors.initials: M
authors.lastname: Torpdahl
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, USA.
authors.forename: Eija
authors.initials: E
authors.lastname: Trees
authors.affiliation: University Hospital Galway, Galway, Ireland.
authors.forename: Alma
authors.initials: A
authors.lastname: Tuohy
authors.affiliation: Public Health England, London, United Kingdom.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: de Pinna
mesh_terms: D002681:China / Q000453:epidemiology; D004196:Disease Outbreaks; D016021:Epidemiologic Studies; D005060:Europe / Q000453:epidemiology; D006801:Humans; D007753:Laboratories / Q000706:statistics & numerical data*; D018598:Minisatellite Repeats; D058889:Molecular Typing / Q000379:methods*; D058885:Multilocus Sequence Typing / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D010802:Phylogeny; D011237:Predictive Value of Tests; D062486:Public Health Surveillance / Q000379:methods; D015203:Reproducibility of Results; D012478:Salmonella Food Poisoning / Q000453:epidemiology; D012480:Salmonella Infections / Q000453:epidemiology / Q000382:microbiology*; D012477:Salmonella enteritidis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D020080:Tandem Repeat Sequences / Q000235:genetics*
keywords: Salmonella; food-borne infections; laboratory; laboratory surveillance; typing