Dust from the Arabian Peninsula blew over the eastern edge of the Mediterranean on September 29, 2011, potentially bringing bacteria along for the ride. Credit: Jeff Schmaltz, NASA GSFC, MODIS Rapid Response Team
When the winds blow the dust off the ground, the attached bacteria go along for the ride. These airborne bacteria make up aerobiomes, which, when dust settles back down, can change the chemistry of the environment and affect human and animal health, although scientists don’t know exactly how.
In a new study published in Journal of Geophysical Research: Biogeoscience, Daniella Gat and colleagues collected airborne dust at different times in Rehovot, Israel. The researchers used DNA sequencing to identify the composition of the bacterial community in the dust, while trajectory modeling revealed the origin of the dust. The researchers found that dust from different places, including North Africa, Saudi Arabia and Syria, can bring different bacterial communities from hundreds to thousands of kilometers away.
To determine where the bacteria in Israel’s aerobiomes come from, the researchers compared the aerobiomes with bacterial communities on plant leaf surfaces, in soil in Israel, in seawater from the Mediterranean and the Red Sea, and in dust sampled in Saudi Arabia near coast of the Red Sea. The aerobiomes collected in Israel were more similar to the aerobiomes collected in Saudi Arabia, indicating that a significant amount of the bacteria—roughly 33%—in Israeli air may come from distant locations.
Soil bacterial communities were less similar to aerobiomes in Israel. However, 34% of Israel’s aerobiome bacteria, on average, likely came from Israeli soils, indicating that the soil can exchange a significant number of bacteria with the aerobiome. Fewer aerobic bacteria were contributed from plant surfaces (11%) and water from the Mediterranean and Red Sea (0.9%).
Understanding how aerobiomes can affect environments and health requires scientists to know what genes they carry, so the researchers compared the bacterial genes observed in air dust in Israel with those of communities from other environments examined. They found that, on average, dust bacteria contain larger proportions of genes that biodegrade organic pollutants such as benzoate and confer antibiotic resistance compared to bacteria in seawater, plant surfaces or soils.
According to the researchers, higher proportions of these genes suggest widespread anthropogenic fingerprints on the composition and function of the aerobiome community.
The spread of dust-driven antibiotic resistance genes could affect human and livestock health, the researchers say, but site-specific analyzes are needed to test whether dust brings new antibiotic resistance to a particular location. In addition, antibiotic-resistant bacteria in the powder may not be viable. To test this, the researchers plan to look for bacterial RNA in the dust samples, which would indicate living bacterial cells.
More information:
Daniella Gat et al, Functional Gene Profiling of Atmospheric Dust in the Eastern Mediterranean Suggests Widespread Anthropogenic Influence on Aerobiome Composition, Journal of Geophysical Research: Biogeosciences (2022). DOI: 10.1029/2022JG007022
Provided by the American Geophysical Union
This story is reprinted courtesy of Eos, hosted by the American Geophysical Union. Read the original story here.
citation: Bacteria can travel thousands of kilometers in airborne dust (2022, November 22) retrieved on November 22, 2022 from https://phys.org/news/2022-11-bacteria-thousands-kilometers-airborne.html
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