Identifying bioaerosol diversity in theatmosphere of Vilnius, Lithuania, by molecular methods:Hints to clarify human bio-exposome.

Abstract

Background: Monitoring biological air particles is fundamental to prevent the spread of airborne allergic and infectious diseases. Traditional aerobiological identifications to track some bioaerosols, such as fungi, bacteria and viruses, poses significant challenges as accurate identification can be exceedingly difficult. Molecular methods can be useful to identify the biodiversity of the human exposome. The aim of this work was to compare de efficacy of different sample collectors for monitoring bioaerosols by molecular methods.

Method: The work was performed within the framework of the COST-ADOPT program. Sampling was performed using 4 different volumetric air samplers (VAS), each adjusted to 2 m3: a) 7-day multi-vial cyclone (Burkard); b) Coriolis μ (Bertin); c) Personal Volumetric Air Sampler (PVAS); d) microbiological air sampler (SAS). Collection surfaces on PVAS (c) consisted of filter paper or glass slide, while SAS (d) consisted of polypropylene surface dry or Vaseline coated. The two cyclones, Burkard (a) and Coriolis μ (b) used dry sampling. Sampling was done in June 2023 at 4 locations at Vilnius (Lithuania) vicinity: airfield (A); chicken farm (CF); dump site (D); university campus (UC). Total DNA was obtained using the NZY mag viral RNA/DNA isolation kit. DNA yield ([DNA]) was measured using a NanoDrop One.

Results: Significant differences were observed in the total [DNA] between different volumetric equipment (p = 0.009). The highest [DNA], 7.13 ± 3.07 ng/m3, was obtained with the Coriolis μ (b), compared to 4.02± 2.99, 3.85 ± 2.32 PVAS (c) and for the cyclone-B (a), respectively, and 2.02 ± 1.10 ng/m3 for SAS (d). We found no difference in [DNA] when changing sampling media on either the SAS (d) or the PVAS (c) sampler. Considering the different locations, high variability was observed with the Chicken Farm exhibiting the lowest [DNA].

Conclusion: These results indicate that the choice of sampling methodology significantly impacts the total amount of DNA collected, limiting the molecular sequencing opportunities and biodiversity analysis. This work contributes to a better understanding of the efficiency of different sampling methodologies, providing valuable insights on airborne biodiversity and human bioaerosol exposure.