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Published on: March 7, 2016

Streptomycetes in house dust: associations with housing characteristics and endotoxin

E Johansson1, S Vesper, L Levin

  • 1Department of Environmental Health, University of Cincinnati, OH, USA.

Indoor Air
|January 6, 2011
PubMed

Insights

The presence of two or more dogs in a home significantly increases indoor streptomycetes and endotoxin levels, bacterial components linked to respiratory health issues. Other factors like season and outdoor mold influence streptomycetes but not endotoxin.

Area of Science:

  • Environmental microbiology
  • Indoor air quality
  • Human health impacts

Background:

  • Indoor bioaerosols include bacterial components like endotoxin (from Gram-negative bacteria) and Streptomyces (Gram-positive bacteria), both with potential respiratory health implications.
  • Endotoxin is known to cause respiratory issues, while some Streptomyces species can induce inflammatory responses.

Purpose of the Study:

  • To identify predictors of Streptomyces levels in house dust.
  • To compare the variability of Streptomyces levels with endotoxin levels in indoor environments.
  • To investigate the relationship between home characteristics and indoor bacterial contaminants.

Main Methods:

  • Dust samples were collected via floor vacuuming from 178 homes.
  • Streptomyces levels were quantified using quantitative PCR.
  • Endotoxin levels were measured using the Limulus amebocyte lysate assay.
  • Multiple regression analyses were performed to associate home characteristics with bacterial levels (concentration and load).

Main Results:

  • Having two or more dogs was a significant predictor for both Streptomyces and endotoxin levels.
  • Season of dust collection and outdoor mold levels predicted Streptomyces, but not endotoxin.
  • The number of inhabitants significantly predicted endotoxin load, but not Streptomyces.
  • Neither bacterial component was associated with indicators of moisture damage.

Conclusions:

  • Pet ownership, specifically multiple dogs, is a key factor influencing indoor Streptomyces and endotoxin.
  • Environmental factors like season and outdoor mold play a role in Streptomyces presence, independent of endotoxin.
  • Indoor bacterial bioaerosols are influenced by a complex interplay of factors, not solely by moisture issues.

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