Infectious Diseases 2019

Infectious Diseases 2019

EURL-Salmonella interlaboratory comparison study (2017)

3 January, 2019

In November 2017, the 22nd interlaboratory comparison study on the typing of Salmonella was organised by the European Union Reference Laboratory for Salmonella (EURL-Salmonella, Bilthoven, the Netherlands). The study’s main objective was to evaluate whether the typing of Salmonella strains by the National Reference Laboratories (NRLs-Salmonella) in the European Union was carried out uniformly, and whether comparable results were being obtained. Performance of EU NRLs in Salmonella typing is assessed annually by testing ability to identify 20 strains. NRLs from countries outside the EU participate on a voluntary basis. The Former Yugoslav Republic of Macedonia and Serbia as well as Iceland, Norway, Switzerland and Israel took part in the 2017 assessment. All 35 labs performed serotyping. Twenty obligatory Salmonella strains plus one optional strain were selected by the EURL-Salmonella for serotyping. They had to be typed according to the method routinely used in each lab, following the White-Kauffmann-Le Minor scheme (Grimont and Weill, 2007). The laboratories were allowed to send strains for serotyping to another specialised laboratory in their country if this was part of their usual procedure. Overall, 99% of the strains were typed correctly for the O-antigens, 98% of the strains were typed correctly for the H-antigens, and 98% of the strains were correctly named by the participants. All 35 participants achieved good results in the first stage of the study, therefore a followup was not necessary.