All about E.coli O157:H7, a harmful strain of Coliform

bacteria

Presented by:

Mansoor Jehangir

(for CE599 Seminar)

COLIFORM BACTERIA

Coliform Bacteria are indicator organisms.

Readily found in soil, decaying vegetation, animal feces, and raw surface water.

May be accompanied by pathogens, but do not normally cause diseases.

Most likely to survive in deep, slow moving, heavily polluted waters that lack dissolved oxygen.

COLIFORM BACTERIA Coliform Test:

Total coliform test.

Fecal coliform test.

>Total coliform absent means water is safe to drink

>Total coliform or fecal colifrom present means it s unsafe to drink (super- chlorination is needed).

Will coliform bacteria make us sick?

Maybe, maybe not.

Some strains of E. coli are disease causing and can be fatal at times.

Escherichia (E.coli) E. coli is the abbreviated name of the bacterium in the Family Enterobacteriaceae named Escherichia (Genus) coli (Species).

Widely distributed in the intestine of humans and warm-blooded animals and is the predominant facultative anaerobe in the intestine.

E. coli is a member of the family Enterobacteriaceae, which includes many genera, including known pathogens such as Salmonella, Shigella, and Yersinia.

Escherichia (E.coli)

E. Coli Bacillus anthracis

Shigella sonii

Escherichia (E.coli) Innocuous E.Coli.:

E. coli provide us many necessary vitamins.

Bacteria make the vitamins, and we gladly absorb them.

Suppresses the growth of harmful bacterial species.

Source of Vitamin K and B-complex vitamins.

(we help them to live, and they help us to live)

Escherichia (E.coli)

Harmful strains of E.coli.

Three groups of E coli are associated with diarrheal diseases.

(ETEC) produces enterotoxins (damages the mucosal cells)

(EIEC) cause tissue destruction and inflammation.

(EPEC) enteropathogenic (associated with outbreaks of diarrhea in newborn nurseries).

Escherichia (E.coli) E. coli O157:H7

Member of the EHEC - enterohemorrhagic E. coli group.

Enterohemorrhagic means an intestinally-related organism which causes hemorrhaging - and therefore, loss of blood.

Escherichia (E.coli) Genetic formation of E. coli O157:H7

Cells infected with a bacterial virus.

Ability of virus to insert its DNA into bacteria’s Chromosome.

Division of infected parent cell into daughter cells produced and spread E.coli O157:H7.

Escherichia (E.coli) E. coli O157:H7

What illness does E. coli O157:H7 cause?

Hemorrhagic colitis: Severe cramping (abdominal pain) and diarrhea which is initially watery but becomes grossly bloody.

Occasionally vomiting occurs.

Fever is either low-grade or

absent.

In children under 5 years of

age, red blood cells are

destroyed and the kidneys

fail (hemolytic uremic

syndrome).

Escherichia (E.coli) E. coli O157:H7

How is E. coli O157:H7 spread?

Eating meat, especially ground beef, that has not been cooked sufficiently to kill E.coli.

Consumption of sprouts, lettuce, salami, unpasteurized milk and juice, and swimming in or drinking sewage-contaminated water.

Bacteria in diarrheal stools of infected persons can be passed from one person to another if hygiene or hand washing habits are inadequate.

Escherichia (E.coli) E. coli O157:H7

What can we do to prevent E. coli O157:H7 infection?

Cook all ground beef and hamburger thoroughly (at least 160oF).

Keep raw meat separate from ready-to-eat foods.

Drink only pasteurized milk, juice, or cider.

Wash fruits and vegetables thoroughly.

Avoid alfalfa sprouts until their safety can be assured.

Avoid swallowing lake or pool water while swimming.

Anyone with a diarrheal illness should avoid swimming in public pools or lakes, and preparing food for others.

Thankyou