Study offers insight on antibiotics

The antibiotics studied belong to the rifamycin family. Until now, researchers believed that these antibiotics and their derivatives, of which there are at least a thousand, all killed bacteria in the same way.

The new study shows that these drugs remove a key component of the bacteria they attack. Furthermore, different rifamycins bring about this same result in slightly different ways.

The researchers from The Ohio State University used recent advances in X-ray imagery to obtain the highest resolution figures ever available of how rifamycins bind to their targets.

This technology allowed the investigators to propose a major revision in the understanding of how these antibiotics work and explains why bacteria that have developed resistance to one form of rifamycin may still be targeted by another.

“That may help to narrow down the search for new synthetic derivatives to conquer resistance altogether,” said Dr Irina Artsimovitch, study co-author and an assistant professor of microbiology at the university.

Rifamycins are what drug companies call “broad-spectrum antibiotics,” they act against a variety of pathogens. The drugs are relatively inexpensive to make, have a long shelf life and are nearly non-toxic to cells other than those they seek to target. The only flaw in the drugs is the rapid development of bacterial resistance.

If manufacturers could overcome this problem rifamycins would become a near-perfect drug; this research may provide the means for that development.

“From these findings we can suggest how rifamycins that are currently used in therapy can be improved to be effective even against existing resistant strains of bacteria,” said Dr Artsimovitch.