Until now scientists thought that if you were to remove antibiotics from the environment, antibiotic-resistant superbugs would not be able to compete with regular bacteria:
That’s because maintaining a chunk of DNA from another organism – or coping with a new antibiotic resistance mutation – uses up a cell’s resources and leaves it less competitive once the antibiotic has been removed…
New Scientist reports that studies have shown that a third of superbugs remained more competitive in the absence of antibiotics. The process is known as positive epistasis, but researchers have not yet figured out why it would happen.