Antibiotic-loving bacteria don't just resist drugs, they get a kick out of them
By www.sci-news.com
A team of scientists at the University of Exeter, UK, exposed Escherichia coli (E. coli) bacteria to eight rounds of antibiotic treatment over four days and found the bacteria had increased antibiotic resistance with each treatment.
This had been expected, but the authors were surprised to find mutated E. coli reproduced faster than before encountering the drugs and formed populations that were three times larger because of the mutations.
This was only seen in bacteria exposed to antibiotics — and when the team took the drug away, the evolutionary changes were not undone and the new-found abilities remained.
“Our research suggests there could be added benefits for E.coli bacteria when they evolve resistance to clinical levels of antibiotics,” said University of Exeter Professor Robert Beardmore, lead author on the study.
“It’s often said that Darwinian evolution is slow, but nothing could be further from the truth, particularly when bacteria are exposed to antibiotics.”
“Bacteria have a remarkable ability to rearrange their DNA and this can stop drugs working, sometimes in a matter of days. While rapid DNA change can be dangerous to a human cell, to a bacterium like E. coli it can have multiple benefits, provided they hit on the right changes.”
Prof. Beardmore and co-authors tested the effects of the antibiotic doxycycline on E. coli as part of a study of DNA changes brought about by antibiotics.
The bacteria that subsequently evolved was safely frozen at minus 80 degrees Celsius and the scientists used genetic sequencing to find out which DNA changes were responsible for its unusual evolution.
Some changes are well known and have been seen in clinical patients, like E. coli producing more antibiotic pumps that bacteria exploit to push antibiotics out of the cell. Another change saw the loss of DNA that is known to describe a dormant virus.
“Our best guess is that losing viral DNA stops the E.coli destroying itself, so we see more bacterial cells growing once the increase in pump DNA allows them to resist the antibiotic in the first place,” said study first author Dr. Carlos Reding-Roman.
“This creates an evolutionary force for change on two regions of the E. coli genome.”
“Normally, self-destruction can help bacteria colonize surfaces through the production of biofilms. You see biofilms in a dirty sink when you look down the plughole. But our study used liquid conditions, a bit like the bloodstream, so the E. coli could give up on its biofilm lifestyle in favor of increasing cell production.”
“It is said by some that drug resistance evolution doesn’t take place at high dosages but our paper shows that it can and that bacteria can change in ways that would not be beneficial for the treatment of certain types of infection. This shows it’s important to use the right antibiotic on patients as soon as possible so we don’t see adaptations like these in the clinic,” said co-author Dr. Mark Hewlett.
_____
C. Reding-Roman et al. 2017. The unconstrained evolution of fast and efficient antibiotic-resistant bacterial genomes. Nat. Ecol. Evol. 1: 0050; doi: 10.1038/s41559-016-0050
Source: http://www.sci-news.com/medicine/antibiotics-stimulate-bacterial-reproduction-04581.html
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Monday, June 1, 2026
Esomeprazole: The Generic Form Of Nexium Explained
Esomeprazole is the generic name of the medication sold under the brand name Nexium. Generic medications contain the same active ingredient at the same dose and strength as their brand name counterparts and must meet the same FDA standards for quality, purity, and bioequivalence. The development and approval of generic drugs play an important role in making effective treatments more accessible and affordable for patients. The hallmark symptoms of acid reflux are heartburn, described as a burning sensation in the chest that often worsens after eating or when lying down, and acid regurgitation, the sensation of acid or food coming back up into the throat or mouth. Other symptoms can include a chronic cough, hoarseness, sore throat, and difficulty swallowing. Identifying and modifying dietary and lifestyle triggers is an important part of managing acid reflux alongside medication. The pharmacological action of esomeprazole is the basis for its use in treating conditions within the category of acid reflux and heartburn treatment. Understanding the mechanism by which the active compound produces its therapeutic effects helps patients appreciate why the medication needs to be taken consistently and at the correct dose to achieve the best results. Switching between brand name and generic versions of a medication is generally considered safe when the products are bioequivalent, but patients should inform their doctor if they notice any differences in effect after a formulary change. Some patients with conditions requiring precise drug levels in the blood may be monitored more closely during transitions. For most patients, however, approved generics provide equivalent therapeutic benefit to the brand name product. The acid reflux and heartburn treatment section on acid reflux and heartburn treatment covers both brand name and generic treatment options, giving patients a complete picture of what is available. Cost, insurance coverage, and pharmacy availability are practical factors to discuss with a pharmacist when filling a prescription for esomeprazole.
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