Analysis of air samples taken at an altitude of three,000 meters over Japan has revealed a concentration of viable bacteria and fungi transported greater than 2,000 kilometers by air masses in regions wealthy in fertilizers and pesticides. There is a big selection. The research, published in , reveals a brand new way during which human, animal and plant pathogens can travel across distant geographic areas. The research is led by the Barcelona Institute for Global Health (ISGlobal), a middle supported by the “la Caixa” Foundation in collaboration with the Daniel Bravo Andrew Private Foundation (FPDBA).
Pathogens may be airborne, but little is thought concerning the diversity of microbes that may survive at high altitudes, where conditions are harsh. “We know that above a certain point in the troposphere (called the planetary boundary layer), some material can be transported long distances because the air in that region is isolated from the surface and there is less friction. But We didn't suspect that viable microorganisms might be there,” says Xavier Rudo, researcher at ICREA at ISGlobal.
“Our study is unique in that we conducted 10 tropospheric flights to examine microbial diversity at high altitudes, whereas most studies have been conducted only a few meters above the ground or ocean,” he adds.
Airborne microbes over Japan.
Using a Cessna aircraft, Rudo and a world team of colleagues conducted ten aerial surveys over Japan between 1,000 and three,000 meters altitude, starting at Chufu Airport near Tokyo. All the flights were planned to follow air currents from mainland Asia, often called tropospheric bridges, that connect the air to distant regions of the world. In this case, air that rises over mainland China after which descends on Tokyo as a result of winter weather conditions. Samples were also collected on the bottom at Chofu for comparison. A complete of twenty-two aerosol filter samples collected during two periods (February and April 2014) were analyzed for his or her chemical and biological composition.
DNA sequencing allowed the research team to discover greater than 266 fungal and 305 bacterial genera related to aerosols, a few of that are potentially pathogenic to humans, other animals or plants. For example, bacterial species corresponding to those identified, in addition to fungal species of genera corresponding to and, are able to causing disease in susceptible and immunocompromised individuals.
By culturing some samples, the researchers showed that airborne bacteria remained viable, and a few were proof against commonly used antibiotics. “Surprisingly, the isolated strain was resistant to multiple drugs, including carbapenems, glycopeptides, ciprofloxacin, and trimethoprim-sulfamethoxazole. Our results suggest that antimicrobial resistance can spread over long distances through this previously unrecognized pathway.” of study.
A journey of 1000's of kilometers
The association of those aerosols with certain elements corresponding to zinc sulfate and potassium, that are commonly utilized in fertilizers and pesticides, indicates an agricultural origin, corresponding to highly cultivated lands in northeastern China. .
Finally, in the course of the sampling days, the flight and ground samples were very similar when it comes to microbial diversity, which may very well be explained by air descent from high altitudes to the bottom. Particle transport models, created by Roger Kirkwell – currently a researcher on the Universitat Politècnica de Catalunya — BarcelonaTech (UPC) – showed the possible transport of those particles from northeast China and the landing of tropospheric air masses in Japan. Both have been confirmed for
“Our findings reveal a rich and unprecedented diversity of microbes that are dispersed by air currents thousands of kilometers away from their sources through strong wind tunnels that form high in the troposphere,” says Rudo. “They represent a paradigm shift in our understanding of how human health can be affected by pathogens that thrive in the environment, particularly in the air.”
Although this study doesn't prove a link between the presence of known human pathogens in aerosols and health effects, it emphasizes the necessity to further explore the long-range spread of varied microbial pathogens.