Berlin / DE. (bfr) A specific detection system for the EHEC germ O104:H4 in foods has been developed and evaluated at the National Reference Laboratory (NRL) for Escherichia coli of the German Federal Institute for Risk Assessment (BfR) together with experts from the French Food Agency, ANSES. The EHEC strain O104:H4 is responsible for the current outbreak of EHEC infections with severe health effects, which range from bloody diarrhoea to kidney failure. «We hope that this test will contribute towards identifying the source of the infections with the EHEC strain O104:H4, to withdraw the risk-laden foods rapidly from the market and obtain clarity about the infection chain», says BFR President Professor Dr. Dr. Andreas Hensel. BfR has by now made the method available to the diagnostic laboratories of the Federal States (Laender).
A rapid and reliable test for the detection of the EHEC strain O104:H4 in foods had so far not been available in Germany. For that reason foods contaminated by this specific germ could not yet be identified. Although individual contaminations of vegetables with Shiga toxin-producing germs had been detected, it could not be confirmed that they belong to the outbreak strain EHEC O104:H4.
The method with which the pathogen O104:H4, also referred to as HUSEC 41, was detected in patients affected by EHEC infections in Germany, is a classical multiplex polymerase chain reaction (PCR). It is not yet known whether this method is suited for foods. Under the impression of the massive EHEC O104:H4 outbreak in Germany, a specific quantitative real-time PCR has now been tested at the National Reference laboratory for Escherichia coli of BfR in food samples and O104:H4 reference strains. It is based on a rapid, quantitative detection of Shiga toxin genes and the Escherichia coli O104:H4 wzx gene. The detection system can identify EHEC O104:H4 in enrichment cultures of suspected foods. First vegetable foods originating from Mecklenburg-Vorpommern and Berlin have already been analysed with the method. EHEC was not detected.
