What is the treatment for Candida krusei (Pichia kudriavzevii) infection in urine with an indwelling catheter that is bypassing?

Treatment of Candida krusei (Pichia kudriavzevii) in Urine with Indwelling Catheter

For Candida krusei urinary tract infection with an indwelling catheter that is bypassing, the treatment should include catheter removal and administration of an echinocandin (caspofungin, micafungin, or anidulafungin) or lipid formulation of amphotericin B due to C. krusei's intrinsic resistance to fluconazole. 1

Initial Management

• Remove the indwelling catheter as soon as possible, as catheter removal is strongly recommended in all cases of Candida infection and has been shown to improve outcomes 1
• If catheter removal is not immediately possible, exchange the catheter over a guidewire and send the catheter tip for culture 1
• Initiate systemic antifungal therapy immediately upon diagnosis, even if symptoms resolve after catheter removal 1

Antifungal Selection for C. krusei

• C. krusei has decreased susceptibility to azoles, particularly fluconazole, requiring alternative therapy 1
• First-line options include:
  • Echinocandins: caspofungin (70 mg IV loading dose, then 50 mg IV daily), micafungin (100 mg IV daily), or anidulafungin (200 mg IV loading dose, then 100 mg IV daily) 1
  • Lipid formulations of amphotericin B (3-5 mg/kg IV daily) 1
• Conventional amphotericin B is effective but associated with more adverse effects 1
• For urinary tract-specific considerations, amphotericin B deoxycholate (0.3-0.6 mg/kg daily for 1-7 days) may be used as it achieves adequate urine concentrations 2, 3

Treatment Duration

• Continue antifungal therapy for 14 days after the first negative blood culture result and resolution of symptoms 4
• Obtain follow-up urine cultures to confirm eradication of infection 2

Special Considerations

• For patients with limited venous access, consider amphotericin B deoxycholate bladder irrigation (50 mg/L sterile water daily for 5 days) as an adjunctive therapy for C. krusei cystitis 2
• If the patient is undergoing urologic procedures, administer systemic antifungal therapy before and after the procedure 2
• For persistent infection despite appropriate therapy, evaluate for fungus balls or other complications requiring surgical intervention 2

Risk Factors to Address

• Eliminate predisposing factors when possible, including:
  • Discontinue unnecessary antibiotics 2, 5
  • Control blood glucose in diabetic patients 3
  • Relieve any urinary obstruction if present 2

Monitoring

• Perform blood cultures to rule out candidemia, especially in high-risk patients 1
• Monitor for clinical improvement within 72 hours of initiating therapy 4
• Consider repeat urine cultures to confirm clearance of infection 4, 2

Pitfalls to Avoid

• Do not use fluconazole for C. krusei infections as this species has intrinsic resistance 1, 3
• Do not use newer azoles (except voriconazole) or echinocandins for isolated urinary tract infections without bloodstream involvement, as they do not achieve adequate urine concentrations 5, 3
• Do not delay catheter removal, as all prospective studies show that catheter retention worsens outcomes 1