When 10% ferric chloride is added to phenylalanine deaminase medium inoculated with Proteus mirabilis, the presence of phenylpyruvic acid causes the media to turn dark green.  This is a positive result.

Proteus mirabilisATCC 14153 Growth good to excellent; colonies medium-sized, pale to beige, surrounded by an amber to brown halo; in areas of dense growth, the medium may be completely amber to brown. Swarming is partially to completely inhibited.

Proteus spp. can be naturally resistant to antibiotics, such as benzylepenicillin, oxacillin, tetracycline, and macrolides (137). Proteus spp. can acquire resistance to ampicillin through plasmid mediated beta-lactamases, and chromosomal beta-lactamase expression has now been reported (136).

Deposited Name:Proteus vulgaris Hauser emend. Judicial CommissionProduct Description: Quality control strainMediumATCC® Medium 3: Nutrient agar or nutrient brothGrowth ConditionsTemperature: 37°CAtmosphere: AerobicPropagation Procedure1. Open vial according to enclosed instructions.2. Using a single tube of #3 broth (5 to 6 mL), withdraw approximately 0.5 to 1.0 mL with a Pasteur or1.0 mL pipette. Rehydrate the entire pellet.3. Aseptically transfer this aliquot back into the broth tube. Mix well.4. Use several drops of the suspension to inoculate a #3 agar slant and/or plate.5. Incubate the tubes and plate at 37°C for 24 hours.Colonies on #3 agar are cream, translucent, circular, low convex, entire, and smooth. Swarming occurs withextended incubation. Cells are motile rods in singles and pairs that vary in size

Contact lens wearers are more prone to bacterial infection, especially with Gram-negative organisms. The contact lens induces hypoxia, increases corneal temperature and decreases tear flow over the corneal surface. The adhering 21 of microorganisms (Staphylococci, Moraxella, Candida) to the contact lens and epithelium 22–24 is aided by mucus and proteins. The risk of developing corneal infections is 9–15 times greater with overnight use of contact lenses compared to daytime use. Aphakic eyes are more prone to microbial keratitis with extended wear soft contact lenses. There is a higher risk of bacterial keratitis with disposable contact lenses used overnight.24 The most common organisms associated with contact lens related bacterial keratitis are Pseudomonas aeruginosa and Staphylococci. Bandage soft contact lenses are more often associated with polymicrobial infections (Staphylococci, Streptococci, Serratia). Extended wear soft cosmetic lenses are more prone to Pseudomonas infections.25While Gram-negative organisms like Pseudomonas, Haemophilus and Moraxella cause infectious keratitis in extended wear cosmetic contact lens users, therapeutic soft contact lens wearers on the other hand are prone to corneal ulcers caused by Gram-positive bacteria especially Streptococci.

Mobility No

Pathophysiology

Proteus mirabilis causes 90% of Proteus infections and can be considered a community-acquired infection

species are most commonly found in the human intestinal tract as part of normal human intestinal flora

Selective & Differential Media for Proteus

Proteus mirabilis and Urinary Tract Infections

Proteus mirabilis 24 96 100 100 0 100 96 100(11) 100(11) Proteus vulgaris 2 100 100 100 0 100 100 -- --

Proteus spp. 3 ( 0.9)

AMINOGLYCOSIDESThe aminoglycosides are antibiotics commonly used in ophthalmology. These drugs are poorly absorbed orally and thus are used topically or parenterally. Once absorbed systemically, they are approximately 30% protein bound and are excreted by the urinary system. Patients with impaired renal function must have their parenteral dosage adjusted based on creatinine clearance. These drugs are bacteriocidal, primarily because of their role in the inhibition of protein synthesis and misreading of the genetic code.113 In general they are effective against most Gram-negative organisms (e.g., Pseudomonas, Proteus, Klebsiella, E. coli, Serratia)

actorGrade IGrade IIGrade III LocationNonaxialCentral or peripheralCentral or peripheral Area2 mm2–6 mm6 mm DepthSuperficial one thirdSuperficial two thirdsExtending to inner one third Anterior segment inflammationMildModerate or severe; fibrinous exudateSevere; hypopyon Hospitalization*NoPossiblyPossibly Initial antibiotic therapy†Topical fortified dropsTopical fortified dropsTopical fortified drops    Consider intravenous antibiotics‡

LABORATORY DIAGNOSIS

he Gram-negative rods, however, usually produce a more profuse, wet or soupy appearing infiltrate that is rapidly progressive and spreads to involve the entire cornea

The Proteus organisms are nonfastidious and grow rapidly on almost any medium. They exhibit a characteristic, strong, offensive odor when grown on rich media. When identification is not obvious, the more specific tests, such as the phenylalanine deaminase test (only Proteus is positive for this enzyme), may be used. The urease test is occasionally helpful; however, other bacteria are also capable of producing this enzyme, so it is far less specific. The indole test is helpful to speciate Proteus, because only P. mirabilis does not produce indole.76 The ornithine decarboxylase test also is helpful to separate species: only P. mirabilis and P. morganii are associated with this enzyme.

Proteus spp. can also be found in freshwater, as an indicator of its contamination by feces, even in unexpected habitats.

Proteus mirabilis (0.55%)

KEY BIOCHEMICAL REACTIONS Catalase-positive. Urease-positive. H 2 S-positive. Oxidase-negative. Indole-variable. Methyl-Red-positive. Voges-Proskauer-variable. Lysine-, Arginine Decarboxylase-, and Ornithine-negative. (Only P . mirabilis decarboxylates ornithine). Nitrate is reduced to Nitrite.