Escherichia coli O104:H4
Escherichia coli O104:H4 is an enteroaggregative Escherichia coli strain of the bacterium Escherichia coli, and the cause of the 2011 Escherichia coli O104:H4 outbreak. The "O" in the serological classification identifies the cell wall lipopolysaccharide antigen, and the "H" identifies the flagella antigen.
| Escherichia coli O104:H4 | |
|---|---|
| Scientific classification | |
| Domain: | Bacteria |
| Phylum: | Pseudomonadota |
| Class: | Gammaproteobacteria |
| Order: | Enterobacterales |
| Family: | Enterobacteriaceae |
| Genus: | Escherichia |
| Species: | E. coli |
| Strain: | E. c. O104:H4 |
| Trionomial name | |
| Escherichia coli O104:H4 | |
Analysis of genomic sequences obtained by BGI Shenzhen shows that the O104:H4 outbreak strain is an enteroaggregative E. coli (EAEC or EAggEC) type that has acquired Shiga toxin genes, presumably by horizontal gene transfer.
Genome assembly and copy-number analysis both confirmed that two copies of the Shiga toxin stx2 prophage gene cluster are a distinctive characteristic of the genome of the O104:H4 outbreak strain. The O104:H4 strain is characterized by these genetic markers:
- Shiga toxin stx2 positive
- tellurite resistance gene cluster positive
- intimin adherence gene negative
- β-lactamases ampC, ampD, ampE, ampG, ampH are present.
The European Commission (EC) integrated approach to food safety defines a case of Shiga-like toxin-producing E. coli (STEC) diarrhea caused by O104:H4 by an acute onset of diarrhea or bloody diarrhea together with the detection of the Shiga toxin 2 (Stx2) or the Shiga gene stx2.
Prior to the 2011 outbreak, only one case identified as O104:H4 had been observed, in a woman in South Korea in 2005.