Molecular-based Comparison of Bioaerosol Sampling Instruments

NOHHYEON KWAK, Mohammad Washeem, Yang Wang, Chang-Yu Wu, Jiayu Li, University of Miami

     Abstract Number: 149
     Working Group: Bioaerosols

Abstract
The composition of bioaerosol is a crucial parameter in the transmission of pathogenic diseases, and molecular-based analysis is a powerful tool for identifying the biological composition of aerosols. Another important tool in understanding transmission is the bioaerosol sampler, which plays a pivotal role in capturing airborne microorganisms as a function of size. However, selecting a proper bioaerosol sampler is hard since the size-dependent collection efficiency affects the bioaerosol characteristics and biological diversity varies with capturing size ranges. Indeed, previous studies showed different bioaerosol diversity among samplers operating on different principles.

This study aims to compare bioaerosol samplers through molecular-based analysis of the samples collected by these samplers. We evaluated three popular sampling instruments, i.e., a swirling aerosol collector (Biosampler®, SKC Inc.), a water condensation growth tube bioaerosol sampler (SPOT sampler, Handix Inc.), and a cascade impactor (Sioutas impactor, SKC Inc.). We compared their collection efficiency and microbial diversity using 16S rRNA gene amplicon sequencing.

The Biosampler was easy to deploy with rapid sampling but exhibited lower collection efficiency than the SPOT sampler (p > 0.05). The SPOT sampler demonstrated the best collection efficiency across size ranges among the three samplers but necessitated extended sampling durations to exceed the detection limit for molecular analysis due to its low flow rate (1.5 Lpm). For the filter-based sampler, the Sioutas impactor provided valuable size information but showed different microbial diversity due to different collection materials. Our analysis employed DNA sequencing to assess bacterial diversity, revealing distinct variations among samplers. Principal Component Analysis (PCA) and Beta diversity using the Bray-Curtis method highlighted distinctive microbial compositions associated with each sampler, emphasizing the importance of informed selection for accurate representation.

This comprehensive comparison will elucidate the strengths and limitations of commonly used bioaerosol samplers, guiding researchers in selecting appropriate tools for diverse sampling scenarios.