How antibiotic-resistant bacteria can be eliminated

A combination and sequence of antibiotics can effectively hinder the development of antibiotic-resistant bacteria, a study found.

Researchers at Moffitt Cancer Centre, Florida, have developed a novel mathematical method, inspired by Darwinian evolution, to use current antibiotics to eliminate or reduce the development of antibiotic-resistant bacteria.

It is estimated that each year in the US, two million people become infected with bacteria that are resistant to one or more types of antibiotics, and at least 23,000 people will die because of these infections.

The researchers showed that the ability of the bacterium E. coli to survive in antibiotics could be either promoted or hindered depending on the sequence of antibiotics given.

They discovered that approximately 70 percent of different sequences of 2 to 4 antibiotics lead to resistance to the final drug.

"Our results suggest that, through careful ordering of antibiotics, we may be able to steer evolution to a dead end from which resistance cannot emerge," said lead author Daniel Nichol from Moffitt.

One approach to fight antibiotic-resistant infections is by using different combinations or sequences of antibiotics.

However, given the high number of antibiotics in existence, it would be extremely difficult to experimentally identify the best combination or sequence of drugs.

Moffitt researchers overcame this problem by developing a novel mathematical approach to analyse antibiotic resistance.

"Our results can be easily tested in the laboratory, and if validated could be used in clinical trials immediately, as all of the compounds we studied are FDA-approved and commonly prescribed," said senior study author Jacob G. Scott.

The researchers explained that their results also serve as a caution to healthcare workers, as the careless or random prescription of drugs could lead to antibiotic resistance.

The problem is being exacerbated by overuse of antibiotics for livestock and also in community clinical practice.