Management of Nakaseomyces Urinary Tract Infection
For Nakaseomyces (formerly Candida glabrata) with 30-50,000 CFU/mL in urine, treatment depends critically on whether the patient is symptomatic and has risk factors—if asymptomatic, remove the urinary catheter if present and observe without treatment; if symptomatic or high-risk, treat with fluconazole 200 mg daily for 2 weeks after confirming fluconazole susceptibility. 1
Initial Assessment: Colonization vs. True Infection
The colony count of 30-50,000 CFU/mL falls below the traditional threshold of 50,000 CFU/mL used to distinguish true UTI from contamination in catheterized specimens, though this threshold is being reconsidered when coupled with symptoms and pyuria. 1
Key clinical decision points:
- Asymptomatic candiduria almost always represents colonization, not infection, and does not require antifungal therapy in most patients. 1
- Treatment is indicated only if: the patient has urinary symptoms (dysuria, frequency, urgency, suprapubic pain, or flank pain with fever), is a very low birth weight neonate, is neutropenic with fever, or is undergoing urologic instrumentation. 1, 2, 3
- Candiduria does not commonly lead to candidemia, and treatment does not reduce mortality in asymptomatic patients—it serves as a marker of underlying illness severity rather than a cause of death. 1
Non-Pharmacologic Management First
Remove or replace indwelling urinary catheters if present—this alone resolves candiduria in approximately 40-50% of asymptomatic patients without any antifungal therapy. 2, 3, 4, 5
Additional predisposing factors to address include discontinuing unnecessary antibiotics and optimizing diabetes control. 6, 7
Species-Specific Considerations for Nakaseomyces
Nakaseomyces (formerly Candida glabrata) has critical differences from other Candida species:
- Nakaseomyces is frequently fluconazole-resistant or has reduced susceptibility compared to C. albicans. 1
- Obtain species identification and antifungal susceptibility testing before initiating therapy, as treatment selection depends entirely on fluconazole susceptibility. 8, 6
Treatment Algorithm Based on Susceptibility
If Fluconazole-Susceptible:
Oral fluconazole 200 mg (3 mg/kg) daily for 2 weeks is the treatment of choice for symptomatic cystitis. 1, 2, 9
- Fluconazole achieves high urinary concentrations with the oral formulation and is the preferred agent due to safety and efficacy. 4, 5, 10
- For pyelonephritis or upper tract infection, increase to fluconazole 200-400 mg (3-6 mg/kg) daily for 2 weeks. 2
If Fluconazole-Resistant:
For fluconazole-resistant Nakaseomyces, use amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days OR oral flucytosine 25 mg/kg four times daily for 7-10 days. 1, 3
- Amphotericin B deoxycholate is preferred for resistant organisms as it achieves adequate urinary concentrations. 6, 4
- Flucytosine can be used alone or in combination with amphotericin B for synergy, though resistance can develop when used as monotherapy. 3, 8, 5
Critical Pitfalls to Avoid
Do not use echinocandins (caspofungin, micafungin, anidulafungin) for urinary tract infections—they achieve inadequate urinary concentrations and have documented treatment failures. 3, 4, 5
Do not treat asymptomatic candiduria in most patients, as treatment does not improve outcomes and candiduria typically represents colonization. 1
Do not assume fluconazole will be effective for Nakaseomyces without susceptibility testing—this species has high rates of fluconazole resistance. 1, 6
Special High-Risk Populations Requiring Treatment
Even if asymptomatic, treat candiduria in:
- Very low birth weight neonates (use amphotericin B deoxycholate 1 mg/kg daily or fluconazole 12 mg/kg daily if not on fluconazole prophylaxis). 2
- Neutropenic patients with fever, though recent evidence suggests this may not always be necessary. 1
- Patients undergoing urologic instrumentation (treat periprocedure to prevent candidemia). 1, 3
Monitoring and Follow-Up
Obtain follow-up urine cultures to document clearance after completing therapy. 3, 8
If treatment fails despite appropriate therapy, obtain imaging (ultrasound or CT) to identify fungus balls, hydronephrosis, abscesses, or structural abnormalities. 2, 3, 8
Fungus balls require surgical intervention in addition to antifungal therapy for cure. 2
Duration of Therapy
Continue treatment for 2 weeks for uncomplicated symptomatic cystitis, or until symptoms resolve and urine cultures no longer yield Nakaseomyces. 2, 3, 8
For upper tract infections or complicated cases, more prolonged therapy (2-4 weeks) may be necessary. 8