Antibiotic resistance spreads in the air we breathe, warn scientists

T The thick fog along the San Francisco Golden Gate is synonymous with the Bay Area. But more than an emblem for the coastal city, fog can also represent a massive highway for genes that create dangerous and antibiotic-resistant "super-insects," warn scientists in a study published in Environmental Science and Technology . The appearance of super bacteria because of the overprescription and misuse of antibiotics is already quite difficult to control, but now, it looks like they can emerge from the air.

The alarming spread of super gonorrhea and Staphylococcus aureus infections shows how much the problem of antibiotic-resistant bacteria has become. In January, the World Health Organization found that 500,000 people in 22 countries had antibiotic-resistant infections that were almost impossible to treat. The reason these superbugs are so dangerous is that they carry certain antibiotic resistance genes (ARGs) that protect them from most drugs.

Usually, ARGs spread when a lucky superbug survives after a dosage of antibiotics kills most of its comrades, allowing this superbug to multiply, creating its own colony of servants who share his superior genetic material. But the team behind the new study found that in these ARGs can spread differently: They can become airborne traveling from bacteria to bacteria around the world – creating new forms of superbugs.

"ARGs could travel in the air to remote areas or other places where antibiotics are used less," author of the Maosheng Yao Ph.D. study from the College of Science and engineering of Peking University tells Inverse. "Common bacteria could become antibiotic-resistant when taking these ARGs."

Airborne ARGs make Yao and his team nervous because they represent the second method of gene accumulation bacteria, more difficult to manage. Unlike animals that have to wait until birth to transmit their genetic material to the next generation, bacteria can be injected one over the other with genetic material, including ARG. The effects are permanent because the genes are encoded in the DNA of the receptor bacteria.

This process, called Horizontal Transfer is what makes air resistance such a threat. The currents of air circulating in urban environments swirl millions of people every day, which greatly increases the possibility that a typical resistant bacterium encounters a resistant antibiotic.

Globetrotting ARGs

The observation discordant raised two questions for Yao. Which cities in the world are hot spots of ARG tourism, and how are they in the air in the first place?

To study this, the team sampled the level of bacteria in the air from 19 cities including San Francisco, Beijing, and Paris using a particularly ingenious method. They randomly selected cars from each city and took samples of particles that had accumulated inside the AC filters, which were found to accurately represent the particles in the outdoor pollutants. By scraping the filters themselves, the team had a lot of samples to track their ARGs.

Their screening revealed 30 different types of ARG that make bacteria resistant to seven types of antibiotics.

Beijing, China and Brisbane, Australia topped the list as the cities with the largest ARG diversity in the world. air, but the types of ARG in the air varied a lot from one city to the other. For example, Melbourne's air contained high levels of aerial genes that conferred resistance to drugs such as penicillin and low levels of genes conferring resistance to ciproflaxine, an antibiotic used to treat typhoid

. the highest concentrations of ARG in their air: San Francisco. Although the city has less air pollution than particle – dense cities like Beijing, Yao was surprised to discover that the Bay Area had more airborne ARGs than Paris, Beijing, and Beijing. Singapore. ARGs as the relatively small city of Bandung, Indonesia.

"For some cities with good air quality, we detected a greater abundance of ARG, including even ARGs tailored to withstand the most potent antibiotics". ] Where do they come from?

Yao suggests that these genes come from wastewater treatment plants, hospitals or animal feed operations. Wastewater, in particular, is often treated with antibiotics that, if they fail to kill all bacteria, could lead survivors to develop a multitude of resistance genes. Previous research has also shown that wastewater is likely to be aerosolized – which means that particles in the water can become airborne. Wastewater Treatment “/>

Regardless of the Spread of Antibiotic Resistance, It Is Time to Double the Antibiotic Resistance in a study mBio funded by industry on Tuesday. "Up to now, a lot of research efforts have been devoted to hospitals and the reduction of clinical prescriptions, but we now know that the environment plays a role in the evolution and the spread of antibiotic resistance, "said lead author William Gaze. , Ph.D. "We all need to think more holistically about environmental waste management, including how we treat our wastewater."