Escherichia coli

• What are the key characteristics of E. coli?

  • Gram-negative
  • Rod-shaped (bacillus)
  • Beta-hemolytic
  • Part of normal flora of the colon
• What color does E. coli appear under a gram stain?

  Pink or red
• What does the pool of water in the image symbolize?

  Most strains of E. coli are beta-hemolytic
• What does the green metallic sheen on EMB agar indicate?

  • E. coli produces a green sheen
  • It indicates lactose fermentation
  • EMB agar selects for gram-negative organisms
• What does E. coli produce on EMB agar?

  Green metallic sheen
• What does McConkey agar indicate when it turns pink?

  Organism ferments lactose and produces acid
• What does E. coli look like on McConkey agar?

  Pink color
• How does E. coli compare to other microorganisms in lactose fermentation?

  1. coli ferments lactose faster than others
• What test indicates that E. coli is catalase positive?

  Bubbles in the catalase test
• What does the presence of Dole whip represent in the image?

  1. coli is indole positive
• What does a red color in the indole test indicate?

  1. coli can convert tryptophan into indole
• What is the significance of the type 3 secretion system in E. coli?

  • It is a mechanism for injecting proteins
  • Important for virulence
  • Helps E. coli evade host defenses
• What does spontaneous bacterial peritonitis indicate in E. coli infections?

  Infection of acidic fluid in the abdomen
• What do pili in E. coli help with?

  Associated with UTIs, cystitis, and pyelonephritis
• What do fimbriae in E. coli resemble in the image?

  Long thin wires
• What does the picture of the prostitute represent in the image?

  Inflammation of the prostate (prostatitis)
• What does the military guy represent in the image?

  Amoxicillin treatment for E. coli UTIs
• What does the K antigen in E. coli signify?

  • Present in the polysaccharide capsule
  • Helpful in serotyping
  • Associated with neonatal meningitis
• What do the pregnant women in the image represent?

  Neonates and K antigen association
• What does the cough of the pregnant woman symbolize?

  Pneumonia associated with K antigen
• What does the torch held by the pregnant woman represent?

  1. coli as a torch infection
• What does lipopolysaccharide in E. coli indicate?

  Virulence factor causing septic shock
• What are the components of lipopolysaccharides?

  • O antigen
  • Core
  • Lipid A (most important)
• What is the significance of lipid A in E. coli?

  Activates immune response and causes septic shock
• What are the four strains of E. coli to know for step one?

  1. Enterohemorrhagic E. coli (EHEC)
  2. Enterotoxigenic E. coli (ETEC)
  3. Enteroinvasive E. coli (EIEC)
  4. Diffusely adherent E. coli (DAEC)
• What does the character covered in blood and coal represent?

  Enterohemorrhagic E. coli (EHEC)
• What does EHEC cause?

  Bloody diarrhea
• What is the most common serotype of E. coli in the United States?

  EHEC (O157:H7)
• What is unique about EHEC regarding sorbitol fermentation?

  It does not ferment sorbitol
• How is EHEC often transmitted?

  Undercooked meat and raw leafy vegetables
• What toxin does EHEC produce?

  Shiga-like toxin
• What does the Shiga-like toxin inhibit?

  60S ribosomal subunit
• What are the symptoms of EHEC infection?

  • Bloody diarrhea
  • Abdominal cramps
  • Possible hemolytic uremic syndrome (HUS)
• What are the complications associated with EHEC?

  • Hemolytic uremic syndrome (HUS)
  • Acute kidney failure
  • Thrombocytopenia
• What is the main transmission route for E. coli O157:H7?

  Undercooked meat and raw leafy vegetables
• What does the shirt saying "E. coli O157:H7" signify?

  Another name for E. coli is EHEC
• How does the rock hitting the camera relate to EHEC?

  It symbolizes the shiga-like toxin's effects
• What does the 60 minutes on the camera represent?

  Inhibition of the 60S ribosomal subunit
• What is a key characteristic of E. coli O157:H7 regarding sorbitol?

  It does not ferment sorbitol
• What are the effects of shiga-like toxin from EHEC?

  • Causes hemolytic uremic syndrome
  • Leads to platelet consumption (thrombocytopenia)
  • Results in mechanical hemolysis and anemia
  • Causes microthrombi formation in blood vessels