Recurrent Aspergillus contamination in a biomedical research facility: a case study.

Area of Science:

• Microbiology
• Biotechnology
• Forensic Science

Background:

• Fungal contamination poses significant risks to biomedical research facilities, causing financial losses and project delays.
• A specific biomedical research facility experienced persistent fungal contamination in clean room incubators over three years.

Purpose of the Study:

• To identify the source and persistence of fungal contamination in clean room incubators.
• To investigate the genotypic relationship of fungal isolates and their biofilm-forming capabilities.
• To evaluate the effectiveness of disinfection protocols against identified fungal contaminants.

Main Methods:

• Isolation and identification of fungal specimens using 18S rRNA gene sequencing.
• Genotyping of fungal strains via random amplified polymorphic DNA (RAPD) PCR.
• Biofilm formation assessment using confocal microscopy and visual inspection of incubator components.
• Disinfectant efficacy testing on fungal spore germination.

Main Results:

• Aspergillus niger and Aspergillus fumigatus were identified as the primary contaminants within incubators.
• RAPD analysis confirmed the continuous presence of the same Aspergillus fumigatus strain since 2007.
• Fungal biofilms were observed within incubator plugs, with isolated strains exhibiting robust biofilm formation.
• Standard disinfectants were ineffective against spores within these microenvironments.

Conclusions:

• Incubator rubber plugs created protected microenvironments allowing Aspergillus fumigatus survival and biofilm formation.
• Persistent contamination can occur when microenvironments harboring contaminants are not addressed in decontamination strategies.
• This case study underscores the importance of identifying and eliminating hidden contamination niches in biomedical facilities.