Escherichia coli 0157: H7

AKA- E. Coli (0157: H7)

Greg Jamieson

Classification

• Domain- Eubacteria• Phylum- Proteobacteria• Class- Gammaproteobacteria• Order- Enterobacteriales• Family- Enterobacteriaceae• Genus- Escherichia• Species- E. Coli 0157:H7• - E. Coli 0157:H7 is currently under International Statistical

Classification of Diseases and Related Health Problems 10th Revision for “Certain Infectious and parasitic diseases”

Shape & Structure

• E. Coli 0157: H7 is a serotype of E. Coli, or strain. • It is an enterohemorrhagic strain, meaning it causes

bloody diarrhea and inflammation of the colon.• Gram- Negative, Unicellular, Bacillus (rod shaped)

bacteria.• May have pili that allow it move and attach to human

cells. • 0157:H7 refers to the Cell wall antigen number (O), and

the H refers to the flagella antigen.• Contains divergent plasmids from a common ancestor.

Mode of Nutrition & Effect of Oxygen

• E. Coli 0157: h7 is heterotrophic and cannot make its own food.

• E. Coli 0157: H7 are facultative anaerobes that can survive with or without oxygen, which makes them even more dangerous.

Gram- Stain Negative Bacteria

Transmission

• E. Coli 0157: h7 can infect people through contaminated food and water, or oral contact with contaminated surfaces.

• It is very virulent with a very low infectious dose.• They are found on cattle farms and can be

present in healthy cattle. • The toxins in E. Coli 0157: h7 are highly specific

in their receptors, so some animals can carry the bacteria and be unharmed.

Toxins

• E. Coli 0157: h7 contain “shiga-like” toxins, iron regulated toxins that catalytically inactivate 60S ribosomal subunits of eukaryotic cells, blocking mRNA translation and causing cells to die.

• Only certain strains of E. Coli carry this quality (mutation with a prophage).

Signs & Symptoms

• E. Coli infection can cause violent diarrhea and abdominal cramps. It can also be asymptomatic at times.

• In young children and elderly people, it can cause kidney failure and the destruction of red blood cells.

Diagnosis

• Sample of the infection fermenting on agar plate is one way used to diagnose someone with E. Coli 0157: h7

• Another way is used through stool culture, or detecting the bacteria through the inspection of fecal matter.

Treatment

• Most people recover from E. Coli 0157: h7 in 5- 10 days without an antibiotic or special treatment.

• If found in children or elderly, kidney failure can require blood transfusions and kidney dialysis.

Misc.

• The pathogen results in an estimated 2,100 hospitalizations annually in the United States.

• Illness is often misdiagnosed. • Beef processing is the common point of

contamination; during the slaughtering process.

• E. coli O157:H7 infection is nationally reportable in the USA and Great Britain, and is reportable in most states.

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