Escherichia
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 commensal 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 (especially the model-organism lab strain E. coli K-12) 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.
However, some strains of E. coli are pathogens, and unlike many bacteria, E. coli can cause an
impressive array of diseases. A large number of 'enteropathogenic' strains cause intestinal disease, and 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. These non-diarrheagenic pathogens
(also called extraintestinal pathogenic E. coli, or ExPEC) can cause urinary-tract infections, peritonitis,
endocarditis, meningitis, and other diseases.
E. coli is also an animal pathogen, and in addition to the impact on the food supply, the possibility
of those strains being implicated in human disease cannot be ruled out. For example, an avian pathogenic E. coli (APEC)
strain appears closely related to characterized ExPEC strains.
For over 50 years E. coli was the sole species within the genus Escherichia,
but in 1973 a second species, E. blattae, was isolated from the hindgut of the cockroach Blatta orientalis.
Since then a number of other species have been described, including E. hermannii, E. vulneris, E. fergusonii, and E. albertii.
Except for E. blattae, which is a cockroach commensal lacking pathogenicity for humans and other animals,
the other Escherichia species are at least sometimes associated with diarrheagenic infections.
| Organism |
Isolate/Strain |
Genome Sequence Status |
Query Annotations |
Browse Genome |
| Escherichia |
| Escherichia
albertii
|
TW07627
|
Draft |
 |
 |
| Escherichia
coli
(EAEC)
|
042
|
Complete |
Download from Sanger |
N/A |
| Escherichia
coli
(EAEC)
|
101-1
|
Draft |
|
|
| Escherichia
coli
(UPEC)
|
536
|
Complete |
|
|
| Escherichia
coli
(EIEC)
|
53638
|
Draft |
|
|
| Escherichia
coli
(APEC)
|
APEC O1
|
Complete |
|
|
| Escherichia
coli
|
ATCC 8739
|
Complete |
|
|
| Escherichia
coli
(EPEC)
|
B171
|
Draft |
|
|
| Escherichia
coli
(EPEC)
|
plasmid pB171
|
Complete |
|
|
| Escherichia
coli
(ETEC)
|
B7A
|
Draft |
|
|
| Escherichia
coli
(UPEC)
|
CFT073
|
Complete |
|
|
| Escherichia
coli
(EPEC)
|
E110019
|
Draft |
|
|
| Escherichia
coli
(EPEC)
|
E22
|
Draft |
|
|
| Escherichia
coli
(EPEC)
|
E2348/69
|
Complete |
|
|
| Escherichia
coli
(EPEC)
|
plasmid pMAR7
|
Complete |
|
|
| Escherichia
coli
(ETEC)
|
E24377A
|
Complete |
|
|
| Escherichia
coli
(EHEC)
|
EC4024
|
Draft |
|
|
| Escherichia
coli
(EHEC)
|
EC4042
|
Draft |
|
|
| Escherichia
coli
(EHEC)
|
EC4045
|
Draft |
|
|
| Escherichia
coli
(EHEC)
|
EC4076
|
Draft |
|
|
| Escherichia
coli
(EHEC)
|
EC4113
|
Draft |
|
|
| Escherichia
coli
(EHEC)
|
EC4115
|
Complete |
|
|
| Escherichia
coli
(EHEC)
|
EC4196
|
Draft |
|
|
| Escherichia
coli
(EHEC)
|
EC4206
|
Draft |
|
|
| Escherichia
coli
(EHEC)
|
EC4401
|
Draft |
|
|
| Escherichia
coli
(EHEC)
|
EC4486
|
Draft |
|
|
| Escherichia
coli
(EHEC)
|
EC4501
|
Draft |
|
|
| Escherichia
coli
(EHEC)
|
EC508
|
Draft |
|
|
| Escherichia
coli
(EHEC)
|
EC869
|
Draft |
|
|
| Escherichia
coli
(EHEC)
|
EDL933
|
Complete |
|
|
| Escherichia
coli
(UPEC)
|
F11
|
Draft |
|
|
| Escherichia
coli
(ETEC)
|
H10407
|
Complete |
Not Yet Available |
N/A |
| Escherichia
coli
|
HS
|
Complete |
|
|
| Escherichia
coli
(ETEC)
|
plasmid pCoo
|
Complete |
|
|
| Escherichia
coli
|
plasmid F
|
Complete |
|
|
| Escherichia
coli
|
K-12 substrain DH10B
|
Complete |
|
|
| Escherichia
coli
|
K-12 substrain MG1655
|
Complete |
|
|
| Escherichia
coli
|
K-12 substrain W3110
|
Complete |
|
|
| Escherichia
coli
|
SE11
|
Complete |
|
|
| Escherichia
coli
|
SMS-3-5
|
Complete |
|
|
| Escherichia
coli
(EHEC)
|
Sakai
|
Complete |
|
|
| Escherichia
coli
(EHEC)
|
TW14588
|
Draft |
|
|
| Escherichia
coli
(UPEC)
|
UTI89
|
Complete |
|
|
| Escherichia
fergusonii
|
ATCC 35469
|
Complete |
|
|
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.
Escherichia coli
Escherichia coli B
Escherichia coli K12
Escherichia coli O6
Web Resources:
Pathogenic E. coli
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
EcoliHub
EcoCyc
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