What is the appropriate management of Candida glabrata isolated from a urine culture?

Management of Candida glabrata in Urine Culture

The appropriate management of Candida glabrata isolated from urine depends critically on whether the patient is symptomatic or belongs to a high-risk group; asymptomatic candiduria in most patients should NOT be treated, while symptomatic infection requires fluconazole (if susceptible) or amphotericin B deoxycholate, always combined with removal of indwelling catheters and relief of urinary obstruction. 1

Step 1: Determine if Treatment is Indicated

Do NOT treat asymptomatic candiduria unless the patient meets high-risk criteria 1:

• Neutropenic patients
• Very low birth weight infants (<1500 g)
• Patients undergoing urologic procedures within days
• Presence of urinary tract obstruction requiring intervention

DO treat if any of the following are present 1:

• Symptomatic infection (dysuria, frequency, urgency, fever, flank pain)
• Any of the high-risk groups listed above
• Clinical signs of sepsis or systemic infection

Step 2: Remove Predisposing Factors (Mandatory)

Immediately remove indwelling bladder catheters if present—this is strongly recommended and failure to do so leads to treatment failure and recurrence 1

Eliminate urinary tract obstruction through surgical consultation if hydronephrosis, stones, or strictures are identified 1

Remove or replace nephrostomy tubes/stents when feasible 1

Step 3: Obtain Antifungal Susceptibility Testing

Susceptibility testing is strongly recommended for all clinically relevant Candida isolates, particularly C. glabrata, because this species has reduced susceptibility to fluconazole and can develop resistance 1

C. glabrata exhibits dose-dependent susceptibility to fluconazole, meaning higher doses may be effective for susceptible isolates, but many isolates are resistant 1

Step 4: Select Antifungal Therapy Based on Site and Susceptibility

For Cystitis (Lower Urinary Tract Infection)

If fluconazole-susceptible:

• Oral fluconazole 200 mg (3 mg/kg) daily for 2 weeks 1

If fluconazole-resistant C. glabrata:

• Amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days 1
• Alternative: Oral flucytosine 25 mg/kg four times daily for 7–10 days 1
• Bladder irrigation option: Amphotericin B deoxycholate 50 mg/L sterile water daily for 5 days (useful when systemic therapy contraindicated, but high recurrence rate) 1

For Pyelonephritis (Upper Urinary Tract Infection)

If fluconazole-susceptible:

• Oral fluconazole 200–400 mg (3–6 mg/kg) daily for 2 weeks 1

If fluconazole-resistant C. glabrata:

• Amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days, with or without oral flucytosine 25 mg/kg four times daily 1
• Alternative monotherapy: Oral flucytosine 25 mg/kg four times daily for 2 weeks (weaker recommendation) 1

Step 5: Address Special Situations

Fungal Bezoars or Fungus Balls

Surgical or endoscopic removal is mandatory—antifungal therapy alone is insufficient 1, 2, 3

Combine surgical intervention with systemic amphotericin B as outlined above 2, 3

Consider amphotericin B irrigation through nephrostomy tubes (25–50 mg diluted in 200–500 mL sterile water) if tubes are in place 2, 3

Patients Undergoing Urologic Procedures

Treat prophylactically with oral fluconazole 400 mg (6 mg/kg) daily OR amphotericin B deoxycholate 0.3–0.6 mg/kg daily for several days before and after the procedure 1

Critical Pitfalls and Caveats

Do NOT use echinocandins (caspofungin, micafungin, anidulafungin) for urinary tract infections—they achieve minimal urinary concentrations and are ineffective despite some anecdotal case reports 1, 4, 5, 6

Do NOT use lipid formulations of amphotericin B (liposomal amphotericin, amphotericin B lipid complex) for UTIs—they do not achieve adequate urine levels 4

Do NOT use voriconazole or other azoles besides fluconazole—they are poorly excreted in urine 4

Do NOT continue therapy without removing catheters—this is the most common cause of treatment failure 1

Do NOT treat asymptomatic candiduria routinely—it does not improve outcomes and promotes resistance 1

Monitoring and Follow-Up

Obtain repeat urine cultures to document clearance of infection 1

Monitor renal function and electrolytes (potassium, magnesium) at least twice weekly when using amphotericin B deoxycholate due to nephrotoxicity 7

Pre-hydrate with normal saline before amphotericin B administration to mitigate nephrotoxicity 7

Continue therapy for 2 weeks total after symptoms resolve and cultures clear 1

Emerging Resistance Concerns

C. glabrata is designated a high-priority pathogen by the WHO due to low inherent azole susceptibility, and approximately 10% of clinical isolates demonstrate co-resistance to both azoles and echinocandins 8

The increasing prevalence of C. glabrata in candiduria cases (showing an upward trend compared to C. albicans) makes susceptibility testing even more critical 9