How should a urine culture growing Candida species and Lactobacillus be interpreted and managed, considering the patient’s symptoms and risk factors such as indwelling catheter, recent broad‑spectrum antibiotics, diabetes, or immunosuppression?

Management of Urine Culture Growing Candida and Lactobacillus

Interpretation of Culture Results

In most cases, the presence of Candida species in urine represents benign colonization rather than true infection, and the co-isolation of Lactobacillus (a common urogenital commensal) strongly suggests specimen contamination or colonization rather than invasive disease. 1

• Lactobacillus is a normal component of the urogenital flora and its presence typically indicates either contamination during collection or colonization of the lower urinary tract. 1
• Candida in urine is a nonspecific finding that can represent contamination, catheter colonization, bladder colonization, symptomatic cystitis, or upper tract infection. 2
• The combination of both organisms makes true infection less likely unless the patient has clear urinary symptoms (dysuria, frequency, urgency, flank pain, fever). 1

Risk Stratification: Who Requires Treatment?

Asymptomatic Patients (No Treatment Required)

The vast majority of asymptomatic patients with candiduria do not require antifungal therapy, as treatment does not reduce mortality or improve outcomes. 1

• Asymptomatic candiduria almost always represents colonization and treating it provides no clinical benefit. 1, 3
• Candiduria progresses to candidemia in less than 5% of cases. 4, 1
• Treatment does not change mortality rates in asymptomatic patients. 1, 3

High-Risk Asymptomatic Patients (Treatment Mandatory)

Despite lack of symptoms, the following groups require aggressive antifungal treatment: 1

• Neutropenic patients with persistent unexplained fever and candiduria (risk of disseminated candidiasis). 1
• Very low birth weight neonates (<1500 g) due to high propensity for invasive candidiasis. 1
• Patients undergoing urologic procedures or instrumentation within several days (high risk of procedure-related candidemia). 1
• Patients with urinary tract obstruction that cannot be promptly relieved. 1

Symptomatic Patients (Treatment Required)

All patients with urinary symptoms (dysuria, frequency, urgency, flank pain, fever) and Candida in urine require antifungal treatment. 1

First-Line Management: Non-Pharmacologic Interventions

Immediate removal of any indwelling urinary catheter is the single most important intervention, resolving candiduria in approximately 50% of cases without antifungal therapy. 1, 2

• Catheter removal should be attempted before initiating antifungals in asymptomatic patients. 1
• Discontinue unnecessary broad-spectrum antibiotics, as they are a major risk factor for candiduria. 1
• Eliminate urinary tract obstruction if present. 1
• Remove or replace nephrostomy tubes or ureteral stents when feasible. 1

Pharmacologic Treatment Regimens

Symptomatic Candida Cystitis (Lower UTI)

Fluconazole 200 mg (≈3 mg/kg) orally once daily for 14 days is the preferred first-line regimen for fluconazole-susceptible Candida species. 1

• This recommendation is based on randomized controlled trial data demonstrating efficacy. 1
• Fluconazole achieves high urinary concentrations of active drug, ensuring effective pathogen eradication. 1, 2

Symptomatic Candida Pyelonephritis (Upper UTI)

For fluconazole-susceptible organisms, fluconazole 200–400 mg (≈3–6 mg/kg) orally once daily for 14 days is recommended; use the higher 400 mg dose when upper-tract involvement is confirmed. 1

• Development of flank pain, fever >38.3°C, or systemic manifestations should raise suspicion for pyelonephritis. 1

Fluconazole-Resistant Species

For Candida glabrata (often fluconazole-resistant): 1

• 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
• Oral flucytosine monotherapy (25 mg/kg qid for 7–10 days) may be considered when amphotericin B is unsuitable. 1

For Candida krusei (intrinsically fluconazole-resistant): 1

• Amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days is the treatment of choice. 1

Preoperative Prophylaxis for Urologic Procedures

For patients undergoing urologic procedures with candiduria, fluconazole 200–400 mg daily should be administered for several days before and after the procedure. 1

Species-Specific Considerations

• Candida albicans is usually fluconazole-susceptible and is the most frequently isolated urinary Candida species. 1
• Candida glabrata often exhibits fluconazole resistance and requires alternative antifungal agents when treatment is indicated. 1, 3
• Candida krusei is intrinsically fluconazole-resistant. 1

Critical Pitfalls to Avoid

Do not prescribe antifungal therapy for asymptomatic candiduria in otherwise healthy individuals (including diabetic or elderly patients), as it provides no clinical benefit. 1, 3

• Diabetes or advanced age alone does not mandate treatment in asymptomatic patients. 1, 3
• Colony counts and pyuria are unreliable markers for distinguishing colonization from infection, especially in catheterized patients. 1, 5

Avoid using echinocandins (caspofungin, micafungin, anidulafungin) or newer azoles (voriconazole, posaconazole) for urinary Candida infections, as these drugs achieve inadequate urine concentrations. 1, 2

Lipid formulations of amphotericin B should not be used for Candida urinary tract infections because they do not attain adequate urinary levels. 1

In male patients, candiduria should not be automatically dismissed as simple colonization; evaluate for possible prostatitis if urinary symptoms develop. 1

Evaluation for Complications

If urinary symptoms persist beyond 48–72 hours, obtain renal or bladder ultrasound (or CT) to exclude obstruction, fungal balls, or perinephric abscesses. 1

• Presence of fungal balls or casts in the renal pelvis or bladder mandates surgical intervention in addition to systemic antifungal therapy. 1
• Adjunctive irrigation through nephrostomy tubes with amphotericin B deoxycholate 25–50 mg diluted in 200–500 mL sterile water may be used as a complement to systemic treatment. 1

Context-Specific Management Algorithm

For patients with indwelling catheters: 1

1. Remove catheter immediately if feasible
2. Observe for 48–72 hours
3. If candiduria persists and patient is symptomatic, treat with fluconazole

For patients on broad-spectrum antibiotics: 4, 1

1. Discontinue unnecessary antibiotics
2. Remove catheter if present
3. Treat only if symptomatic or high-risk

For diabetic patients: 3

1. Remove catheter if present
2. No treatment required if asymptomatic
3. If symptomatic, treat with fluconazole 200 mg daily for 14 days

For immunosuppressed patients: 4, 1

1. Assess for multi-site Candida colonization
2. Send blood cultures if colonized at ≥2 sites
3. Consider empiric antifungal therapy if septic or neutropenic