Diverse Communities of Bacteria Hitching on Airborne Dust can Affect Environment and Health, Scientists Puzzled

Scientists are perplexed by how bacteria carried by airborne dust can affect the environment's chemistry and both human and animal health.

Attached bacteria travel with dust when it is blown off the ground. Aerobiomes are made up of these airborne bacteria, which when the dust settles again, can change the chemistry of the environment and have an impact on both human and animal health, though scientists are unsure exactly how.

Diverse Communities of Bacteria on Airborne Dust

In a recent study, Daniella Gat and team members collected airborne dust in Rehovot, Israel, at various times. The bacterial community formation in the dust was determined by DNA sequencing, and its origins were discovered by trajectory modeling. The researchers discovered that diverse bacterial communities could be transported by dust from various regions, including Saudi Arabia, North Africa, and Syria, from hundreds, or even thousands of kilometers away.

The researchers compared Israel's aerobiomes to bacterial communities found on plant leaf surfaces, in Israeli soils, in seawater from the Red and Mediterranean Seas, and in dust collected in Saudi Arabia near the Red Sea to ascertain where the bacteria in Israel's aerobiomes originated. Aerobiomes obtained in Israel are also most similar to aerobiomes gathered in Saudi Arabia, demonstrating that a sizeable portion of the bacteria in Israeli air-roughly 33%-can originate from distant places, Cailisbbv reports.

In Israel, bacterial communities found on the ground exhibited less similarity to aerobiomes. However, the average number of bacteria in Israel's aerobiome came from Israeli soils, suggesting that soil and aerobiomes can exchange a sizable number of bacteria. Plant surfaces (11%) along with water from the Red and Mediterranean Seas (0.9%) contributed less aerobiome bacteria.

Genes in Aerobiomes

The researchers compared the bacterial genes hitching on airborne dust in Israel with that of the communities from the other investigated environments to better understand how aerobiomes may affect environments and health. They discovered that on average, compared to bacteria in seawater, plant surfaces, or soils, dust bacteria contained higher proportions of genes that biodegrade organic pollutants like benzoate and confer antibiotic resistance.

Higher proportions of these genes, in their opinion, point to widespread anthropogenic influences on the structure and operation of aerobiome communities.

According to the researchers, dust-driven displacement of antibiotic resistance genes could have an impact on human and livestock health; however, site-specific analyses are required to determine whether dust actually introduces new antibiotic resistance to a specific location. Furthermore, dust-borne bacteria that are resistant to antibiotics might not be alive. To verify this, the researchers propose to examine dust samples for bacterial RNA, which would represent living bacteria cells, Phys Org reports.

The study by Gat and his team members was recently published in the Journal of Geophysical Research: Biogeosciences. The group talked about the microbiome of atmospheric dust events and how, over the past ten years, there has been a growing amount of research that has characterized the various factors influencing the composition of the aerobiome, and the microbiome of the atmosphere.