Aerometric study of viable fungus spores in an animal care facility

Area of Science:

• Environmental microbiology
• Laboratory animal science
• Occupational health

Background:

• Airborne fungi pose potential health risks (allergic/invasive disease) to lab animals and personnel.
• Understanding indoor fungal spore sources is crucial for risk assessment.

Purpose of the Study:

• To assess airborne fungal exposure risks in laboratory environments.
• To identify primary sources of indoor fungal spores.

Main Methods:

• Air sampling for viable fungal particles using malt extract agar and Sabouraud dextrose agar.
• Identification and quantification of recovered fungal taxa.
• Analysis of potential spore sources, including bedding and outdoor air.

Main Results:

• Overall viable fungal counts were generally low, despite sporadic high levels.
• Malt extract agar yielded significantly higher fungal recoveries than Sabouraud dextrose agar.
• Penicillium species were the most frequent and abundant fungi recovered.
• Laboratory bedding material identified as the principal source of airborne spores.
• Cleaning activities temporarily increased spore levels.
• Outdoor airborne fungi contributed minimally to the indoor air spora.
• Aspergillus fumigatus and dermatophytes were rarely or not detected.

Conclusions:

• Laboratory airborne fungal exposure, primarily from Penicillium species originating from bedding, presents a manageable risk.
• Standard cleaning protocols may temporarily increase airborne spore concentrations.
• Further investigation into bedding material treatments could reduce exposure risks.