AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Genomic RNA as a Physical Tracer in Filovirus Aerosol Studies
TAMIKA KNIGHT, Michael Schuit, Shanna Ratnesar-Shumate, Paul Dabisch, NBACC
Abstract Number: 89 Working Group: Bioaerosols
Abstract Non-labile tracers are important in aerosol studies examining the persistence of microorganisms. The co-aerosolization of a tracer which can be quantitated in parallel with the biological activity of a microorganism allows for separation of physical losses from losses of biological activity, and calculation of a biological decay rate, which can be utilized to estimate the spread of disease and ultimately inform preparedness and response efforts. Substances commonly used as tracers in aerosol studies include fluorescent microspheres, soluble fluorescent salts, and, more recently, nucleic acids measured using quantitative PCR (q-PCR). Use of nucleic acids as a physical tracer is desirable as chemicals commonly added as tracers have occasionally been shown to be toxic to the microorganism or alter the aerodynamic properties of the aerosol. The objective of this study was to examine the use of filovirus genomic RNA quantitated with q-PCR as a physical tracer in aerosol studies. Filovirus suspensions containing a fluorescent microsphere were aerosolized into a small aerosol chamber and periodically sampled with both an Aerodynamic Particle Sizer (APS) and 25-mm gelatin filters. Gelatin filters were dissolved and utilized for both q-PCR and fluorescence measurements. The dissolved filter samples were diluted in Trizol LS and viral RNA for real-time reverse transcription-PCR (RT-PCR) amplification was extracted using a Direct-zol RNA MiniPrep kit. Primers for Ebola and Marburg were obtained from the US-DoD Critical Reagents Program. The physical decay rate of the aerosols generated within the chamber was estimated from APS particle counts, genomic equivalents as determined by q-PCR, and microsphere fluorescence. Results comparing the use of genomic RNA as physical tracer to results obtained using either the APS or a fluorescent microsphere to track physical losses will be presented. These data will be utilized to support future studies examining the biological decay rate of aerosolized filoviruses.