2. What is E. coli?
E.coli (Escherichia coli) are a large and multiform
group of bacteria that lives in the intestines of
animals and people.
Most strains of E.coli are harmless, others can make
you very sick. Some kinds of E. coli can cause
diarrhea, while others cause respiratory illness,
urinary tract infections, pneumonia, and other
illnesses.
3. Signs & symptoms
Abdominal pain - typically, the first symptom is severe abdominal cramping that
comes on suddenly.
Diarrhea - a few hours after the sudden abdominal pain, the patient typically has
watery diarrhea. A day later there may be bright red bloody stools, caused by sores in
the intestines.
Nausea
Vomiting
Fever
Fatigue - diarrhea causes loss of fluids and electrolytes (dehydration), making the
patient feel sick and tired
4. Morphology & Cell Type
E COLI IS A SINGLE CELLED PROKAROYOTIC ORGANISM.
E COLI IS GRAM-NEGATIVE.
IT IS A BACILLUS BACTERIUM SO IT IS ROD-SHAPED IN STRUCTURE.
E COLI LOOKS LIKE A LITTLE TUBE WITH HAIRLIKE PROJECTIONS AND A TAIL
ATTACHED (WHICH REPRESENTS A FLAGELLA).
E COLI POSSESSES ADHESIVE FIMBRIAE AND A CELL WALL THAT CONSISTS OF AN
OUTER MEMBRANE CONTAINING LIPOPOLYSACCHARIDES, A PERIPLASMIC SPACE
WITH PEPTIDOGLYCAN LAYER, AND AN INNER CYTOPLASMIC MEMBRANE.
EVEN THOUGH E COLI HAS AN EXTREMELY SIMPLE CELL STRUCTURE, WITH ONLY
ONE CHROMOSOMAL DNA AND A PLASMID, IT CAN PERFORM COMPLICATED
METABOLISM TO MAINTAIN ITS CELL GROW AND CELL DIVISION.
6. Virulence Factors
Virulence factors of Escherichia coli are of two main types; those
produced on the surface of the cell and those produced within the
cell and then exported to the site of action.
Those on the surface include different sorts of fimbriae that have a
role in adhesion to the surface of host cells but may also have
additional roles such as tissue invasion, biofilm formation or cytokine
induction.
Other virulence factors enable the bacteria to grow in an
environment of iron restriction.
7. Virulence Factors
Shiga toxin enters cells and stops the cells from producing proteins it needs
to function. Without the ability to sustain its function, the cell dies
P fimbriae are responsible for adhesion to mucosal and tissue matrix and
for the production of cytokines
S fimbriae may facilitate bacterial dissemination within host tissues and are
often associated with E. coli strains that cause sepsis, meningitis, and
ascending UTIs
Flagella an organelle responsible for bacterial motility, is involved in the
interaction of various pathogenic E. coli strains with epithelial cells.
8. More Virulence Factors
Virulence factors located on the bacterial surface include the capsule
and the lipopolysaccharide (LPS).
The capsule provides protection against phagocytic engulfment and
complement-mediated bactericidal effect in the host. Certain capsular types,
for example, K1 and K5, show a molecular mimicry to tissue components,
preventing a proper humoral immune response of the infected host
The LPS is an integral component of the cell wall of Gram-negative bacteria. LPS
is known to activate host response and to induce nitric oxide and cytokine
production
9. Medications
1. E. Coli Meningitis:
• Antibiotics (third generation
Cephalosporin)
2. E. Coli Pneumonia
• Antibiotics (third generation
Cephalosporin’s or
Fluroquinolones)
3. E. Coli Cholecystitis/Cholancitis
• Antibiotics (third generation
Cephalosporin’s that cover E.
Coli and Klebsiella organisms)
4. E. Coli Intra-abdominal Abcess
• Antiobiotics must include
anaerobic coverage
*Campicillin, sulbactam or
Cefoxitin
10. More medications
5. E. Coli Enteric Infection
• Antimicrobial (dexycycline,
trimethoprim/sulfame thoxazole,
fluroquinolones and rifaximan)
6. “Uncomplicated” E. Coli Cystitis
• Fluoroquinolon
• *TMP/SMZ *nitrofurantoin
7. Recurrent E. Coli Cystitis
• Prophylaxis with a fluroquinolone
TMP/SMZ Nitrofurantoin
8. Acute Uncomplicated E. Coli
• Pyelonephritis (in young
Women)
• Fluroquinolone or TMP/SMZ for
14-days
9. E. Coli Perinephric Abscess or
Prostatitis
• Treated at least 6 weeks of
Antibiotics
10. E. Coli Sepsis
• Antibiotics
11. Vaccines
Pathogenic Escherichia coli strains are involved in a diverse
spectrum of diseases, including intestinal and extraintestinal
infections (urinary tract infections and sepsis). The absence of a
broadly protective vaccine against all these E. coli strains is a
major problem for modern society due to high costs to health
care systems
Harmful types of E. coli, such as 0157, put out highly destructive
toxins that poison healthy cells. The infection can kill elderly
people or the very young. Some patients who survive develop
kidney failure or brain damage. Urinary infections and diarrhea
frequently are caused by strains of E. coli.
12. Vaccines
There are currently two E. coli O157 vaccines on the market –
Canada’s Econiche, which blocks the protein that allows E.
coli to colonize in a cow’s gut, and America’s Epitopix SRP,
which prevents the pathogen’s iron uptake. Both are under
limited licensing in the U.S.
Studies have suggested that implementation of an E. coli
vaccine could reduce human illnesses by as much as 83%,
but because cattle are asymptomatic carriers for the
zoonotic disease, ranchers bear the cost of the vaccine
without seeing much direct benefit
13. QUIZ
What is the scientific name for E. Coli?
A.Escherichia coli
B. Eubacterium coli
C.Entophysalis coli
D.Enterococcus coli
23. Sources
Bien, Justyna, Olga Sokolova, and Przemyslaw Bozko. "Role Of Uropathogenic
Escherichia Coli Virulence Factors In Development Of Urinary Tract Infection And
Kidney Damage." International Journal Of Nephrology (2012): 1-15. Academic
Search Complete. Web. 23 Feb. 2014.
Reshes, G., Vanounou, S., Fishov, I., & Feingold, M. (2008). Cell shape dynamics in
escherichia coli. Biophysical Journal, 94(1), 251-64. Retrieved from
http://search.proquest.com/docview/215689801?accountid=11033
Recer, Paul. "Decoding of E. Coli could Lead to Vaccines." Austin American Statesman:
0. Sep 05 1997. ProQuest. Web. 24 Feb. 2014
http://www.foodsafetynews.com/2013/09/e-coli-cattle-vaccination-could-prevent-83-
percent-of-human-cases/#.UwwFFPldWSo
http://www.textbookofbacteriology.net/e.coli.html
