Molecular Source Tracking of Bioaerosols in the Quarantined Katrina Flood Zone

Abstract

The emergency response following hurricanes Katrina and Rita included massive pumping and aeration operations to reduce biochemical oxygen demand (BOD) of floodwaters trapped within the city of New Orleans. Such engineering operations aerosolized tremendous quantities of water as microdroplets, which in turn increased the potential for waterborne microorganisms to partition into the atmosphere. To determine if remediation efforts significantly impacted local airborne microbe populations, or resulted in aerosolization of potentially pathogenic microorganisms, we performed direct microscopy, broad spectrum PCR, and DNA sequencing analysis on paired air and water samples collected in the immediate vicinity of turbulent pumping and aeration operations throughout flooded New Orleans. We report here that remediation activities following Hurricanes Katrina and Rita did not significantly impact bioaerosol ecology proximal to large engineering works, which promoted floodwater aerosolization. With exception to the minor representation of species associated with common skin infections, no pathogenic species were detected in this atmospheric sampling campaign. When compared to the growing genetic catalogues of atmospheric molecular ecology surveys, results from this sampling campaign were consistent with, but limited to, phylum level taxonomic patterns emerging from observations of outdoor bioaerosol communities.