AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Spatiotemporal Analysis of Microbial Diversity Patterns from the 454 Pyrosequencing of Bioaerosols Recovered from Flooded Commercial Office Environments
Kevin McCabe, Alina M. Handorean, Bharath Prithiviraj, Alison L. Ling, Keeley Hernandez, Norman R. Pace, MARK T. HERNANDEZ, University of Colorado at Boulder
Abstract Number: 468 Working Group: The Indoor Microbiome
Abstract Indoor microbiome studies seek to understand the ecological signatures of airborne microbial communities, and the associated potential to affect human and animal health. A recent study using high-throughput sequencing has determined that the diversity and composition of microbes within commercial office buildings qualify to be compared to complex ecosystems. Indoor bacterial diversity can be comprised of a multitudes of microbial taxa that may interact with each other, with humans and the indoor infrastructure (Green et al. 2012). Culture-independent methods, such as high-throughput molecular sequencing that leverages robust data analysis tools (e.g., QIIME & MGRAST) have transformed research on the human microbiome and the microbial ecology of aquatic and terrestrial ecosystems (Turnbaugh et al., 2007; Caporaso et al. 2010; Nemergut et al., 2011). Until recently, there have been few attempts to comprehensively survey the microbiome associated with the built environment (Rintala et al., 2008; Tringe et al., 2008; Amend et al., 2010). We present a study in which DNA-free liquid impingers collected composite air samples within flooded and non-flooded areas of the Engineering Center at the University of Colorado Boulder, which suffered extensive water damage following a catastrophic water pipe failure on its upper floors. Aerosol sampling was initiated within 48 hours of the breach, and continued for at least 60 days. 454 pyrosequencing of bacterial 16S rRNA genes was performed from DNA extracts of aerosol samples. Sequence data processing, based on custom barcode sequences, was performed using the QIIME pipeline at a 97% homology level using UCLUST. Sequence alignment using the PyNAST algorithm was performed, and taxa assignment at the Genus level followed using the RDP classifier retrained with the Green genes dataset.
Phylogenetic analyses of bioaerosols that were recovered from flooded indoor sites undergoing renovations, suggested an increased representation of Acinetobacter sp., Staphylococcus sp. and Streptococcus sp, over those aerosols recovered from proximal non-flooded areas, and the immediate outdoor environment (where these species were completely absent). These genera continue to be associated with respiratory diseases and nosocomial infections in many health care settings. Alpha diversity analysis revealed increased presence of these taxa in the days immediately following the flood, as well as several weeks (53 days) post-flooding. The results suggest that airborne microbial loads can be significantly influenced by water damage in both short- and long-time frames, regardless of conventional renovation activities to the indoor environment.