Escherichia coli EEC
coli are bacteria belonging
the family Enterobacteriaceae. E. coli is a normal
inhabitant of the intestines of all animals, including humans however
some types cause disease. Normally E. coli serves
a useful function in the body by suppressing the growth of harmful
bacterial species and by synthesizing appreciable amounts of vitamins.
are 4 classes of enterovirulent E. coli (collectively
referred to as the EEC group) that cause gastroenteritis in humans.
Escherichia coli (ETEC)
the enterotoxigenic (ETEC) strains. They cause diarrhea in infants
in developing countries and in travelers. Gastroenteritis is the
common name of this disease although it is also frequently called
travelers' diarrhea. Common symptoms include watery diarrhea, abdominal
cramps, nausea and malaise.
contamination with human sewage contaminates foods. As well as infected
food handlers. These organisms are in dairy products such as semi-soft
Escherichia coli (EPEC)
the enteropathogenic (EPEC) strains are defined as E. coli
belonging to serogroups epidemiological implicated as pathogens
but whose virulence mechanism is unrelated to the excretion of typical
E. coli enterotoxins.
borne outbreaks are sporadic. Humans, cows, and pigs can be infected.
diarrhea is the name of the disease usually associated with EPEC
cause either a watery or bloody diarrhea. Bloody diarrhea is associated
with bacteria attachment and possibly a toxin similar to that of
are highly infectious for infants.
infant diarrhea is prolonged, leading to dehydration, electrolyte
imbalance and death.
the enterohemorrhagic (EHEC) strain designated E. coli
serotype O157:H7 that produces
large quantities of one or more toxins that cause severe damage
to the lining of the intestine. These toxins [verotoxin (VT), shiga-like
toxin] are closely related or identical to the toxin produced by
colitis is the name of the acute disease caused by E. coli
O157:H7 (also called "hamburger disease")
is characterized by cramping abdominal pain and diarrhea, which
is watery but becomes bloody. Occasionally vomiting occurs. Fever
is either low-grade or absent. The illness is usually self-limited
and lasts for an average of 8 days. Some individuals have watery
colitis is found by identification of E. coli of serotype
O157:H7 or other verotoxin-producing E. coli from diarrheal
stools. Alternatively, the stools can be tested directly for the
presence of verotoxin. Confirmation can be obtained by isolating
of E. coli of the same serotype from the incriminated
or raw hamburger (ground beef) has been implicated in many outbreaks,
as well as alfalfa sprouts, unpasteurized fruit juices, dry-cured
salami, lettuce, game meat, raw milk and cheese curds.
particularly the very young, develop hemolytic uremic syndrome (HUS),
characterized by renal failure and hemolytic anemia. From 0 to 15%
of hemorrhagic colitis victims develop HUS with loss of kidney function.
complications particularly in the elderly involve HUS, with two
other symptoms, fever and neurological symptoms, constitutes thrombotic
thrombocytopenic purpura (TTP).
agar has been used extensively to isolate this organism.. Rapid
methods using a variety of technologies, including recombinant DNA
methods, are being developed.
MMWR 45(30):1996, MMWR
49(15):2000 , MMWR
are the enteroinvasive (EIEC) strains.cause a form of bacillary
dysentery. Enteroinvasive E. coli (EIEC) causes bacillary
dysentery. The EIEC strains responsible for this syndrome are similar
to Shigella spp. The EIEC invade the intestine, causing
dysentery, with blood and mucus in the stools of infected individuals.
Any food contaminated with human feces from an ill individual, could
spread disease. Outbreaks have been associated with hamburger meat
and unpasteurized milk.
caused by EIEC occurs within 12 to 72 hours after eating contaminated
food. With abdominal cramps, diarrhea, vomiting, fever, chills,
and generalized malaise. Dysentery is generally self-limiting but
cases of hemolytic uremic syndrome (HUS) could develop.
stool cultures are examined .Detection of this organism in foods is