Common Diseases > E-Coli
Commonly abbreviated as 'E. coli', Escherichia coli is a generic term for a
large diverse group of bacteria commonly found in the lower intestine of
warm-blooded organisms (including mammals and birds) of which most strains are
The harmless strains are part of the normal flora of the gut, benefiting their
hosts by producing vitamin K2, and preventing the establishment of pathogenic
bacteria within the intestine.
As a medicine, Nonpathogenic Escherichia coli strain 'Nissle 1917' also known as
'Mutaflor' is used as a probiotic agent for the treatment of various
gastroenterological diseases, including inflammatory bowel disease.
While most E. coli strains are harmless, some can cause illness with symptoms
including stomach cramps, diarrhea and vomiting, such as serotype O157:H7 which
can cause serious food poisoning in humans.
Other Virulent strains of E. coli can cause gastroenteritis, urinary tract
infections, and neonatal meningitis. In rarer cases, virulent strains are also
responsible for haemolytic-uremic syndrome, peritonitis, mastitis, septicaemia
and Gram-negative pneumonia.
Food poisoning caused by E. coli is usually caused by eating unwashed vegetables
or undercooked meat. O157:H7 is also notorious for causing serious and even
life-threatening complications such as Hemolytic-uremic syndrome. This
particular strain is linked to the 2006 United States E. coli outbreak due to
Certain strains of E. coli, such as O157:H7, O121, O26, O103, O111, O145,and
O104:H21, produce potentially lethal toxins and normally these are effectively
treated with antibiotics while the 2011 outbreak in Germany represents a new
“supertoxic” (HUS) strain of the E.coli bacteria which carries several genes
making it resistant to antibiotic treatments and very difficult to treat.
The bacterium latches on to the intestinal wall and produces toxins that cause
bloody diarrhoea and, later, haemolytic uraemic syndrome and kidney failure. The
consequences can be fatal, but, even for survivors, the long-term consequences
are grave. Patients with damaged kidneys need transplants, and damage done to
the nervous system may never be reversed.
In 2010, two German toddlers fell victim to a serious E.coli infection. After
suffering from bloody diarrhoea and falling into a coma for 10 days, one can no
longer walk or talk; the other is blind. The two children are in rehabilitation
but will never return to full health.
The bacteria E. coli is a Gram-negative rod-shaped bacterium which can be grown
easily in laboratories and its genetics are comparatively simple and easily
manipulated or duplicated through a process of metagenics, making it one of the
best-studied prokaryotic model organisms, and an important species in
biotechnology and microbiology.
E. coli are not always confined to the intestine, and their ability to survive
for brief periods outside the body makes them an ideal indicator organism to
test environmental samples for fecal contamination.
Regular hand washing, particularly before food preparation or consumption and
after toilet contact, is highly recommended, particularly for people who care
for small children or are immunocompromised, as the bacterium can be passed from
person to person, as well as through food, water and direct contact with
animals. As in the 2011 outbreak in Germany, foods are best eaten well cooked
with close attention to good kitchen hygiene.
World Health Organisation