Bacteria can travel from one continent to another

These aerosols act like a "launch vehicle" for bacteria, and may pose risk of disease transmission across continents.

London: Some bacteria can travel from one continent to another ‘hidden’ in atmospheric dust, according to a new study which says these microbes may not only affect human and animal health, but also impact climate and ecosystems.

The research, published in the journal Atmospheric Research, deciphered the mystery of the transport of microorganisms across continents via ‘giant’ atmospheric particles called iberulites that could be inhaled by humans.

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These aerosols act like a “launch vehicle” for bacteria, and may pose risk of disease transmission across continents. In the current study, the researchers analysed atmospheric dust deposits in the city of Granada in Spain.

They found that the composition of these deposits was heterogeneous, comprising predominantly clay, quartz, and carbonate minerals and, iron oxides to a lesser extent.
In addition to these minerals, the scientists said bacteria, silicon-rich algae called diatoms, and other single-celled organisms made up the biological component.

Analysing the iberulites, the researchers found that they formed as a result of chemical and physical interactions between dust grains, the microorganisms from Saharan soils which initiate the aerosol formation, and water-vapour molecules from clouds.

“Bacteria can survive in iberulites because these provide a nutritious medium, a microhabitat rich in nutrients, and they protect the bacteria from ultraviolet radiation,” said Alberto Molinero Garcia, a co-author of the study from UGR.

According to the researchers, the iberulites aid microorganisms to travel great inter-continental distances on atmospheric currents such as the Saharan Air Layer (SAL).