10th International Aerosol Conference
September 2 - September 7, 2018
America's Center Convention Complex
St. Louis, Missouri, USA

Abstract View


Exploring the Fundamentals of Biological Decay and Survival in Aerosol Droplets with a New In Vitro Technology

MARA OTERO-FERNANDEZ, Allen E. Haddrell, Jonathan P. Reid, Richard Thomas, University of Bristol

     Abstract Number: 364
     Working Group: Infectious Bioaerosol

Abstract
Understanding the parameters that determine the longevity of microorganisms during atmospheric transport is critical for public health and biodefense applications, ranging from outbreak control to risk analysis modelling. The study of bioaerosols in a laboratory environment is challenging and requires careful consideration of each experimental phase:

(1) Quantifying the complete droplet composition, from the individual to the population level, while minimizing microbial damage during the aerosolization process (Zhen et al. 2014).
(2) Complete control over the atmosphere (e.g. temperature, relative humidity) where the droplets are suspended whilst avoiding physical loss of the particles.
(3) Minimizing stresses that occur during aerosol sampling.

Conventional techniques for investigating the survival of bioaerosols in vitro have some limitations that can impact the accurate representation of conditions that these particles would experience in the environment. Therefore, some basic questions about the fundamentals of airborne disease dynamics remain unknown.

In this study, a recently developed technology that utilizes a droplet-on-demand aerosol generator to produce a tailorable number of bioaerosol droplets with designed composition, without compromising the microorganisms’ viability, will be demonstrated. These droplets are suspended in an electrodynamic trap where the internal atmosphere is highly-controlled regarding atmospheric parameters and chemical composition. After the desired suspension period and throughout manipulation of the electric field, the droplets are deposited onto a subtract with a high efficiency and time-resolution. By manipulating the substrate, the dissociation between viability and infectivity of the airborne pathogens contained within the droplets can be studied.

The findings to be presented will demonstrate some of the unique characteristics of this technique including:

a) The characterization of the first phase of cell death, achievable due to the high time-sampling resolution (under 10 seconds).
b) Longevity measurements of populations of droplets (whose absolute number can be readily counted) with accurate microbial and chemical composition. Correlations between the complete aerosol composition/concentration and longevity (with no physical loss component) will be explored.

Zhen, H. J. et al, G. J Aerosol Sci. 2014;70,67-79.