Seasonality in airborne bacterial, fungal, and (1→3)-β-D-glucan concentrations in two indoor laboratory animal rooms.

AIMS

The purpose of this study was to assess the temporal changes in the concentrations of bioaerosols in a laboratory mouse room (LMR) and laboratory rabbit room (LRR), and to determine environmental factors associated with the culturable bacteria, fungi and (1→3)-β-D-glucan concentrations.

METHOD

The concentrations of culturable airborne bacteria, fungi and (1→3)-β-D-glucan in the LMR and LRR were sampled once a month from March 2011 to February 2012. A single-stage viable cascade impactor was used to sample bacteria and fungi, while a two-stage cyclone bioaerosol sampler was used to collect airborne (1→3)-β-D-glucan.

RESULTS

The culturable bacterial concentrations in the LMR showed a gradual increase during the summer. The culturable fungal concentrations showed similar seasonal patterns of change in the LMR and LRR with a noticeable increase during the summer. The (1→3)-β-D-glucan concentrations were highest during the warmer spring and summer months. Relative humidity (RH) was the environmental factor most associated with the concentrations of culturable bacteria and fungi. The overall airborne microbe concentrations were significantly higher in the LRR than in the LMR.

CONCLUSIONS

Airborne microbe concentrations in the LMR and LRR varied greatly depending on season, and these changes were affected by environmental factors.