II. Definitions
- Proteus
- Genus in the Enterobacteriaceae family
- Facultatively anaerobic Gram-negative rod
- Proteus species are found in animal GI Tract, as well as in manure, soil, and polluted water
- Proteus Mirabilis is the most common human pathogen, and the focus of this page
III. Pathophysiology
- Proteus Mirabilis is a facultatively anaerobic, highly motile Gram-negative rod in Enterobacteriaceae family
- Grouped with EKP Gram Negative Bacteria (Escherichia coli, Klebsiella Pneumoniae, Proteus Mirabilis)
- Colonizes the normal, human Gastrointestinal Tract
- Virulence Factors
- Flagella (H Antigen)
- Highly motile organism
- Swarming motility (rapidly re-distributes to fill a specimen slide)
- Urease activity (urea-splitting)
- Results in an alkaline Urine pH (due to urea metabolism into NH3 and CO2)
- Proteus survival increases in an alkaline environment
- Urease activity is also associated with a higher risk of Pyelonephritis and Struvite Nephrolithiasis
- Polysaccharide capsule
- Cloaks surface Opsonins (immune targets), thereby avoid Phagocytosis by Macrophages
- Lipopolysaccharide (LPS)
- Triggers a severe inflammatory response
- Fimbriae
- Allows organism to adhere to host surfaces and devices (e.g. catheters)
- Flagella (H Antigen)
IV. Associated Conditions
- Urinary Tract Infection (esp. Complicated or hospitalized UTI)
- Struvite Nephrolithiasis
- Wound Infections
- Gastroenteritis
- Nosocomial Infection
V. References
- Gladwin, Trattler and Mahan (2014) Clinical Microbiology, Medmaster, Fl, p.75
- Schaffer (2015) Microbiol Spectr 3(5):10 +PMID: 26542036 [PubMed]
