Liofilchem® Flucytosine AFY Antimicrobial Susceptibility Discs

Liofilchem® Flucytosine AFY Discs are high-precision antifungal susceptibility testing (AFST) discs designed for in vitro use with the Kirby-Bauer disk diffusion method, specifically for testing the susceptibility of yeasts such as Candida spp. and Cryptococcus neoformans. Each disc is impregnated with either 1 µg or 10 µg of Flucytosine (5-fluorocytosine), an antimetabolite antifungal agent that inhibits DNA and RNA synthesis. Manufactured under ISO 9001 and ISO 13485 standards, these discs are essential for evaluating antifungal activity, guiding therapy, and detecting resistance in clinical and research settings.

Key Features

• Two concentrations available: Choose from 1 µg or 10 µg discs depending on test objective and sensitivity requirements.
• Active against pathogenic yeasts: Especially effective against Candida albicans, Candida tropicalis, and Cryptococcus neoformans.
• CLSI and EUCAST compliant: Supports standardized antifungal disk diffusion testing protocols.
• Sterile and ready-to-use: Sealed packaging with desiccant ensures long-term stability and potency.
• Color-coded labeling: Allows quick identification of disc concentration and compound.

Applications and Use Cases

1. Clinical Mycology

Used in medical laboratories to:

• Assess antifungal susceptibility of:
  • Candida albicans, C. tropicalis, C. glabrata
  • Cryptococcus neoformans
• Support treatment of:
  • Cryptococcal meningitis (often in combination with Amphotericin B)
  • Systemic candidiasis and urinary candidiasis

2. Antifungal Resistance Surveillance

• Detect primary or acquired resistance to Flucytosine in Candida and Cryptococcus spp.
• Track resistance trends among immunocompromised patients (e.g., HIV/AIDS, transplant recipients).

3. Research and Development

• Evaluate antifungal synergy in combination with Amphotericin B or Azoles.
• Study mechanisms of resistance, including cytosine deaminase pathway mutations.
• Use in comparative antifungal efficacy and compound screening studies.

Use Instructions

1. Prepare Mueller-Hinton agar supplemented with 2% glucose and 0.5 µg/mL methylene blue (per CLSI M44 or EUCAST guidelines).
2. Standardize fungal inoculum to 0.5 McFarland using a turbidimeter or standard.
3. Inoculate the agar surface evenly with a sterile swab.
4. Apply a Flucytosine disc (1 µg or 10 µg) using sterile forceps or a disc dispenser.
5. Incubate at 35 ± 2 °C for 20–24 hours (extended incubation may be needed for Cryptococcus).
6. Measure the zone of inhibition in millimeters.
7. Interpret results using the latest CLSI M44-A or EUCAST breakpoint values.

Storage and Shelf Life

• Storage Conditions: 2–8 °C (refrigerated), stored in sealed packaging with desiccant.
• Shelf Life: 24–36 months from the date of manufacture under recommended conditions.

Liofilchem® Flucytosine AFY Discs (1 µg, 10 µg) provide a precise, standardized method for assessing susceptibility to a critical antifungal used in the treatment of life-threatening fungal infections. These discs are vital tools for diagnosing resistance, guiding therapy, and supporting antifungal stewardship in high-risk populations. Their accuracy, international compliance, and flexibility in dosing make them essential for both clinical mycology and antifungal research.