emory-wire

Expert Q&A: The Antibiotic Resistance Threat

"We're seeing the steady emergence of resistance to antibiotics that were once dependable," says Monica Farley, principal investigator for the Georgia Emerging Infections Program.

By Quinn Eastman

Monica Farley is principal investigator for the Georgia Emerging Infections Program. She is an Emory professor of medicine in infectious disease, a physician at the Atlanta VA Medical Center, and a faculty researcher at the Emory Antibiotic Resistance Center.

Topics in this article:

How does antibiotic resistance change the decisions you make as a doctor?

It's changing the playing field. Isolating bacteria and testing them for antibiotic resistance can sometimes take 24 to 48 hours—too long to wait if someone is sick and needs treatment. We have to make a good guess before we know the results. Twenty years ago, if someone had a suspected staph infection in a cut on their leg, we could assume it would be treatable with cephalosporin or something similar. Now we can't really say that. We have to assume it will be MRSA. It also means we have to treat many more infections with vancomycin, which is now standard for MRSA-type infections. Vancomycin is a compromise, because it doesn't work as fast as the drugs we would have used in the past.

It's the same for pneumonia. If someone develops pneumonia in the hospital, we have to assume it's a bad bug. We can't use the same drug we'd use for someone just coming in from the community. It's also influenced how we treat meningitis. Now we usually need more than one drug, maybe even three.

If the lab tells us we can use one of the older drugs, we will switch back. But we have to assume we're dealing with a resistant infection, unless proven otherwise, in hospital settings. The antibiotics that are left are often the ones we least want to use—ones that are more toxic or harder to tolerate.

Is colistin, which was in the news a lot last year because of emerging resistance, in that category?

That's right. Colistin attracted some attention because it's a drug of last resort. It was often used in the early days of antibiotics but was put on the shelf for decades because less toxic alternatives were developed. Now we've had to revisit it.

Voices
How is antibiotic resistance going to affect medicine?

Around the time I was starting my career (in the 1980s), there was a declaration that infectious disease as a specialty was going to end because we had effective antibiotics. Over the last few decades, everything has flipped and we're seeing the steady emergence of resistance to antibiotics that were once dependable. Common infections that are usually not very serious, like a scrape on the skin that gets infected, can be increasingly resistant and more difficult to treat. Importantly, this extends to more serious infections in the hospital setting, to people who would likely not have survived their infections in the pre-antibiotic era. Bone marrow transplants, solid organ transplants — we would not be able to do these successfully if we did not have effective antibiotics. This phenomenon is threatening the advances we have made in the last 50 years.

What areas of medicine are going to be affected the soonest?

This really affects all areas of medicine. Resistant infections are more likely to be seen in the health care environment. Certainly there are concerns for people who are immunocompromised, such as organ transplant patients or people undergoing chemotherapy for cancer. But it won't be limited to them. It will impact anyone with lots of medical problems. Patients who have experienced a stroke. Patients with long-term catheters in place, or in nursing homes. They tend to have a lot of antibiotic exposure. These are the patients in whom we may see persistent colonization with antibiotic resistant bacteria, leading to recurrent urinary tract infections, for example. 

Read the complete story here on the Emory News Center.