Proteus mirabilis

Proteus mirabilis

Overview

Proteus mirabilis is a Gram-negative, facultatively anaerobic bacterium known for its swarming motility and urease activity. It is part of the normal flora of the human gastrointestinal tract but can cause urinary tract infections (UTIs) and other opportunistic infections. This organism is notable for its ability to rapidly spread across solid surfaces, forming distinctive concentric rings.

Classification

• Kingdom: Bacteria
• Phylum: Proteobacteria
• Class: Gamma Proteobacteria
• Order: Enterobacterales
• Family: Enterobacteriaceae
• Genus: Proteus
• Species: P. mirabilis

Characteristics

P. mirabilis exhibits several distinctive traits:

• Swarming Motility: Ability to move in a coordinated manner on solid surfaces.
• Urease Production: Enzymatic conversion of urea into ammonia and carbon dioxide, increasing the pH of its environment.
• Gram-Negative: Characterized by a thin peptidoglycan layer and an outer membrane containing lipopolysaccharides.

Swarming motility pattern of Proteus mirabilis on an agar plate.

Pathogenicity

While P. mirabilis is a common part of the gut flora, it can cause infections when it enters sterile areas of the body. It is a significant cause of UTIs, particularly in catheterized patients. Other infections include:

• Kidney stones: Due to urease activity, leading to alkaline urine and the formation of struvite stones.
• Wound infections
• Respiratory tract infections

Diagnosis

Diagnosis of P. mirabilis infections involves:

• Urine or blood cultures
• Identification of characteristic swarming on agar plates
• Urease tests
• Gram staining

Treatment

Treatment typically involves antibiotics, though P. mirabilis shows resistance to many common antibiotics. Options include:

• Nitrofurantoin
• Fluoroquinolones
• Third-generation cephalosporins
• Prevention of UTIs involves proper catheter care and hygiene practices.

Research and Epidemiology

Research on P. mirabilis focuses on understanding its resistance mechanisms, developing new antibiotics, and preventing infections in hospital settings. Epidemiological studies track its prevalence in healthcare facilities and the community.

See Also

• Urinary tract infection
• Antibiotic resistance
• Gram-negative bacteria
• Urease

References

• National Center for Biotechnology Information (NCBI)
• Centers for Disease Control and Prevention (CDC)

External Links

• MicrobeWiki - Proteus mirabilis