Microbial contents of vacuum cleaner bag dust and emitted bioaerosols and their implications for human exposure indoors

Authors: Veillette, Marc; Knibbs, Luke D.; Pelletier, ArianeCharlebois, RémiBlais Lecours, Pascale; He, Congrong; Morawska, Lidia; Duchaine, Caroline
Abstract: Vacuum cleaners can release large concentrations of particles, both in their exhaust air and from resuspension of settled dust. However, the size, variability, and microbial diversity of these emissions are unknown, despite evidence to suggest they may contribute to allergic responses and infection transmission indoors. This study aimed to evaluate bioaerosol emission from various vacuum cleaners. We sampled the air in an experimental flow tunnel where vacuum cleaners were run, and their airborne emissions were sampled with closed-face cassettes. Dust samples were also collected from the dust bag. Total bacteria, total archaea, Penicillium/Aspergillus, and total Clostridium cluster 1 were quantified with specific quantitative PCR protocols, and emission rates were calculated. Clostridium botulinum and antibiotic resistance genes were detected in each sample using endpoint PCR. Bacterial diversity was also analyzed using denaturing gradient gel electrophoresis (DGGE), image analysis, and band sequencing. We demonstrated that emission of bacteria and molds (Penicillium/Aspergillus) can reach values as high as 1E5 cell equivalents/min and that those emissions are not related to each other. The bag dust bacterial and mold content was also consistent across the vacuums we assessed, reaching up to 1E7 bacterial or mold cell equivalents/g. Antibiotic resistance genes were detected in several samples. No archaea or C. botulinum was detected in any air samples. Diversity analyses showed that most bacteria are from human sources, in keeping with other recent results. These results highlight the potential capability of vacuum cleaners to disseminate appreciable quantities of molds and human-associated bacteria indoors and their role as a source of exposure to bioaerosols.
Document Type: Article de recherche
Issue Date: 9 August 2013
Open Access Date: 19 December 2016
Document version: VoR
Permalink: http://hdl.handle.net/20.500.11794/12880
This document was published in: Applied and environmental microbiology, Vol. 79 (20), 6331-6336 (2013)
American Society for Microbiology
Alternative version: 10.1128/AEM.01583-13
Collection:Articles publiés dans des revues avec comité de lecture

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