Proteus mirabilis

Categorization
Cell Wall: Gram Negative Shape: Rod
Biochemistry: Lactose Fermenter, Indole Negative
Virulence Factors
  • Urease: Although not considered an exotoxin, urease splits urea, liberating ammonium that increases (alkalinizes) the urine pH. Abnormally increased urine pH can lead to precipitation of compounds that increases the risk of renal and urinary tract stones, especially of the "Struvite" subtype.
Culture and Detection
  • P. mirabilis is highly motile and rather than forming distinct colonies on a plate, instead characteristically "swarms" across the entire surface of selective media.
Clinical Consequences
Treatment
  • First Choices: Ampicillin
  • Additional Choices: Bactrim