Size-Resolved Community Structure of Bacteria and Fungi Transported by Dust in the Middle East

Abstract

The atmosphere plays an important role in transporting microorganisms on a global scale, yet the processes affecting the composition of the airborne microbiome, the aerobiome, are not fully outlined. Here we present the community compositions of bacteria and fungi obtained by DNA amplicon-sequencing of aerosol samples collected in a size-resolved manner during nine consecutive days in central Israel. The campaign captured dust events originating from the Sahara and the Arabian deserts, as well as days without dust (“clear days”). We found that the source of the aerosol was the main variable contributing to the composition of both fungal and bacterial communities. Significant differences were also observed between communities representing particles of different sizes. We show evidence for the significant transport of bacteria as cell-aggregates and/or via bacterial attachment to particles during dust events. Our findings further point to the mixing of local and transported bacterial communities, observed mostly in particles smaller than 0.6 μm in diameter, representing bacterial single cells. Fungal communities showed the highest dependence on the source of the aerosols, along with significant daily variability, and without significant mixing between sources, possibly due to their larger aerodynamic size and shorter atmospheric residence times. These results, obtained under highly varied atmospheric conditions, provide significant assurances to previously raised hypotheses and could set the course for future studies on aerobiome composition.

Functional Genes Profile of Atmospheric Dust in the East Mediterranean Suggests Widespread Anthropogenic Influence on Aerobiome Composition

“…Applying NMDS ordination on Bray-Curtis distances for the same data set produced similar results (Figure S2 in Supporting Information S1). These results are in agreement with Gat et al (2017Gat et al ( , 2021.…”

“…The soils selected for comparison in this study were desert crusts from the Israeli Negev desert ( Negev_soil ) and various soils from different sites in Israel ( IL_soils ). It was previously shown that during a dust event, the most significant change in community composition compared with nondusty conditions is observed in the coarse particulate fraction, that is, >3 μm, representing particles and bacterial aggregates (Gat et al., 2021). Thus, the increasing similarity between soils and dust events with increasing PM 10 concentrations is expected and further demonstrates the role of dust events in injecting soil microorganisms into the atmosphere, thereby affecting the aerobiome diversity and richness.…”

Infectious Diseases Associated with Desert Dust Outbreaks: A Systematic Review

“…All studies were published between 2004 and 2021 [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 ]. The affected regions that were studied were Asia (32/51, 62.7%), followed by Europe (9/51, 17.6%), America (6/51, 11.8%), Africa (4/51, 7.8%) and Australia (1/51, 2.0%).…”

“…and Coxiela burnetti , as well as Coccidioides spp. fungus and influenza A virus [ 10 , 16 , 22 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ]. The remaining studies reported opportunistic pathogens, mostly Bacillus spp., Aspergillus spp., etc.…”

Volatile sulfide compounds and oral microorganisms on the inner surface of masks in individuals with halitosis during COVID-19 pandemic

“…www.nature.com/scientificreports/ P. intermedia, E. corrodens, and L. casei, which had a significant positive correlation between bacteria collected saliva and those from mask samples, and that also demonstrated surface adhesion in previous studies [40][41][42] . For delivery and migration from the oral cavity to the inner surface of the mask through the saliva droplets, the size and surface characteristics of the bacteria should be considered 43 . Unfortunately, few studies have systematically compared the differences in size and/or surface adhesion of these bacteria.…”