Escherichia ColiBy: Katie Johnson & Dana McPeak

What is E. coli?

Large and diverse group of bacteria E. coli bacteria normally live in the intestines of people and

animals Some E. coli are pathogenic, meaning they can cause illness

Signs & Symptoms

E. coli infections typically begin three or four days after exposure to the bacteria (Incubation period)

Symptoms gradually progress over several days Diarrhea, which may range from mild and watery to severe and

bloody Abdominal cramping, pain or tenderness Nausea and vomiting Fever, usually not very high (less than 101 degrees) Infections can range from mild to life threatening Some types of STEC can cause Hemolytic Uremic Syndrome

(HUS- type of kidney failure) 5 to 10 percent of people infected develop HUS

Causes

Contaminated food- infections start when you swallow STEC (Shiga Toxin-Producing E. coli)- the most common foods that are contaminated include:

1. Ground Beef- E. coli bacteria in their intestines can get on the meat

2. Unpasteurized Milk- E. coli bacteria on a cow's udder or on milking equipment can get into raw milk

3. Fresh Produce- runoff from cattle farms can contaminate fields where fresh produce is grown

4. Restaurant meals- cooks or servers who don't wash their hands after using the bathroom can transmit E. coli bacteria to food

Contaminated Water- human and animal feces may pollute ground and surface water, including streams, rivers, lakes and water used to irrigate crops

Causes Continued

- people have also been infected from swimming in lake water and pools that have been infected

Personal Contact- travels from person to person, especially when infected adults and children don't wash their hands properly- outbreaks have also occurred among children visiting petting zoos and animal barns, and even simply from changing diapers

STEC (Shiga Toxin-Producing E. coli)

Bacteria that lives in the guts of ruminant animals including cattle, goats, sheep, deer and elk

Major source of this illness is cattle STEC that cause human illness generally do not make the animals

sick Animals that are infected with this from the environment spread

this illness to humans Shiga toxin belongs to a group of protein toxins

- has a moiety (part) that binds to the cell surface - has a another part that enters the cytosol- inhibits protein synthesis enzymatically - can cause apoptosis (programmed cell death)

Some strains of E. coli can secrete such toxins The bacteria that produce these toxins are the

cause of this illness

Effects on Digestive & Respiratory Systems

Anti-diarrheal medication slows your digestive system down, preventing your body from getting rid of the toxins

E. Coli colonizes the intestinal mucosa where it multiplies and causes damage to the target cells and interferes with the homeostasis that prevails in the GI tract

E. Coli attaches to the microvilli of the intestines via an adhesion molecule known as intimin

If contaminated in the lungs, the patient can experience bacterial pneumonia

Risk factors Age

- young children and older adults are at higher risk of experiencing illness - have more serious complications from the infection

Weak immune systems- usually weakened from AIDS or drugs to treat cancer or to prevent the rejection of organ transplants- more likely to become ill from ingesting E. coli

Eating certain types of foods- these foods include undercooked hamburger, unpasteurized milk, apple juice or cider, and soft cheeses made from raw milk

Diagnosis

Your doctor will send a sample of your stool to a laboratory to test for E. coli

If this test is positive, it must be sent to a public health laboratory for further testing

This testing helps to identify the specific strain because it helps locate the outbreak

Not all STEC infections are diagnosed: - many infected people do not seek medical care- they don’t provide a stool specimen for testing

265,000 STEC infections occur each year in the United States

Treatment

Most people get better between 5 to 7 days Non-specific supportive therapy (hydration) Antibiotics should not be used because they may increase the risk

of HUS Antidiarrheal agents may also increase the risk of HUS and slow

your digestive system down

Prevention

Avoid risky foods-avoid pink hamburger-cook meats at a temperature of at least 160 degrees (use a thermometer)- drink pasteurized milk, juice and cider- wash raw produce thoroughly

Avoid cross-contamination- wash utensils- keep raw foods separate- wash your hands- avoid swallowing water when swimming or playing in lakes, ponds, streams and swimming pools

Recent Outbreaks

Multistate Outbreak of Shiga toxin-producing Escherichia coli O121 Infections Linked to Farm Rich Brand Frozen Food Products: May 10th 2013-35 persons infected with the outbreak strain - reported from 19 states- 82% of ill persons are 21 years of age or younger- 31% of ill persons have been hospitalized - two ill people developed hemolytic uremic syndrome (HUS)- information available to date indicates that consumption of Farm Rich brand frozen food products is one likely source of infection

Recent Outbreaks

Multistate Outbreak of Shiga Toxin-producing Escherichia coli O157:H7 Infections Linked to Organic Spinach and Spring Mix Blend: December 10th 2012- 33 persons infected with the outbreak strain - reported from 5 states- 46% of ill persons were hospitalized- two ill persons developed hemolytic uremic syndrome (HUS)- outbreak was linked to pre-packaged leafy greens produced by State Garden of Chelsea, Massachusetts

Works Cited Page

http://www.mayoclinic.com/health/e-coli/DS01007/DSECTION=risk-factorshttp://www.cdc.gov/ecoli/