Introduction

Sterility testing in a GMP-compliant mycology laboratory is a critical quality assurance process used to confirm that pharmaceutical products, culture media, reagents, water systems, and laboratory environments are free from viable microorganisms, including fungi and yeasts.
It follows regulatory guidelines defined by WHO, EU-GMP, USP <71>, EP 2.6.1, and ISO standards, ensuring that materials used in fungal diagnostics or research meet the highest safety and contamination-control requirements.

In mycology labs—where fungal spores are abundant—rigorous sterility testing safeguards aseptic processing, prevents cross-contamination, and ensures reliable diagnostic results.

Applications

1. Sterility Testing of Culture Media and Reagents

Ensures that SDA, PDA, broth media, LPDA, Calcofluor stains, KOH, and molecular reagents are free of contaminating fungi or bacteria before diagnostic use.

2. Sterility of Pharmaceutical and Clinical Products

Used for:

• Antifungal formulations
• Injectables
• Eye drops
• Parenteral solutions
• Medical devices and consumables

To ensure they meet GMP sterility requirements.

3. Environmental Monitoring in Mycology Labs

Detects fungal contamination in:

• Air
• Surfaces
• Biosafety cabinets
• Incubators
• Cleanrooms and aseptic zones

Using settle plates, active air sampling, and contact plates.

4. Water System Sterility (Purified Water/WFI)

Tests for fungal and bacterial contamination in:

• Water-for-Injection (WFI)
• Purified water systems
• RO/DI systems
• Laboratory sterilizers and autoclave water

5. Sterility Testing During Media Preparation

Validates aseptic preparation of media, agar plates, PCR reagents, and fungal transport media.

6. Sterility Assurance in Aseptic Procedures

Used during:

• Sample handling
• Inoculation
• Molecular assays
• Antifungal susceptibility testing
• Culture transfers

To ensure sterile technique and contamination-free workflows.

7. Validation of Cleaning and Disinfection Programs

Confirms that disinfectants, fumigation systems, and SOPs are effective against laboratory fungi.

Keynotes

• Sterility testing must follow USP <71>, EP 2.6.1, JP, and GMP Annex 1 guidelines.
• Mycology labs require enhanced fungal contamination control due to circulating spores.
• Two main methods are used: Direct Inoculation and Membrane Filtration.
• All testing must be performed in a Grade A/B environment using aseptic technique.
• Positive and negative controls are mandatory to validate sterility tests.
• Monitoring includes environmental surveillance, media sterility, and equipment validation.
• Autoclaves, BSCs, incubators, and cleanrooms must undergo regular qualification (IQ/OQ/PQ).
• Sterility testing results must be documented, traceable, and audit-ready as per GMP compliance.
• Fungal isolates found during sterility failures must be identified, and root-cause investigations performed.
• Prevents cross-contamination, ensures reliable fungal diagnosis, and maintains patient and product safety.

Further Readings

1. https://www.rocker.com.tw/en/application/sterility-testing/
2. https://www.who.int/teams/health-product-policy-and-standards/standards-and-specifications/norms-and-standards/sterility-testing
3. https://journals.asm.org/doi/10.1128/jcm.01357-21
4. https://www.merckmillipore.com/NG/en/applications/microbiological-testing/sterility-testing
5. https://www.npra.gov.my/images/Announcement/Archives/Slides-amv/AMV%20-%20STERILITY%20TEST.pdf
6. https://maze.conductscience.com/methods-of-cleaning-and-sterilization-in-the-laboratory/
7. https://microbe-investigations.com/usp-71-sterility-testing/
8. https://www.jove.com/science-education/v/19597/key-techniques-in-microbiology
9. https://academicjournals.org/journal/AJPP/article-full-text/9B1DBC756566