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Proteeae Infections


Larry M. Bush

, MD, FACP, Charles E. Schmidt College of Medicine, Florida Atlantic University;

Maria T. Vazquez-Pertejo

, MD, FACP, Wellington Regional Medical Center

Reviewed/Revised Apr 2022 | Modified Sep 2022

The Proteeae are normal fecal flora that often cause infection in patients whose normal flora have been disturbed by antibiotic therapy.

The Proteeae constitute at least 3 genera of gram-negative organisms:

  • Proteus: P. mirabilis, P. vulgaris, and P. myxofaciens

  • Morganella: M. morganii

  • Providencia: P. rettgeri, P. alcalifaciens, and P. stuartii

However, P. mirabilis causes most human infections. These organisms are normal fecal flora and are present in soil and water. They are often present in superficial wounds, draining ears, and sputum, particularly in patients whose normal flora has been eradicated by antibiotic therapy. They may cause bacteremia and deep-seated infections, particularly in the ears and mastoid sinuses, peritoneal cavity, and urinary tract of patients with chronic urinary tract infections or with renal or bladder stones; Proteus organisms produce urease, which hydrolyzes urea, leading to alkaline urine and the formation of struvite (magnesium ammonium phosphate) stones.

P. mirabilis is often sensitive to ampicillin, carbenicillin, ticarcillin, piperacillin, cephalosporins, fluoroquinolones, and aminoglycosides but is resistant to tetracyclines and nitrofurantoin. Multidrug-resistant P. mirabilis is an emerging problem.

Indole-positive species (P. vulgaris, M. morganii, P. rettgeri) tend to be more resistant but generally are sensitive to fluoroquinolones, carbapenems, piperacillin/tazobactam, 3rd-generation cephalosporins, and cefixime.

Drugs Mentioned In This Article

Drug Name Select Trade
Aluvea , BP-50% Urea , BP-K50, Carmol, CEM-Urea, Cerovel, DermacinRx Urea, Epimide-50, Gord Urea, Gordons Urea, Hydro 35 , Hydro 40, Kerafoam, Kerafoam 42, Keralac, Keralac Nailstik, Keratol, Keratol Plus, Kerol, Kerol AD, Kerol ZX, Latrix, Mectalyte, Nutraplus, RE Urea 40, RE Urea 50 , Rea Lo, Remeven, RE-U40, RYNODERM , U40, U-Kera, Ultra Mide 25, Ultralytic-2, Umecta, Umecta Nail Film, URALISS, Uramaxin , Uramaxin GT, Urea, Ureacin-10, Ureacin-20, Urealac , Ureaphil, Uredeb, URE-K , Uremez-40, Ure-Na, Uresol, Utopic, Vanamide, Xurea, X-VIATE
Furadantin, Macrobid, Macrodantin, Urotoin
Zosyn, Zosyn Powder
NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
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