O104:H4 Shiga-toxic Escherichia coli

German outbreak STEC strain available

The O104:H4 Shiga-toxic Escherichia coli (STEC) strain, designated NCTC 13562, responsible for the largest recorded STEC outbreak of haemolytic uraemic syndrome and bloody diarrhoea is available from UK Health Security Agency's (UKHSA) National Collection of Type Cultures (NCTC). The outbreak occurred in Germany in 2011, affecting 3900 people and resulting in 53 deaths.  This is a poignant reminder of the importance of making authenticated reference strains available for the research community to combat the emergence of new highly virulent bacterial strains.

STEC is a pathogenic variant of a microorganism that is found commonly in the intestines of people and animals, the environment, food and water and is part of the gut flora of healthy humans.

STEC organisms can cause mild gasteroenteritis, bloody diarrhoea and haemolytic uremic syndrome (HUS) which can be fatal. The toxins produced by this organism are highly similar to those produced by Shigella dysenteriae, the cause of bacillary dysentery.

Most STEC infections are caused by E.coli organisms in the O157 serogroup, causing more than 800 cases of illness in England and Wales every year and primarily affecting the young (0-5 years) and the old (75+ years). In 2009, an outbreak of E.coli O157 in Surrey resulted in in 17 children being hospitalised with HUS.

The O104:H4 strain responsible for the outbreak in 2011 was particularly virulent, causing a higher percentage of cases of HUS than expected, and is resistant to a wide range of antibiotics.  It was difficult to detect due to its uncommon serotype and unusual genotype.

NCTC provides a range of STEC strains including both toxigenic and non-toxigenic strains of the O157 serogroup.

Authenticated NCTC organisms provided by UKHSA are used by the research community to understand how shiga-toxic E.coli strains cause disease, and to support the work of healthcare professionals and clinicians in rapid diagnosis.