Escherichia coli O157:H7

The specific Escherichia coli serotype O157:H7 is an aerobic bacteria that produces a Shiga toxin. This bacteria grows slowly at refrigeration temperatures. E. coli O157:H7 has been shown to survive in acidic food products such as apple cider and mayonnaise.

Sources of the organism:

• Intestinal tracts of some mammals
• Unchlorinated or contaminated water

Associated foods:

• Ground beef
• Raw milk
• Unpasteurized apple cider or juice
• Uncooked fruits and vegetables

Microorganism Characteristics: Gram negative toxin forming aerobic bacteria

The Disease: Hemorrhagic colitis is the name of the disease caused by E. coli O157:H7. A possible complication is hemolytic uremic syndrome (HUS), a urinary tract infection that is a leading cause of acute kidney failure in children.

Symptoms include:

• Severe abdominal cramps
• Bloody diarrhea
• Nausea
• Vomiting
• Low-grade fever

Onset time:

• Symptoms usually begin 3 to 4 days after exposure, but the time may range from 1 to 9 days.

Infective Dose:

• Small numbers (10- 100 cells) of viable E.coli O157:H7 cells need to be consumed for symptoms of the illness to develop.

Duration of symptoms:

• 2-9 days
  

Prevention:

• Thoroughly cook ground beef products (155°F for 15 seconds or 160°F).
• Follow proper hand washing techniques when handling raw ground beef.
• Drink pasteurized milk and juices.
• Reheat leftover foods to 165°F.
• Clean and sanitize food contact surfaces and utensils.
• Refrigerate foods at 41°F or below.

Source of photo: Agricultural Research Service, United States Department of Agriculture (USDA)