Treatment of Aerococcus urinae in a Dialysis Patient
For a dialysis patient with Aerococcus urinae in urine culture, treat with ampicillin or penicillin, with dosing adjusted for dialysis and administered after each dialysis session. 1, 2
Antibiotic Selection
First-line options:
- Ampicillin/Penicillin: Aerococcus urinae shows 100% susceptibility to these agents, making them preferred first-line treatments 3
- Nitrofurantoin: Effective against A. urinae with clinical and microbiological success rates of 71-76%, but should be avoided in patients with renal failure due to nephrotoxicity 4, 5
- Vancomycin: Alternative for patients with penicillin allergy, with 100% susceptibility reported for Aerococcus species 3
Dosing for dialysis patients:
- Ampicillin: 1-2g after each dialysis session 5
- Penicillin G: Dose after dialysis sessions 5
- Vancomycin: 20 mg/kg loading dose during the last hour of dialysis, then 500 mg during the last 30 minutes of each subsequent dialysis session 5
Treatment Duration and Approach
- For uncomplicated UTI: 10-14 days of systemic antibiotics 5
- For complicated infections or bacteremia: 4-6 weeks of therapy 5
- Consider antibiotic lock therapy as adjunctive treatment if patient has a dialysis catheter 5
Special Considerations for Dialysis Patients
- Avoid nephrotoxic antibiotics such as aminoglycosides which carry substantial risk of irreversible ototoxicity 5
- Cephalosporins are generally preferred over aminoglycosides for gram-negative coverage in dialysis patients, but penicillins are more appropriate for Aerococcus 5
- Antibiotic selection should be based on pharmacokinetic characteristics that permit dosing after each dialysis session 5
Monitoring and Follow-up
- Obtain surveillance blood cultures 1 week after completion of antibiotic course if a catheter has been retained 5
- If blood cultures remain positive, remove the catheter and place a new long-term dialysis catheter after obtaining negative blood cultures 5
- Monitor for clinical response within 2-3 days of initiating therapy 5
Potential Complications
- A. urinae can cause serious infections including bacteremia, endocarditis, and spondylodiscitis in addition to UTI 1, 6
- Patients with urinary catheters or chronic urinary retention are at higher risk for complicated infections 1
- Prompt and culture-specific treatment is critical to avoid clinical progression of the infection 1
Antibiotic Resistance Considerations
- While generally susceptible to penicillins, resistance to ciprofloxacin has been documented in approximately 10.9% of Aerococcus isolates 3
- Due to increasing antibiotic resistance, antibiotic susceptibility testing should guide final treatment selection 1
Remember that Aerococcus urinae is increasingly recognized as a pathogen in elderly patients with multimorbidity and those with urologic conditions 1, 6.