Proteus Mirabilis

Last updated 06/11/18

Definition

• Gram negative motile bacilli typically associated with complicated urinary tract infections (UTI)

Features

• Aerobic, facultative anaerobe
• Produces urease
• Known for robust swarming motility
• Same bacterial family as Enterobacteriaceae (ie: E. Coli)
• Transmisttion via gastrointestinal tract or potentially person to person

Diseases

• UTI 1-10% of all infections
• Urine pH often >7.2
• Cystitis
• Pyelonephritis: increased incidence
• Urosepsis: up to 50% mortality rate in elderly
• Bacteraemia
• Urolithiasis: struvite stones
• Less commonly
• Respiratory tract infections
• Eye, ear, nose infections
• Otitis externa
• Skin infections
• Burns infections
• Wound infection
• Neonatal meningitis
• Empyema
• Osteomyelitis

Risk Factors

• Elderly
• Diabetes mellitus (DM)
• Indwelling urinary catheter (IDC) or suprapubic catheter (SPC)

Investigations

• Urine MCS
• Blood cultures (BC)

Management

• Typically sensitive to
• Beta lactams: Ceftriaxone
• Aminoglycosides: Gentamicin
• Fluoroquinolones
• Trimethoprim/Sulfamethoxazole (Bactrim)
• Generally resistant to
• Nitrofuranitoin
• Tetracyclines: Doxycycline

---

References

1. Chen C, Chen Y, Lu P, Lin W, Chen T, Lin C. Proteus mirabilis urinary tract infection and bacteraemia: Risk factors, clinical presentation, and outcomes. Journal of Microbiology, Immunology and Infection. 2012;45:228-236.
2. Schaffer J, Pearson M. Proteus mirabilis and Urinary Tract Infections. Microbiol Spectr. 2015;3(5)