New option for antibiotics

2005/01/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Medikuntza

How to remove antibiotic resistance from bacteria so the medicine can act as before? That is what the researchers wanted to achieve and in the end it seems they have succeeded. Researchers have identified a molecule that extracts the fragment of bacteria-resistant DNA.

Bacteria become resistant in different ways. They sometimes mutate where the drug is directed. Other times the bacteria produce a gene that neutralizes the drug. In one way or another, bacteria develop resistance, thus preventing the drug from damaging them.

This resistance is also transmitted, usually by plasmids. Plasmids are small fragments of spiral DNA that work apart from the genome of the organism and that easily spread from cell to cell.

Each antibiotic has a pathway to fight bacteria, but these pathways are divided into three large groups. Therefore, a plasmid with one or more resistant genes is easily able to neutralize most drugs.

Now, at the University of Illinois in the United States, they have discovered how to remove plasmids from DNA from resistant bacteria. They have used a molecule called apramycin. This molecule resembles a small part of RNA. It is associated with RNA chains that contain genetic information, thus avoiding plasmid duplication. The bacteria take the plasmid as a stranger and expel it.

Researchers have tested the apramycin molecule in the bacterium Escherichia coli, resistant to antibiotic anpiziline, and have shown that the bacteria lose the plasma that gives it resistance. Therefore, ampicillin antibiotic manages to eliminate the bacteria as in the beginning.

Apramycin is a fairly toxic molecule, so it cannot be used in clinical trials. However, as they now know their mechanism, researchers hope to use other molecules with the same effect.