All

• What family do Escherichia, Klebsiella, and Proteus belong to?

  Enterobacteriaceae
• What is the normal habitat of Enterobacteriaceae?

  Normal gut flora of humans and animals

  
• What is a significant characteristic of some Enterobacteriaceae?

  Some are agents of zoonosis

  
• How do Enterobacteriaceae vary in transmission?

  Mode of transmission varies
• What shape are Enterobacteriaceae bacteria?

  Rod shaped
• What type of anaerobes are Enterobacteriaceae?

  Facultative anaerobes
• What is the oxidase status of Enterobacteriaceae?

  Oxidase negative
• Which Enterobacteriaceae are non-capsulated?

  Most, except Klebsiella and some E. coli
• Which Enterobacteriaceae are non-motile?

  Shigella and Klebsiella

  
• What do most Enterobacteriaceae ferment?

  Glucose with acid production
• What do most Enterobacteriaceae reduce nitrate to?

  Nitrite via nitrate reductase
• What is the phylum classification of Enterobacteriaceae?

  Proteobacteria
• How many genera and species are in the Enterobacteriaceae family?

  51 genera and 238 species

  
• What is the appearance of lactose fermenters on MacConkey agar?

  Bright pink colonies

  
• What type of antigen is the lipopolysaccharide O antigen?

  A single organism may carry several O antigens
• What is the function of the K antigen?

  Protects against phagocytosis

  Prevents O agglutination
• What is the flagellar antigen called?

  H antigen

  
• What is a major cause of urinary tract infections?

  Escherichia coli

  
• What are some infections caused by Escherichia coli?

  Gastroenteritis, UTI, meningitis

  
• What indicates pollution in water?

  Detection of E. coli

  
• What is the Gram stain result for Escherichia coli?

  Gram negative rods

  
• What are the virulence factors of Escherichia coli?

  Adhesins

  Surface antigens and toxins

  Fimbriae

  Exotoxins

  
• What is the role of fimbriae in Escherichia coli?

  Attaches to uroepithelial cells
• What does the heat-labile toxin (LT) of ETEC resemble?

  Cholera toxin
• What is the pathogenesis of EAEC?

  Adhere to epithelia in a stacked-brick pattern

  
• What is the mechanism of pathogenesis for EIEC?

  Mucosal invasion and inflammation of large bowel
• What is the clinical feature of Enteropathogenic E. coli (EPEC)?

  Diarrhea with fever in all ages

  
• What is the transmission route for UTI caused by E. coli?

  Ascending infection via urethra

  
• What is the appearance of Klebsiella pneumoniae colonies on MacConkey agar?

  Mucoid and pink colonies

  
• What are the common infections caused by Klebsiella pneumoniae?

  Pneumonia, sepsis, UTI, meningitis
• What is the treatment for Klebsiella pneumoniae infections?

  Based on antibiotic susceptibility tests

  
• What is the treatment for Proteus infections?

  Based on susceptibility testing
• What are the virulence factors of Klebsiella pneumoniae?

  • Capsular K antigen
  • Siderophores
  • Fimbriae
  • Endotoxin (LPS)
  • Outer membrane protein efflux pumps

  
• What is the clinical feature of Proteus infections?

  Urinary tract infections and wound infections

  
• What are the treatment options for Klebsiella pneumoniae infections?

  • Based on antibiotic susceptibility tests
  • Beta-lactam + beta-lactamase inhibitor combination
  • 3rd generation cephalosporins

  
• What are the characteristics of Proteus species?

  • Non-lactose fermenters
  • Urease positive
  • Highly motile
  • Contain O and H antigens
• What are the clinical features of Proteus infections?

  • Urinary tract infections
  • Wound infections
  • Septicemia
  • Ear infections
  • Brain abscesses

  
• What are the laboratory diagnosis methods for Enterobacteriaceae?

  • Gram stain: Gram negative rods
  • Culture: MacConkey, CLED, Blood agar
  • Biochemical tests: IMViC series

  
• What are the treatment options for urinary tract infections caused by Enterobacteriaceae?

  • Trimethoprim-Sulfamethoxazole
  • Nitrofurantoin
  • Based on susceptibility testing

  
• What are the characteristics of Enterobacteriaceae?

  • Gram negative, rod shaped
  • Facultative anaerobes
  • Ferment glucose
  • Most reduce nitrate to nitrite