Antibiotic-resistant bacteria are on the rise. These are found in places where humans and animals congregate – as is the case on the Earth’s surface. But a group of researchers found them in an extraordinary place.
Antibiotic-resistant bacteria and fungi are responsible for death of at least 1.27 million people per year around the world, according to the Centers for Disease Control and Prevention, reported the New Atlas.
The fight against these superbugs is becoming increasingly difficult, although researchers are working on some innovative methods, including the use of gold and shape-shifting antibiotics.
Because of the significant public health threat posed by antibiotic-resistant microbes, it is critical to learn as much as possible about them and how they move around our planet.
That’s what researchers from Université Laval, in Canada, and Université Clermont Auvergne, in France, set out to do when they investigated the clouds that float around a dormant volcano in the Massif Central region, in French territory. The results were recently released at Science of The Total Environment.
Working from a meteorological station located at 1,465 meters above sea level, at the top of the Puy de Dôme, they carried out 12 cloud sampling sessions over two years.
Not only did they find that the clouds contained about 8000 bacteria per milliliter of water, but that there were, on average, 20 800 copies of antibiotic resistance genes in the same volume.
They also observed that clouds that had traveled paths that took them to the ocean had different types of bacteria resistant to antibiotics than those that passed exclusively over land – the latter had higher rates of bacteria resistant to antibiotics used in livestock.
Although the atmosphere has long been understood as a transit point for bacteria, researchers were surprised to find the same levels of genes in the clouds as they would find on the surface of the planet.
“This is the first study to show that clouds harbor antibiotic-resistant genes of bacterial origin in concentrations comparable to those in other natural environments”said Florent Rossi of Université Laval, the first author of the study.
“These bacteria normally live on the surface of vegetation or soil. They are aerosolized by wind or human activities, and some of them rise into the atmosphere and participate in cloud formation,” he added.
According to the authors of the study, the high concentration of antibiotic-resistant genes in the clouds is probably caused by the use of these drugs in animal husbandry.
“Our study shows that clouds are an important pathway for the dissemination of antibiotic-resistant genes in the short and long term,” said Rossi. “Ideally, we would like to locate emission sources resulting from human activities to limit the spread of these genes”he concluded.
ZAP // 
