Treatment of Infections Caused by Enterobacter cloacae Complex

First-Line Treatment Options

• For infections caused by Enterobacter cloacae complex with carbapenem resistance, the International Journal of Antimicrobial Agents recommends ceftazidime/avibactam or meropenem/vaborbactam as first-line treatment options, with the choice depending on the specific resistance mechanism 1, 2

Treatment Algorithm Based on Resistance Pattern

• For KPC-producing Enterobacter cloacae complex, the first-line options are ceftazidime/avibactam 2.5g IV q8h infused over 2-3 hours or meropenem/vaborbactam 4g IV q8h infused over 3 hours 2, 3
• For OXA-48-like producing Enterobacter cloacae complex, the first-line option is ceftazidime/avibactam 2.5g IV q8h 4, 6
• For MBL-producing (NDM, VIM, IMP) Enterobacter cloacae complex, the first-line option is ceftazidime/avibactam plus aztreonam 4

Important Clinical Considerations

• Rapid testing to identify specific carbapenemase type is crucial for guiding appropriate therapy, as recommended by the International Journal of Antimicrobial Agents 7, 8
• Local epidemiology and resistance patterns should be considered when selecting therapy, according to the International Journal of Antimicrobial Agents 2
• The site of infection may influence drug selection, with meropenem/vaborbactam preferred for pneumonia due to better lung penetration 2

Dosing Considerations

• The dosing of meropenem/vaborbactam is 4g IV q8h over 3 hours, as recommended by the Journal of Microbiology, Immunology and Infection 3

Treatment Outcomes and Mortality

• Meropenem/vaborbactam monotherapy for CRE infections has shown higher clinical cure rates and decreased mortality compared to best available therapy, according to the International Journal of Antimicrobial Agents 2
• Ceftazidime/avibactam has demonstrated favorable outcomes in observational studies of KPC-producing Enterobacteriaceae infections, as reported by the International Journal of Antimicrobial Agents 2

Pitfalls to Avoid

• The World Journal of Emergency Surgery recommends avoiding the use of first and second-generation cephalosporins against Enterobacter infections due to intrinsic resistance 9
• The World Journal of Emergency Surgery also recommends avoiding third-generation cephalosporins due to high likelihood of resistance development during therapy, particularly for E. cloacae 9
• The Journal of Microbiology, Immunology and Infection advises against relying on tigecycline monotherapy for bloodstream infections due to low serum concentrations 3
• The International Journal of Antimicrobial Agents recommends avoiding delaying appropriate therapy, as time to active antibiotic therapy influences outcomes in critically ill patients with bloodstream infections 7