What is the recommended oral antibiotic regimen for treating urinary Enterobacter (E.) cloacae infection?

Treatment of Urinary Enterobacter cloacae Infection

For urinary tract infections caused by Enterobacter cloacae, levofloxacin 500 mg once daily for 10 days is the recommended oral antibiotic regimen based on FDA approval and clinical guidelines. 1, 2

First-Line Treatment Options

Levofloxacin is specifically FDA-approved for complicated urinary tract infections due to Enterobacter cloacae with a recommended dosage of:

• 500 mg once daily for 10 days 1

This recommendation is supported by:

• FDA labeling that explicitly includes E. cloacae in the indications for levofloxacin in complicated UTIs 1
• European Association of Urology and Infectious Diseases Society of America guidelines that recommend fluoroquinolones for complicated UTIs 2

Alternative Options

If fluoroquinolones cannot be used (due to allergies, contraindications, or resistance):

1. Trimethoprim-sulfamethoxazole: 160/800 mg twice daily for 7-14 days (if susceptibility confirmed) 2

2. Third-generation cephalosporins: May require initial IV therapy followed by oral step-down therapy based on susceptibility testing 2

Treatment Duration

• Complicated UTI: 7-14 days of therapy is recommended 2
• Uncomplicated UTI: 5-7 days of therapy (if E. cloacae is causing an uncomplicated infection, which is less common) 2

Important Considerations

Resistance Concerns

• Always obtain urine culture before starting therapy for suspected UTI, especially with Enterobacter species which may have intrinsic resistance mechanisms 2
• Adjust therapy based on culture and susceptibility results 2

Fluoroquinolone Warnings

• The CDC advises that fluoroquinolones should be avoided for uncomplicated UTIs due to increasing resistance and risk of serious adverse effects 2
• FDA warns of serious safety issues affecting tendons, muscles, joints, nerves, and central nervous system associated with fluoroquinolones 2
• However, for E. cloacae UTIs, fluoroquinolones remain a first-line option due to their efficacy against this organism and excellent urinary penetration 2, 3

Monitoring and Follow-up

• Follow-up urine culture 1-2 weeks after completing therapy is recommended if symptoms persist 2
• If bacteriuria recurs after treatment, select an alternative agent rather than repeating the same antibiotic 2

Special Situations

Multidrug-Resistant E. cloacae

• Infectious disease consultation is highly recommended for managing infections caused by multidrug-resistant organisms 2
• Fosfomycin may be considered for MDR UTIs due to its efficacy against resistant organisms, though clinical data specifically for E. cloacae is limited 2

Catheter-Associated UTI

• If patient has an indwelling catheter, replace it before starting antimicrobial therapy if it has been in place for ≥2 weeks 2
• Treatment duration should be 7 days for catheter-associated UTIs with prompt symptom resolution, and 10-14 days for delayed response 2

By following these evidence-based recommendations, clinicians can effectively treat urinary tract infections caused by Enterobacter cloacae while minimizing the risk of treatment failure and antimicrobial resistance.