What is the recommended treatment for Candida guilliermondii infection?

Treatment of Candida guilliermondii Infection

Echinocandins are the recommended first-line treatment for Candida guilliermondii infections due to consistent susceptibility and the species' well-documented reduced susceptibility to fluconazole. 1, 2

Initial Antifungal Selection

• Start an echinocandin immediately for candidemia or invasive C. guilliermondii infection, using one of the following regimens: 1, 2

  • Caspofungin: 70 mg loading dose, then 50 mg daily
  • Micafungin: 100 mg daily
  • Anidulafungin: 200 mg loading dose, then 100 mg daily
  • Rezafungin (newer option): per approved dosing 1

• Do not use fluconazole as empiric therapy for C. guilliermondii—only 75% of isolates are susceptible, with even lower susceptibility (58-68%) in surgical and dermatology patients. 3 Recent data from 2024 shows 9.8-20.5% of isolates are non-wild type for triazoles. 4

• Lipid formulation amphotericin B (3-5 mg/kg daily) serves as an alternative if echinocandins cannot be used, though C. guilliermondii shows constitutively reduced susceptibility to polyenes. 1, 5, 6

Critical Management Steps

• Remove all central venous catheters as soon as safely possible—this is essential for source control. 1, 2

• Obtain antifungal susceptibility testing immediately on all isolates, as resistance patterns vary significantly and clinical breakpoints for triazoles remain uncertain. 4

• Perform daily or every-other-day blood cultures until clearance is documented—C. guilliermondii can cause prolonged fungemia despite appropriate therapy. 2, 6

• Conduct dilated fundoscopic examination within the first week to detect endophthalmitis, which requires longer therapy and possible surgical intervention. 1, 2

Treatment Duration and De-escalation

• Continue therapy for minimum 14 days AFTER documented bloodstream clearance and resolution of attributable symptoms—not 14 days from initiation. 1, 2

• Consider step-down to fluconazole (400 mg daily) ONLY if: 1, 2

  • Susceptibility testing confirms fluconazole susceptibility (MIC ≤2 μg/mL)
  • Patient is clinically stable
  • Bloodstream has been cleared

• Voriconazole (200 mg twice daily) shows better activity than fluconazole (91% vs 75% susceptible) and may be used for step-down in fluconazole-resistant, voriconazole-susceptible isolates. 3

Special Populations

Neutropenic Patients

• Use echinocandin or lipid formulation amphotericin B as first-line therapy. 1, 2
• Continue treatment until neutropenia resolves in addition to the 14-day post-clearance period. 2
• Catheter removal remains strongly recommended when feasible, though decisions should account for thrombocytopenia and bleeding risk. 2

Neonates

• Amphotericin B deoxycholate (1 mg/kg daily) is recommended as first-line therapy. 2
• Echinocandins should be limited to salvage therapy in this population. 2
• Mandatory lumbar puncture and dilated retinal examination for all neonates with positive cultures. 2

Key Clinical Context

C. guilliermondii represents 1.4% of Candida isolates globally but up to 3.7% in Latin America, making it the sixth most common Candida species. 3 The organism predominantly affects immunocompromised patients (66% in recent series), particularly those with malignancy (68%) and those receiving immunosuppressive therapy (59%). 4, 7

Despite high antifungal resistance rates, mortality is lower than C. albicans (13.6% vs 33.9% at 30 days), likely due to reduced virulence and poor biofilm formation. 7 However, in severely neutropenic patients, mortality can be substantial, with direct attribution to C. guilliermondii in 19% of cases. 4

Critical Pitfalls to Avoid

• Never delay echinocandin therapy while awaiting susceptibility results—all isolates in the largest U.S. series remained susceptible to micafungin. 4

• Do not assume fluconazole will work—even if prior azole prophylaxis wasn't used, inherent reduced susceptibility is common. 3, 5

• Do not discontinue therapy prematurely—prolonged fungemia despite appropriate therapy has been documented, particularly in neutropenic patients. 6

• Do not skip ophthalmologic examination—endophthalmitis changes management significantly and requires extended therapy. 1, 2