Have you ever been plagued by an infection that felt as if it would never go away? They’re known as recurrent infections because of their unerring ability to outsmart the medicines intended to do them in. I am reminded of a colleague who developed a painful urinary tract infection (UTI) last year. After five or six days, it appeared to have gone, but in what was to become a recurring pattern, a UTI showed up again a month later, leading to another round of antibiotics. That course of antibiotics seemed to stop the infection, until, boom, a few weeks later, yet another infection developed. It took my friend months for complete recovery. We all know about the growing problem with antibiotic-resistant bacteria, but that’s notwhat was going on in this case.

There is now an explanation as to why these infections return again and again. And tantalizingly, there is a new study with mice that shows how a very common substance may help quickly resolve these infections the first time around.

Persistent, Not Resistant

The study I’m referring to was conducted by James Collins, PhD, professor of Biomedical Engineering at Boston University. He is a Howard Hughes Medical Institute investigator and recipient of a MacArthur Fellowship (sometimes called a MacArthur “genius grant”). But before we get to those findings, a bit of bacteria background is in order. Dr. Collins explains that while doctors studying infectious diseases have focused their attention on antibiotic-resistant bacteria for a number of years, it is only in the last few that they started paying attention to another type of bacteria that they’ve tagged as persistent bacteria. Here’s the difference — regular bacteria become resistant because they mutate genetically in response to an antibiotic, thus making it increasingly difficult to create drugs that will be successful in getting rid of them. Persistent bacteria, on the other hand, do not mutate but have a physiological ability to become dormant — in effect to go to sleep for a period of time. Familiar infections known to be associated with persistent bacteria include strep, tuberculosis, staph and many more.

When persistent bacteria are slumbering, they are invulnerable to antibiotics. This means that the medicine you take for an infection will wipe out the majority of the bacteria causing the illness, but not the few persisters, as they are called. Later, for reasons not yet understood, certain persisters activate and cause new infection — and require another round of antibiotics. Persisters are nothing if not canny adversaries… a few will continue to remain asleep and invulnerable, ready to “wake up” later.

Waking All Persisters

Now, if there were some way to rouse all of the infection-causing bacteria into an active state at the same time, one course of common antibiotics would wipe out the whole bunch. The challenge, then, is to find a substance that would wake them all — and this is where Dr. Collins’s research comes in. Dr. Collins discovered that if he added sugar to antibiotics, allpersisters were activated so that they could no longer evade the antibiotics. His finding was robust indeed — when he administered antibiotics with sugar through an IV to mice with E. coli bacteria, a common cause of UTIs, the antibiotics wiped out 99.9% of the persistent bacteria in just two hours, compared with eliminating none of the persistent bacteria in the mice whose antibiotic IV did not include sugar.

A Rare Win-Win?

The next step is to test the method with humans. Success, if it comes, could have important implications for treating resistant bacteria as well as persisters. It is quite possible that some cases of seemingly resistant bacteria are actually caused by persisters. Having a strategy to kill all persistent bacteria with just one round of antibiotics would dramatically reduce the usage of antibiotics, and that in turn would help slow development of resistant bacteria — a real (and rare) win-win in our ongoing fight against bacteria. Dr. Collins says that combining sugar with an antibiotic is such a simple potential treatment that he is hopeful human studies will move ahead quickly. Many questions must be answered — including whether there are persistent bacteria that would not be awakened by sugar… and whether sugar itself might worsen certain infections, for example, yeast infections. We’ll keep our eye on this research.