Although antibiotics can treat a variety of harmful bacterial infections, but the latest research shows that they may also help in some conditions, as a stimulus to bacteria. A study published in Nature Ecology & amp; Evolution showed that the mutations required for rapid drug resistance in Escherichia coli exposed to antibiotics increased the size of the population to three times.
Robert Beardmore of the University of Exeter in England is the author of this article. "We humans from a clinical point of view, antibiotics in a sense to prevent the growth of bacteria, but for bacteria, antibiotics may be something else in this study, it may be a stimulus." "
Beardmore's team exposed E. coli to eight rounds of doxycycline over a four-day period. During this time, they measured the rate of growth of the bacteria and repeated sequencing of the DNA samples in the culture to understand how the gene resistant to doxycycline was rapidly formed.
Consistent with the expectations, the researchers found that the antibiotic resistance increased after each treatment. However, it is surprising that the mutant E. coli proliferated faster than before, forming a group that was three times higher than before. When the researchers withdrew the drug, the evolutionary change did not disappear and the newly discovered ability remained.
Beardmore said: "It is often said that Darwinian evolution is slow, but when the bacteria hit antibiotics, the situation is not the case. Bacteria has a special ability to rearrange its DNA, which can prevent the drug work, sometimes only a few days While DNA rapid changes may be dangerous for human cells, there may be some benefits for E. coli.
Researchers have found some well-known changes, such as E. coli produced more antibiotic efflux pump, the antibiotics out of the body. In addition, they also found that dormant viral DNA, which is usually present in bacteria, is rapidly lost. Beardmore argues that the choice of viral DNA is to improve the metabolic efficiency of the antibiotic environment.
"Almost overnight, Escherichia coli reacts quickly to drugs in an irreversible way," says Beardmore. "Therefore, in the clinical environment, the early use of the right drugs is essential, because in the first few days you will find irreversible adaptability changes.