What is the recommended treatment for a urinary tract infection (UTI) caused by Proteus mirabilis?

From the Guidelines

The recommended treatment for a urinary tract infection (UTI) caused by Proteus mirabilis is an intravenous third-generation cephalosporin as empirical treatment for complicated UTI with systemic symptoms, as suggested by the European Association of Urology guidelines 1.

Treatment Options

• For uncomplicated cases, antibiotics such as trimethoprim-sulfamethoxazole (Bactrim DS) 160/800 mg twice daily for 3-5 days may be considered.
• For more severe or complicated infections, extended-spectrum penicillins (piperacillin-tazobactam) or carbapenems may be necessary, often administered intravenously in a hospital setting.
• Fluoroquinolones like ciprofloxacin should only be used if the local resistance rate is <10% and the patient does not require hospitalization 1.

Important Considerations

• Proteus mirabilis produces urease, which raises urine pH and can lead to kidney stone formation, making proper antibiotic selection crucial.
• Patients should complete the entire course of antibiotics even if symptoms improve, drink plenty of water to help flush bacteria from the urinary system, and seek follow-up testing to confirm the infection has cleared completely.
• Recurrent infections may require further investigation to identify underlying structural abnormalities or chronic conditions.

Guideline Recommendations

• The European Association of Urology guidelines recommend managing any urological abnormality and/or underlying complicating factors 1.
• A combination of amoxicillin plus an aminoglycoside or a second-generation cephalosporin plus an aminoglycoside may be considered for complicated UTIs 1.

From the FDA Drug Label

URINARY TRACT INFECTIONS (complicated and uncomplicated) Caused by Escherichia coli, Proteus mirabilis, Proteus vulgaris, Morganella morganii or Klebsiella pneumoniae Urinary Tract Infections For the treatment of urinary tract infections due to susceptible strains of the following organisms: Escherichia coli, Klebsiella species, Enterobacter species, Morganella morganii, Proteus mirabilis and Proteus vulgaris

The recommended treatment for a urinary tract infection (UTI) caused by Proteus mirabilis includes:

• Ceftriaxone (IV), as it is indicated for the treatment of urinary tract infections caused by Proteus mirabilis 2
• Trimethoprim-sulfamethoxazole (PO), as it is also indicated for the treatment of urinary tract infections caused by Proteus mirabilis 3 Key points:
• The choice of antibiotic should be based on susceptibility testing and local epidemiology
• It is essential to consider the potential for drug-resistant bacteria and to use antibacterial agents only when necessary 2, 3

From the Research

Treatment of UTI caused by Proteus mirabilis

• The recommended treatment for a urinary tract infection (UTI) caused by Proteus mirabilis is not explicitly stated in the provided studies, but it can be inferred that antibiotic treatment is necessary 4.
• The study published in 2004 found that most P. mirabilis strains were resistant to several antibiotics, but the least resistance was observed to imipenem and aztreonam 4.
• Another study published in 2021 discussed the development of a vaccine against P. mirabilis, which could be a promising method for preventing UTIs caused by this bacterium 5.
• However, for current treatment, antibiotics such as imipenem and aztreonam may be considered, but the choice of antibiotic should be based on the results of antibiotic susceptibility testing 4.

Prevention of UTI caused by Proteus mirabilis

• To prevent UTIs caused by P. mirabilis, especially in patients with indwelling urinary catheters, antibiofilm-impregnated catheters may be effective in reducing colonization and swarming motility of the bacterium 6.
• The use of antibiofilm compounds such as linalool and 2-hydroxy-4-methoxy benzaldehyde may also be considered to prevent P. mirabilis biofilm formation on urinary catheters 6.

Risk Factors for Bacteremic UTI

• Certain risk factors, such as community-acquired infection, hydronephrosis, band neutrophils accounting for >10% of the white blood cell count, hyperthermia or hypothermia, and a high level of C-reactive protein, have been identified as independent risk factors for P. mirabilis bacteremic UTI 7.
• Clinicians should carefully manage cases that present with these risk factors to prevent bacteremic UTIs and associated complications 7.