Nanoplastics could be interfering with antibiotics, making crucial drugs less effective and contributing to the rise of dangerous drug-resistant superbugs.
Using one of the most common antibiotics, called tetracycline, rresearchers in Sweden, Germany and Hungary created a computer model to see how the drug interacted with pieces of plastic that were less than one-thousandth the thickness of a credit card.
They then tested what they learned in the model on human cells grown in the lab. It turns out that antibiotics bind to the surface of tiny plastic molecules.
This can cause medications to hitchhike on pieces of plastic circulating in the bloodstream, being transported away from the infection they are intended to cure and into parts of the body they are not intended for, becoming less effective overall.
And because of the importance of microplastic pollution in the environment and in our bodies, found from the deepest sections of the ocean to Mount Everest, researchers are concerned that antibiotics used to treat life-threatening diseases will no longer are effective.
Lead author Lukas Kenner, professor at the Department of Molecular Biology at Umeå University, Sweden, said: “The results are alarming given how common nanoplastics are and because effective antibiotics for many can make the difference between life and death.”
Professor Kenner suggested that drugs that sequester plastic could make antibiotic-resistant superbugs more common.
An illustration of the bacteria Pseudomonas aeruginosa, a bacteria that can cause pneumonia, urinary tract infections, and wound infections. Studies show that some strains have evolved to become resistant to antibiotics, making Bacterium Pseudomonas one of the top six causes of death globally in 2019.
Because incorrect use of antibiotics can cause bacterial colonies to grow and mutate more quickly, these microplastics could make it easier for bacteria to become impervious to drugs designed to treat them.
And if bacteria or fungi become resistant to antibiotics, they can grow and spread uncontrollably, making usually treatable infections impossible to cure.
According to the Centers for Disease Control and PreventionAbout 2.8 million of these infections occur each year, killing about 35,000 Americans each year. The most common include Streptococcus pneumoniae, which causes pneumonia, Enterobacteriaceae, which causes food poisoning, and Staphylococcus aureus, which causes skin infections.
The CDC considers this trend, which continues to grow, an “urgent global threat.”
The new research linking plastics to this problem was published in the journal Scientific Reportsand focused on four different types of nanoplastics.
These are pieces of plastic that have broken down to a length of less than a thousandth of a millimeter, even smaller than microplastics, which measure five millimeters or less.
These come from polyethylene, polypropylene, polystyrene and nylon, which are found in plastic packaging, styrofoam and clothing with synthetic materials such as nylon.
Heating, tearing, or abrading any of these materials can cause small pieces of the product to break off, where they are propelled by air or water.
These are invisible to the naked eye and can be inhaled through small tracts in our lungs or swallowed.
From there, they reach humans when we breathe or drink water containing the particles.
They have become so common that researchers have found them in human blood, breast milk, and the brain. According to the researchers, these particles are approximately five times more abundant in indoor air than in outdoor air.
For their research, the team used a computer algorithm that was able to model how antibiotics dissolve and interact with plastic pieces and then predict how they are used in the body.
They used one of the most prescribed antibiotics, tetracycline, which treats everything from acne to pneumonia to tick-borne infections.
The researchers found that all four types of plastic were able to adsorb the antibiotic itself, carrying it through the bloodstream away from the infection they were designed to treat.
Nylon particles were the most absorbent, followed by polystyrene, polypropylene, and polyethylene.
The authors said nylon is one of the most common nanoplastics found in indoor air.
Nylon is a strong, elastic synthetic fiber commonly found in sports clothing, seat belts, and ropes.
Nanoplastics range in size from 1 to 1,000 nanometers, smaller than what is visible to the naked eye. These are even smaller than the microplastics, shown above, which measure five millimeters or less.
After using computer models, the researchers tested the scenario on human cells grown in a test tube.
They did this by adding samples of the nanoplastic to the test tube and then applying the antibiotic.
The results mirrored what was found in the computer modeling: they showed that the amount of antibiotic that ended up in the cells was altered when plastic was present, as the antibiotic molecules attached to the surface of the nanoplastics rather than being directed directly. to cells to attack an infection. .
Professor Kenner said: “Although more research is needed to shed light on the connections and possible measures, we can conclude from our results that nanoplastics are a health risk that should be taken more seriously.”
Antibiotics are a powerful class of drugs used to kill bacteria and fungi that make people sick, but pathogens are living organisms that can sometimes evolve and fight drugs designed to destroy them.
Not following proper instructions for taking an antibiotic, stopping it too soon, skipping doses, or mixing it with substances that weaken it can increase the chance of developing antibiotic resistance.
Tetracycline (pictured) is one of the most prescribed antibiotics. Similar medications include doxycycline, minocycline, and omadacycline.
For example, sometimes people stop taking antibiotics when they feel better, not when they finish their prescription.
Doing so can potentially leave behind a colony of bacteria, which can then multiply and mutate, transforming into a strain resistant to the drug.
The researchers suggested that nanoplastics could have a similar effect by making antibiotics less effective.
The new study comes as scientists warn that antibiotic resistance is increasing.
Recent investigations of the Global Burden of Disease Collaborators on Antimicrobial Resistance It suggested that if current trends persist, by 2050 there will be 39 million deaths each year attributed to antimicrobial resistance.
This means that diseases that are now easily treatable, such as urinary tract infections or food poisoning, could become deadly.
Therefore, the WHO calls antimicrobial resistance “one of the main global threats to public health and development.”
In addition to the products we use in our homes, other sources of nanoplastics include tires, cosmetics, and seed coatings.
Older studies have linked particles to a range of health problems, from developmental delay to colon cancer and mood, according to the Association of American Medical Colleges.
It’s difficult to avoid plastics in everyday life, but there are steps you can take, Dr. Sheela Sathyanarayana, a professor in the Department of Pediatrics at the University of Washington, told AAMC.
This includes using stainless steel water bottles instead of single-use plastics, avoiding reheating food in plastic containers, purchasing glass, wood or steel cookware, and removing your shoes when you get home to avoid leaving trails of dust. .