Overview

  • Inhabitants of the gastrointestinal tract
  • Not pathogenic in the gut
  • Opportunistic infections

Characteristics

  • Non-lactose fermentors
  • Produce hydrogen sulphide
  • Urease positive (differentiate from Salmonella)
  • Highly motile via flagellae
  • May swarm on blood agar
  • Grow on MacConkey agar, producing colourless colonies
  • Produce yellow-green colonies on Brilliant Green agar

Clinical infections

  • Pathogenic strains include Proteus mirabilis and Proteus vulgaris
  • Proteus mirabilits associated with sporadic infections in dogs, cats, cattle, fowl
  • Urinary tract infections in dogs, cats and horses
  • Formation of struvite or apatite stone in the kidney (catalysed by urease)
  • Associated with otitis externa in dogs
  • Wound infections
  • In deep pyoderma

NEVER a pathogen in the gut.