Treatment of Enterobacter cloacae UTI
For non-carbapenem-resistant Enterobacter cloacae UTI, use a carbapenem (meropenem or imipenem) or fourth-generation cephalosporin (cefepime) based on susceptibility testing, avoiding third-generation cephalosporins due to high resistance rates. 1
Key Treatment Principles
Avoid Third-Generation Cephalosporins
- First and second-generation cephalosporins are generally not effective against Enterobacter infections 1
- Third-generation cephalosporins should not be used due to increased likelihood of resistance, particularly for E. cloacae and E. aerogenes 1
- E. cloacae possesses inducible AmpC β-lactamases that confer resistance to third-generation cephalosporins even when initial susceptibility testing suggests sensitivity 2
Preferred Agents for Susceptible Strains
Fourth-Generation Cephalosporins:
- Cefepime 0.5-1 g IV every 12 hours for mild-moderate UTI or 2 g IV every 12 hours for severe UTI 3
- Cefepime can be used if Extended-Spectrum beta-lactamase (ESBL) is absent 1
- Duration: 7-10 days 3
Carbapenems (First-Line for Multidrug-Resistant Strains):
- Meropenem and imipenem are effective against E. cloacae and E. aerogenes 1
- Carbapenems represent a valid therapeutic option for multidrug-resistant Enterobacter infections 1
- Recent data shows several isolates remain susceptible to carbapenems (meropenem, imipenem, ertapenem), though emerging resistance is a concern 4
Alternative Oral Agents for Uncomplicated Cystitis
When susceptibility permits:
- Trimethoprim-sulfamethoxazole (if susceptible) 5
- Fluoroquinolones (ciprofloxacin or levofloxacin) if local resistance rates are acceptable 2, 6
- Nitrofurantoin or fosfomycin for simple cystitis 2, 6
Treatment for Carbapenem-Resistant E. cloacae (CRE)
Complicated UTI (cUTI)
Preferred newer agents:
- Ceftazidime-avibactam 2.5 g IV every 8 hours 1
- Meropenem-vaborbactam 4 g IV every 8 hours 1
- Imipenem-cilastatin-relebactam 1.25 g IV every 6 hours 1
- Plazomicin 15 mg/kg IV every 12 hours 1
Simple Cystitis Due to CRE
- Single-dose aminoglycoside (amikacin or gentamicin) 1
- Aminoglycosides achieve urinary concentrations 25- to 100-fold higher than plasma levels, making them ideal for UTI treatment 1
- Meta-analysis of 13,804 patients showed microbiologic cure rates of 87-100% with single-dose aminoglycoside for lower UTI 1
Alternative Options for CRE-UTI
- IV fosfomycin for non-severe cUTI without septic shock 1
- Polymyxins (colistin), tigecycline, or fosfomycin for carbapenem-resistant strains 1
- Avoid tigecycline monotherapy for bloodstream infections 1
Critical Clinical Considerations
Resistance Patterns
- E. cloacae isolates show high resistance to ampicillin, amoxicillin-clavulanate, cephalothin, cefuroxime, and cefoxitin 4
- Historical data shows endemic multi-resistant E. cloacae strains can persist in healthcare settings for years 7
- Dual carbapenemase production (KPC and VIM) has been reported, significantly limiting treatment options 8
Antimicrobial Stewardship
- Always obtain susceptibility testing before finalizing therapy 1
- Reserve newer β-lactam/β-lactamase inhibitor combinations for extensively resistant bacteria 1
- Infectious disease consultation is highly recommended for MDRO infections 1
- Consider prolonged infusion of β-lactams for pathogens with high MIC 1