What is the initial treatment for a patient diagnosed with Corynebacterium striatum urinary tract infection (UTI)?

Treatment of Corynebacterium striatum Urinary Tract Infection

Vancomycin is the recommended initial treatment for Corynebacterium striatum urinary tract infection due to its consistent susceptibility pattern and low resistance rates. 1

Pathogen Considerations

• C. striatum has emerged as a significant pathogen, particularly in patients with indwelling medical devices, immunocompromised status, and previous antibiotic exposure 2
• Most C. striatum strains are multidrug-resistant, with studies showing susceptibility primarily to vancomycin 1
• Daptomycin should be avoided even when isolates appear susceptible, as high-level resistance can develop rapidly during treatment 3

Treatment Algorithm

First-line therapy:

• Vancomycin IV (15-20 mg/kg every 8-12 hours, adjusted for renal function) 1
  • Target trough levels: 15-20 μg/mL for serious infections
  • Duration: 7-14 days depending on infection severity and clinical response

Alternative options (if vancomycin cannot be used):

• Linezolid 600 mg IV/PO every 12 hours 3
  • Monitor for hematologic toxicity if treatment extends beyond 2 weeks
  • Consider switching to oral therapy when clinically improved

For complicated UTI with C. striatum:

1. Remove or replace urinary catheter if present 4
2. Obtain urine culture and susceptibility testing before initiating therapy
3. Begin empiric therapy with vancomycin while awaiting culture results
4. Adjust therapy based on susceptibility testing results
5. Consider urologic evaluation if symptoms persist despite appropriate therapy

Special Considerations

• Catheter management: Remove or replace indwelling catheters if clinically feasible, as C. striatum infections are frequently associated with indwelling devices 4
• Duration of therapy:
  • Uncomplicated lower UTI: 7 days
  • Complicated or upper UTI: 10-14 days 5
• Follow-up: Obtain follow-up urine culture after completion of therapy to confirm microbiological cure 4

Clinical Pearls and Pitfalls

• Do not dismiss as contaminant: C. striatum was historically considered a contaminant but is now recognized as a potential pathogen, especially in immunocompromised patients 1
• Susceptibility testing is crucial: Due to multidrug resistance, susceptibility testing should be performed on all clinically significant isolates 2
• Watch for treatment failure: Monitor closely for clinical response within 72 hours of initiating therapy; consider alternative agents if no improvement 4
• Risk factors for true infection: Malignancy and neutropenia significantly increase the odds of true C. striatum bloodstream infection versus contamination 1

By following this treatment approach, clinicians can effectively manage C. striatum UTIs while minimizing the risk of treatment failure due to antimicrobial resistance.