Escherichia coli is a bacteria that causes many different types of illness.  Strains of E.coli is abundant in the colons of healthy children and adults, however it usually does not cause disease unless the bacteria leaves the colon.  It is one of the most common causes of urinary tract infections.  In young infants, E. coli can cause life-threatening sepsis or meningitis.  Some strains of E. coli can cause severe gastrointestinal illness, sometimes causing severe, bloody diarrhea.  It is the most common cause of "Traveler's diarrhea," and "Montezuma's revenge."  A special strain of E.coli (O157:H7) can cause bloody diarrhea complicated by hemolytic-uremic syndrome (HUS).  HUS can cause destruction of red blood cells, consumption of platelets, and acute kidney failure.

 

Diseases

• Urinary tract, diarrhea (aka - Montezuma's revenge), sepsis, neonatal meningitis

Habitat & Transmission

• Found in the colons of normal, healthy adults. 
• Spread from person to person by dirty hands.

Weapons/Defenses

• There are many different types of E. coli. 
• Some are harmless while others are very dangerous. 
• Capsule - protects against phagocytosis.
• Pili - attach to the walls of the small intestines. 
• Poisons - damage cells of the intestinal walls and cause diarrhea. 
• Some strains can destroy RBC's.

Weaknesses

• All but the most dangerous strains are suceptable to antibiotics.
  

Photo - Under a magnification of 7075x, this colorized scanning electron micrograph (SEM) depicted a number of Gram-negative Escherichia coli bacteria of the strain O157:H7. E. coli O157:H7 is one of hundreds of strains of this bacterium. Although most strains are harmless, and live in the intestines of healthy humans and animals, this strain produces a powerful toxin, which can cause severe illness. CDC/ National Escherichia, Shigella, Vibrio Reference Unit at CDC.  Janice Haney Carr.  2006. Used with permission.