Escherichia coli O104:H4

Escherichia coli EHEC O104: H4 is a rare hybrid strain of the bacterium Escherichia coli from the enteroaggregative Escherichia coli EAEC O104: H4 and an EHEC strain.

As the cause he is related to the HUS epidemic 2011. The "O" in the serological classification represents the lipopolysaccharide antigen of the cell wall, while the "H " stands for the flagellar antigen.

Emergence of the pathogenic strain EHEC O104: H4

The study conducted by BGI DNA sequencing confirmed that the pathogen identical with enteroaggregative Escherichia coli O104 EAEC to 90%: H4. How it originated, is not fully understood and there are two different hypotheses. Various authors see a formation through a transduction via a horizontal gene transfer by bacteriophages in African EAEC O104: H4. The aim of these EAEC strain acquired the ability to produce Shiga toxins An alternative view assumes that an as-yet unknown Shiga -2 -positive O104: H4 strain exists, of which both the pathogenic EHEC O104: H4 as and the non- pathogenic EAEC O104: H4 descended.

Characteristics of pathogenic EHEC O104: H4

Genome assembly and copy number analysis confirmed both that the Shiga toxin is present 2 ( stx2 ) prophage gene clusters in two different copy number and thus the characteristic feature of the genome of E. coli strain O104: H4.

The strain is characterized by the following genetic markers:

• Stx2 positive ( Shiga toxin 2)
• Ter positive ( tellurite anion resistance gene cluster),
• Eae negative ( eae encodes the adhesion protein intimin )
• β -lactamases ampC, AMPD, Ampe, AMPG, AMPH available.

For control measures within the framework of the EU's integrated approach to food safety, the European Commission exists for diseases caused by the epidemic strain O104: H4 are caused Shiga - toxin producing E. coli 2, a case definition. The E. coli serotype O104: H4 stx2 was isolated and first described in 2001 and discussed in connection with the illness of a woman in South Korea in 2006.