External quality assurance scheme for typing of verocytotoxin-producing E. coli (VTEC)
This report presents the results of the second round of the external quality assurance scheme for typing of verocytotoxin-producing Escherichia coli. Conducted between December 2009 and June 2010, it included O:H serotyping, detection and typing of eae, vtx1, vtx2 and ehxA genes, phenotypic detection of verocytotoxin/shiga toxin-production, fermentation of sorbitol and production of β-glucuronidase and enterohaemolysin for VTEC.
An average of 78% of participating laboratories from EU/EEA countries were able to correctly O:H serotype the ten VTEC strains that were included in the EQA and correct phenotypic characterisation was generally very high.
Executive summary
ECDC’s external quality assurance (EQA) schemes are designed to evaluate the performance of laboratories, to identify areas for improvement in laboratory diagnostics relevant to disease surveillance and to ensure comparability of results between laboratories in EU/EEA countries.
The second EQA scheme for typing of verocytotoxin-producing Escherichia coli (VTEC) was commissioned by ECDC and produced by Statens Serum Institut, Denmark. Forty-five laboratories of the Food- and Waterborne Diseases Network (FWD-Net) from 38 countries participated, of which 23 were from the EU/EEA countries.
The main objective of this EQA scheme was to assess whether typing of verocytotoxin-producing Escherichia coli (VTEC) strains by laboratories within and outside the European Union was carried out uniformly and whether comparable results could be obtained.
The results highlight the importance of genotypic detection, together with the need for improvements in some laboratories regarding the detection methodology used for specific subtypes.
