''Escherichia'' () is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
of
Gram-negative
Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wa ...
, non-
spore-forming,
facultatively anaerobic
A facultative anaerobic organism is an organism that makes ATP by aerobic respiration if oxygen is present, but is capable of switching to fermentation if oxygen is absent.
Some examples of facultatively anaerobic bacteria are ''Staphylococcus' ...
, rod-shaped
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...
from the family
Enterobacteriaceae.
In those species which are inhabitants of the
gastrointestinal tracts of
warm-blooded
Warm-blooded is an informal term referring to animal species which can maintain a body temperature higher than their environment. In particular, homeothermic species maintain a stable body temperature by regulating metabolic processes. The onl ...
animals, ''Escherichia'' species provide a portion of the microbially derived
vitamin K
Vitamin K refers to structurally similar, fat-soluble vitamers found in foods and marketed as dietary supplements. The human body requires vitamin K for post-synthesis modification of certain proteins that are required for blood coagulation ...
for their host. A number of the species of ''Escherichia'' are
pathogen
In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...
ic. The genus is named after
Theodor Escherich, the discoverer of ''
Escherichia coli
''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus '' Esc ...
''. ''Escherichia'' are facultative aerobes, with both aerobic and anaerobic growth, and an optimum temperature of 37 °C.
''Escherichia'' are usually motile by
flagella, produce gas from fermentable carbohydrates, and do not decarboxylate
lysine or hydrolyze
arginine.
Species include ''
E. albertii'', ''
E. fergusonii'', ''
E. hermannii'', ''
E. marmotae'' and most notably, the
model organism and clinically relevant ''
E. coli''. ''
Shimwellia blattae'' was formerly classified in this genus.
Pathogenesis
While many ''Escherichia'' are commensal members of the
gut microbiota, certain strains of some species, most notably the
pathogenic serotypes of ''
E. coli'', are human pathogens,
and are the most common cause of
urinary tract infection
A urinary tract infection (UTI) is an infection that affects part of the urinary tract. When it affects the lower urinary tract it is known as a bladder infection (cystitis) and when it affects the upper urinary tract it is known as a kidne ...
s,
significant sources of gastrointestinal disease, ranging from simple
diarrhea
Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin w ...
to
dysentery
Dysentery (UK pronunciation: , US: ), historically known as the bloody flux, is a type of gastroenteritis that results in bloody diarrhea. Other symptoms may include fever, abdominal pain, and a feeling of incomplete defecation. Complications ...
-like conditions,
as well as a wide range of other pathogenic states
classifiable in general as colonic escherichiosis. While ''E. coli'' is responsible for the vast majority of ''Escherichia''-related pathogenesis, other members of the genus have also been implicated in human disease.
''Escherichia'' are associated with the imbalance of
microbiota of the lower reproductive tract of women. These species are associated with inflammation.
See also
*
''E. coli'' O157:H7
*
List of bacterial genera named after personal names
Many bacterial species are named after people, either the discoverer or a famous person in the field of microbiology. For example, ''Salmonella'' is named after D.E. Salmon, who discovered it (albeit as "''Bacillus typhi''").
For the generic epit ...
References
External links
Escherichiagenomes and related information a
PATRIC a Bioinformatics Resource Center funded b
NIAID
{{Taxonbar, from=Q311055
Gut flora bacteria
Gram-negative bacteria
Pathogenic bacteria
Bacteria genera