Diarrheagenic Escherichia coli
Escherichia is named after German bacteriologist Theodore Escherich (1857-1911), who first described
them in 1885. They are Gram-negative non-sporeforming, rod-shaped bacteria, often motile and possessing a
facultative metabolism.
The species Escherichia coli is a normal inhabitant of the large intestine of warm-blooded animals.
Easy to grow, with a fast doubling time, E. coli has become the 'lab rat' of the bacterial world.
This was reinforced by the discovery of 'bacterial sex' in E. coli, for which Joshua Lederberg
shared the Nobel Prize in 1958. E. coli has been widely used as a model in molecular biology
studies, and more detail is known about the molecular biology of this organism than any other, including
humans.(see Reference Genomes)
However, some strains of E. coli are 'enteropathogenic' strains that can cause intestinal disease.
These diarrheagenic E. coli strains are further subdivided on the basis of the symptomology of
infections, aka virotype (listed below). Pathogenesis among E. coli is associated with the
possession of virulence factors, often encoded by plasmids, bacteriophage, or 'islands' integrated into the
chromosome. It is likely that these factors, not all of which have been identified, are traded and
reassorted among E. coli and the other Enterobacteriaceae via lateral, or horizontal, gene
transfer. The diarrheagenic E. coli are transmitted via the fecal-oral route, either from
person-to-person or from contaminated food or water sources. Domestic, agricultural, and wild animals, as
well as humans, can be sources of contamination. Some strains, including many enterohemorrhagic (EHEC)
isolates, are resistant to stomach acid and have infectious doses as low as 10 organisms.
- Enterotoxigenic E. coli (ETEC) is a common cause of traveler's diarrhea and diarrhea in infants
- both human and livestock. These strains usually encode adhesins (colonization factor antigens, or
CFAs) that allow them to adhere to and colonize the intestinal epithelium. Once established, they
secrete one or more toxins - one similar to cholera toxin - eliciting nausea, vomiting, abdominal
cramps, and massive watery diarrhea leading to dehydration. In infants, the dehydration is often fatal
if not treated.
- Enteroinvasive E. coli (EIEC) are able to invade and multiply within intestinal epithelial
cells, resulting in cell destruction, intense inflammation, and ulceration of the intestinal lining.
With symptoms of fever, cramps, vomiting, and bloody diarrhea, the disease closely resembles that caused
by Shigella
spp.
- Enteropathogenic E. coli (EPEC) cause diarrheal outbreaks and chronic diarrhea, especially in
infants. After an initial association with intestinal epithelial cells, these strains elicit a response
in the host cells resulting in the loss of microvilli and the formation of a platform, or pedestal, of
actin fibrils at the site of bacterial attachment. The disease, manifesting as fever, vomiting, and a
watery mucus-containing diarrhea, is associated with a limited number of E. coli serotypes. As
with ETEC, the diarrhea can be fatal in infants and children, especially in developing countries.
- Enterohemorrhagic E. coli (EHEC) are similar to EPEC strains, but often produce severe illness
including bloody diarrhea. These strains encode potent toxins similar if not identical to those of Shigella
dysenteriae, which can cause the damage of intestinal epithelial cells, and interfere with protein
biosynthesis in endothelial cells lining the microvasculature of the kidney and central nervous system.
Among infected individuals, 2% to 7% develop hemolytic uremic syndrome (HUS), marked by red blood cell
lysis and kidney failure. Fatality is common, especially among infants and the elderly. As with EPEC
strains, EHEC are associated with a limited number of serotypes, and in the United States a single
serological type, O157:H7, is the predominant representative.
- Enteroaggregative E. coli (EAEC) form aggregates of bacteria, many cells thick, which are
quite distinct from the more isolated patches of bacterial cells typical of ETEC, EPEC, and EHEC
strains. This aggregation may correlate with the persistent diarrhea caused by these strains.
- Diffusely adherent E. coli (DAEC), as the name suggests, form a much more dispersed association
with host cells. They have been reported as being associated with diarrhea in some studies, but not in
others. They have also been implicated with recurrent urinary tract infections.
Other strains of E. coli leave the intestinal habitat altogether, and cause urinary-tract
infections, peritonitis, endocarditis, meningitis, and other diseases. Unlike many bacteria, E.
coli can cause an impressive array of diseases.
(see Reference Genomes)
| Organism |
Isolate/Strain |
Genomic Sequence Status |
Query Annotations |
Browse Genome |
| Diarrheagenic Escherichia
coli
|
| Enterohemorrhagic Escherichia coli
(EHEC)
|
EC869 |
Draft assembly |
 |
 |
| Enterohemorrhagic Escherichia coli
(EHEC)
|
EC4042 |
Draft assembly |
|
|
| Enterohemorrhagic Escherichia coli
(EHEC)
|
EC4045 |
Draft assembly |
|
|
| Enterohemorrhagic Escherichia coli
(EHEC)
|
EC4076 |
Draft assembly |
|
|
| Enterohemorrhagic Escherichia coli
(EHEC)
|
EC4113 |
Draft assembly |
|
|
| Enterohemorrhagic Escherichia coli
(EHEC)
|
EC4115 |
Draft assembly |
|
|
| Enterohemorrhagic Escherichia coli
(EHEC)
|
EC4196 |
Draft assembly |
|
|
| Enterohemorrhagic Escherichia coli
(EHEC)
|
EC4206 |
Draft assembly |
|
|
| Enterohemorrhagic Escherichia coli
(EHEC)
|
EC4401 |
Draft assembly |
|
|
| Enterohemorrhagic Escherichia coli
(EHEC)
|
EC4486 |
Draft assembly |
|
|
| Enterohemorrhagic Escherichia coli
(EHEC)
|
EC4501 |
Draft assembly |
|
|
| Enterohemorrhagic Escherichia coli (EHEC) |
EDL933 |
Sequencing complete |
|
|
| Enterohemorrhagic Escherichia coli
(EHEC)
|
Sakai |
Sequencing complete |
|
|
| Enteroaggregative Escherichia coli (EAEC) |
101-1 |
Draft Assembly |
|
|
| Enteroaggregative Escherichia coli (EAEC) |
042 |
Sequencing complete |
Download
from Sanger |
N/A |
| Enteropathogenic Escherichia coli (EPEC) |
E2348/69 |
Finishing/gap closure |
Download from
Sanger |
N/A |
| Enteropathogenic Escherichia coli (EPEC) |
plasmid pMAR7 |
Sequencing complete |
|
|
| Enteropathogenic Escherichia coli (EPEC) |
E22 |
Draft assembly |
|
|
| Enteropathogenic Escherichia coli (EPEC) |
B171 |
Draft assembly |
|
|
| Enteropathogenic Escherichia coli (EPEC) |
plasmid pB171 |
Sequencing complete |
|
|
| Enteropathogenic Escherichia coli (EPEC) |
E110019 |
Draft Assembly |
|
|
| Enterotoxigenic Escherichia coli (ETEC) |
B7A |
Draft assembly |
|
|
| Enterotoxigenic Escherichia coli (ETEC) |
E24377A |
Sequencing complete |
|
|
| Enterotoxigenic Escherichia coli (ETEC) |
H10407 |
Draft assembly |
Download from Sanger |
N/A |
| Enterotoxigenic Escherichia coli (ETEC) |
plasmid pCoo |
Sequencing complete |
|
|
| Enteroinvasive Escherichia coli (EIEC) |
53638 |
Draft assembly |
|
|
Immune Epitope Database Links:
Escherichia coli
Escherichia coli O157:H7
A link to E. coli IEDB records is provided since many of the epitopes are not characterized at a strain specific level and they may or may not be present in a specific E. coli strain of interest.
Web Resources:
E. coli as Pathogens
NCBI's MedlinePlus Medical
Encyclopedia
- E. coli enteritis
Latest Foodborne Pathogen Scientific News
NCBI's MedlinePlus Health Topics - E. coli Infections
NCBI's MedlinePlus Medical Encyclopedia - Hemolytic-
uremic syndrome
CDC's Disease Information Pages:
Diarrheagenic Escherichia
coli (non-Shiga toxin-producing E. coli)
Enterohemorrhagic Escherichia
coli
Escherichia coli
O157:H7
Enterotoxigenic Escherichia
coli
(ETEC)
FDA's Center for Food Safety & Applied Nutrition:
Escherichia coli - enterotoxigenic
(ETEC)
Escherichia coli - enteropathogenic
(EPEC)
Escherichia coli O157:H7
enterohemorrhagic
(EHEC)
Escherichia coli - enteroinvasive
(EIEC)
HHS.gov
NIH.gov
NIAID