New research sheds light on key steps in the process of converting antibiotics into food by bacteria. The findings could lead to new ways to eliminate antibiotics from land and water, the researchers say.
"It's just carbon, and where carbon is, someone will figure out how to eat it."
"Ten years ago stumbled upon the fact that bacteria can eat antibiotics and everyone was shocked," says senior author Gautam Dantas, Associate Professor of Pathology and Immunology, Molecular Microbiology and Biomedical Engineering at Washington University in St. Louis School of Medicine.
"But now it starts to make sense, it's just carbon, and where carbon is, somebody will figure out how to eat it. Now that we understand how these bacteria do it, we can think about how we can use this ability to get rid of antibiotics where they cause harm. "
Drug resistance is a serious and aggravating problem that threatens medical care. At a time when scientists were still discovering antibiotics and infectious diseases, was the world's Cause No. 1
Modern industrial and agricultural practices are accelerating the increase in antimicrobial resistance by saturating the environment with active drugs. In India and China, which together produce most of the world's antibiotics, pharmaceutical factories sometimes throw waste laden with antibiotics into local waterways. In the United States, some farmers add antibiotics to their pet food to breed their livestock, producing waste loaded with the drugs.
Bacteria easily divide genetic material. Thus, when antibiotics infiltrate water and soil, resident bacteria respond by spreading antibiotic resistance genes throughout the community.
Researchers wanted to understand how some environmental bacteria not only withstand antibiotics, but also feed on them. They studied four distantly related types of soil bacteria, all thriving on a diet with penicillin alone.
Penicillin was the first antibiotic that scientists discovered, but it has fallen out of favor because of its resistance. Other members of the penicillin family, such as amoxycillin and ampicillin, are still effective and prescribed for the treatment of bacterial infections.
They found three different sets of genes that became active while the bacteria ate penicillin but were inactive while the bacteria were eating sugar. The three sets of genes are three steps taken by bacteria to turn a deadly compound into a meal.
All bacteria start neutralizing the dangerous part of the antibiotic. Once the toxin is disarmed, cut off a tasty serving and eat it.
Treating Dung Does Not Remove All Antibiotics
Understanding the steps involved in converting an antibiotic into food can help Bioengineer bacteria cleanse the soil Waterways that are contaminated with drugs slow down their spread of drug resistance.
The soil bacteria that naturally consume antibiotics are tricky and difficult to handle. But a more manageable species such as E. coli could possibly be developed to feed on antibiotics in polluted land or water.
Researchers showed that they have E. coli the ability to survive on penicillin and to thrive. The bacterium usually needs sugar, but with some genetic modification and the addition of a key protein, it flourished on a sugar-free diet of penicillin.
"With some intelligent technology, we may be able to modify bacteria to break down antibiotics in the environment," says Crofts.
Any such bioengineering project should have a plan to accelerate the process of antibiotic consumption. The way soil bacteria naturally remove antibiotics from the environment is effective but slow. They could not possibly handle the quantities of antibiotics near pharmaceutical factories and sewage treatment plants.
"You could not just sprinkle a field with these soil bacteria today and expect them to clean up everything," says Dantas. "But now we know how to do it, it's much easier to improve something you already have than to construct a system from scratch."
Ditching causes new types of antibiotics  The National Institutes of Health; the National Institute for Diabetes and Digestive and Kidney Diseases; the National Institute of General Medical Sciences; the National Institute of Allergy and Infectious Diseases; the National Institute for Child Health and Development; the National Human Genome Research Institute; the Edward Mallinckrodt, Jr. Foundation; the National Science Foundation; and the Mr. and Mrs. Spencer T. Olin Fellowship funded the work.
Source: Washington University, St. Louis