Sensitive Antibiotics for Enterobacter cloacae Infections
For Enterobacter cloacae infections, carbapenems such as meropenem are the most reliable first-line agents due to their broad spectrum of activity and low resistance rates. 1
First-Line Treatment Options
- Carbapenems (meropenem, imipenem-cilastatin, doripenem) are the preferred first-line agents for serious Enterobacter cloacae complex infections due to their reliable activity and low resistance rates 1
- Fluoroquinolones (levofloxacin, ciprofloxacin) are effective options when the isolate is confirmed to be susceptible 2, 3
- Piperacillin-tazobactam may be used for mild to moderate infections, though it has higher risk of treatment failure with AmpC-producing strains 4
Treatment Based on Infection Site
Intra-abdominal Infections
- For mild to moderate intra-abdominal infections: ciprofloxacin plus metronidazole or levofloxacin plus metronidazole are recommended second-line options 4
- For severe intra-abdominal infections: meropenem or piperacillin-tazobactam are preferred 4
Urinary Tract Infections
- Levofloxacin is FDA-approved for complicated UTIs due to Enterobacter cloacae with a 10-day treatment regimen 2
- Ciprofloxacin is also effective for UTIs caused by susceptible E. cloacae strains 3
Bloodstream and Serious Infections
- Carbapenems remain the most reliable option for bloodstream infections 1
- For carbapenem-resistant strains, combination therapy may be necessary (e.g., polymyxin B plus tigecycline) 5
Important Considerations
Resistance Concerns
- Enterobacter cloacae can rapidly develop resistance to third-generation cephalosporins during therapy due to AmpC beta-lactamase induction 1, 6
- Ceftazidime, ceftriaxone, and cefamandole select for resistance at a faster rate than other beta-lactams 6
- Imipenem has shown the lowest potential for selecting resistance in laboratory studies 6
Combination Therapy
- For bone and joint infections, a fluoroquinolone-cotrimoxazole combination has shown 80% cure rates in retrospective studies 7
- For extensively drug-resistant strains, polymyxin B plus tigecycline has demonstrated synergistic bactericidal activity 5
Common Pitfalls and Caveats
- Avoid third-generation cephalosporins as monotherapy due to high risk of treatment failure and resistance development, even if initially susceptible in vitro 1, 6
- Ampicillin-sulbactam is not recommended for empiric treatment of infections that may involve E. cloacae due to high rates of resistance 4
- When treating neonatal E. cloacae septicemia, ciprofloxacin (10 mg/kg/day) has been used successfully without development of resistance 8
Treatment Duration
- For complicated intra-abdominal infections: 5-14 days 4, 1
- For complicated UTIs: 10 days for levofloxacin per FDA approval 2
- For bone and joint infections: 8-12 weeks of fluoroquinolone-cotrimoxazole combination has shown good results 7