Treatment of Achromobacter Infections
For Achromobacter infections, the recommended first-line treatment is piperacillin-tazobactam or a carbapenem (imipenem or meropenem), with trimethoprim-sulfamethoxazole as an alternative for less severe infections. 1, 2
Antimicrobial Selection Based on Infection Severity
Severe Infections (Bacteremia, Pneumonia, Necrotizing Infections)
- First-line therapy: Piperacillin-tazobactam 4.5g IV every 6-8 hours or a carbapenem (imipenem 1g IV every 6-8 hours or meropenem 1g IV every 8 hours) 3, 2
- For critically ill patients, consider combination therapy with an antipseudomonal β-lactam plus an aminoglycoside (despite intrinsic resistance, synergistic effects have been observed) 2
- In cases of suspected polymicrobial infection, broader coverage may be needed (e.g., vancomycin plus piperacillin-tazobactam or a carbapenem) 3
Less Severe Infections (UTIs, Mild Soft Tissue Infections)
- Trimethoprim-sulfamethoxazole (if susceptible) 4
- Piperacillin-tazobactam or a carbapenem for more complicated cases 4
- Ceftazidime may be effective in susceptible isolates 2, 5
Considerations for Specific Clinical Scenarios
Catheter-Related Bloodstream Infections
- Remove infected catheter when possible 6
- If catheter retention is necessary, consider antibiotic lock therapy in addition to systemic antibiotics 6
- Piperacillin-tazobactam or carbapenem therapy for 10-14 days 5
Respiratory Infections (including in Cystic Fibrosis)
- Extended therapy (14-21 days) with piperacillin-tazobactam or a carbapenem 1
- For carbapenem-resistant isolates, consider cefiderocol or eravacycline as salvage therapy 1
Antimicrobial Resistance Patterns
- Achromobacter species are intrinsically resistant to most cephalosporins (except ceftazidime), aztreonam, and aminoglycosides 1
- Increasing carbapenem resistance is being reported, primarily due to efflux pumps and metallo-β-lactamases 1
- Most isolates remain susceptible to:
Treatment Duration
- Uncomplicated infections: 7-10 days 4
- Bacteremia: 10-14 days 5
- Pneumonia or deep-seated infections: 14-21 days 1
Special Considerations
- Obtain cultures before initiating antibiotics whenever possible to guide definitive therapy 3
- Perform susceptibility testing on all isolates due to variable resistance patterns 3, 1
- Consider source control (e.g., drainage of abscesses, removal of infected devices) as a critical component of management 6
- For immunocompromised patients, consider broader initial coverage until susceptibilities are available 5
Common Pitfalls
- Relying on aminoglycosides as monotherapy (high rates of intrinsic resistance) 2
- Using narrow-spectrum cephalosporins or aztreonam (intrinsically resistant) 1
- Failure to identify and address the source of infection, particularly with device-related infections 6
- Inadequate duration of therapy, especially for deep-seated infections 5