Ask the Expert: How can we address antibiotic resistance?

Professor Chris Calderone in a chemistry labProfessor Chris Calderone in a chemistry lab

Since the discovery of antibiotics—most famously, Alexander Fleming’s serendipitous identification in 1928 of penicillin on a contaminated Petri dish—countless lives have been saved from infections. Though antibiotics underpin modern medicine, we cannot take them for granted. In fact, the very nature of antibiotics necessitates that their effectiveness has an expiration date. The same process of evolution and natural selection that Charles Darwin described in the 19th century has led to a crisis in antibiotic resistance.

An infection consists of millions of bacterial cells, some of which have random mutations in their genomes. And some of those random mutations, in turn, may confer resistance to a particular antibiotic—say, penicillin—to the bacteria that bear them. Now imagine what happens when we try to treat an infection with penicillin. Those bacteria without the mutation die, and those with the mutation thrive. Eventually, as the resistant bacteria multiply, they spread and infect other hosts who can no longer be treated effectively with penicillin.

Even more concerning is the concept of horizontal gene transfer. Put simply, it is possible for the DNA encoding mutations to be transferred from one bacterium to another. Thus, once evolution “finds” a resistance-conferring mutation, it can spread rapidly among bacteria, transforming formerly sensitive strains of bacteria into antibiotic-resistant ones.

Researchers around the world are taking several approaches to antibiotic resistance. One strategy is to take formerly effective antibiotics and “tweak” their structures—for example, chemically converting penicillin into amoxicillin. Other scientists are looking for new classes of antibiotics. For example, in 2015 scientists discovered a particularly promising antibiotic candidate known as teixobactin, which has a completely novel form of antibiotic activity and no observed bacterial resistance (for now!).

Regardless of the scientific community’s best efforts, though, antibiotic resistance is a looming public health crisis. Because of the relentless and inevitable process of evolution, this is a problem we can never truly solve—only postpone.

Add a comment

The following fields are not to be filled out. Skip to Submit Button.
(This is here to trap robots. Don't put any text here.)
(This is here to trap robots. Don't put any text here.)
(This is here to trap robots. Don't put any text here.)