French study says : Antibiotic-resistant bacteria can spread by clouds

Antibiotic-resistant bacteria are becoming more common and are a serious threat to public health and food safety. This is partly due to the widespread use of antibiotics. In addition, researchers from Quebec and France have suggested that bacteria with antibiotic-resistant genes may be able to spread through the air, even through clouds. This is a concerning possibility that we need to take seriously.

In a study recently published in the journal Science of The Total Environment, researchers examined samples obtained from clouds at the summit of Puy de Dôme, a dormant volcano located in central France that stands at an altitude of 1,465 meters above sea level.

The study's analysis of the cloud water samples revealed a significant variation in bacterial density, with concentrations ranging from 330 to over 30,000 bacteria per milliliter. On average, the concentration was found to be approximately 8,000 bacteria per milliliter.

According to the lead author of the study, Florent Rossi from Université Laval, this is the first research to demonstrate that clouds contain antibiotic resistance genes from bacteria, which are present in levels that are similar to those found in other natural environments. In a news release, Rossi explained that these bacteria normally reside on the surface of soil or vegetation and can be aerosolized by wind or human activities. Some of these bacteria can then ascend to the atmosphere and become part of cloud formation.

The scientists conducting the study measured the concentration of 29 different types of antibiotic-resistant genes and discovered that clouds had an average of 20,800 copies of these genes per milliliter of cloud water.

Rossi also noted that oceanic clouds and continental clouds exhibit unique signatures of antibiotic resistance genes. For instance, continental clouds were found to contain more antibiotic resistance genes that are commonly used in animal production.

Antibiotic resistance occurs when bacteria are exposed to antibiotics and develop the ability to resist these drugs. This phenomenon is becoming more common due to the increasing use of antibiotics in both healthcare and agriculture.

The World Health Organization has warned that the proliferation of antibiotic-resistant bacteria has made it increasingly challenging to treat a growing number of bacterial infections, including pneumonia, tuberculosis, and foodborne illnesses. As a result, patients are experiencing longer hospital stays, higher medical expenses, and an elevated risk of mortality.

Rossi emphasized that the study demonstrates the significance of clouds as a pathway for the spread of antibiotic-resistant genes over both short and long distances. He added that it would be desirable to identify the sources of these genes resulting from human activities to control their dispersal.