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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