Antibiotic dilemmas amid increased resistance

Why has antimicrobial resistance (AMR) become a global threat?

Jean Patel: I’ve spent a career watching the epidemiology of AMR, and it just spreads easily. It can amplify within a patient and then it can spread from one patient to another. So now we have hard-to-treat infections all over the world.

Eric Myers: I think a lot can be attributed to travel. Global travel is a lot more prevalent now than it used to be. So, when we get some of these novel resistance mechanisms that can be passed via plasmid, they’re able to spread all over the place a lot more quickly than maybe 40 or 50 years ago.

Navaneeth Narayanan: A lot of our antibiotics are derivative of natural compounds and bacteria have been exposed to that for millions of years. So, they have a pretty good head start on developing resistance.

Could you address the intrinsic link between diagnostics stewardship and antimicrobial stewardship?

EM: Diagnostic stewardship is one of those things that, historically, antibiotic stewardship programmes have not paid enough attention to, but thankfully that’s changing. We’re starting to emphasise it a lot more. But you really can’t have an effective antibiotic stewardship programme without diagnostic stewardship.

Providers will often reflexively treat a positive culture. Even if the patient doesn’t necessarily have symptoms consistent with infection, once they’re staring that positive culture in the face it becomes almost impossible to convince them not to treat it. Especially if it’s a very resistant organism as the fear level goes up. The most effective way to prevent some of that is to not get the culture to begin with. We think of urine cultures in this, treatment of asymptomatic bacteriuria. But other culture sites such as sputum cultures and blood cultures are contaminated fairly often. That leads to more vancomycin use, and so on. Being good stewards of our cultures and diagnostics is important for antibiotic stewardship.

NN: I’ll add that getting the right specimens is important. Is it a tissue specimen from the operating room that might tell you something more about the pathogen, or is it a swab of the skin around the wound site where several organisms will be picked up whether there’s an infection or not? This might not help you, but just cloud the picture. So, using diagnostics in the appropriate way is key. Then on the flip side, making sure that you try to access novel, helpful diagnostics for the right patient populations. All of this mitigates upstream issues rather than letting the issues get out and having to deal with it on the back end with trying to limit how much antibiotics are being overused in an appropriate way.

JP: There are examples of healthcare settings which have written treatment guidelines based upon the diagnostics used in their institution. And this can be very specific. They know what kind of results a doctor would get, and you can teach doctors to use the antibiotics based upon a very specific test result. I think those kinds of treatment guidelines are really helpful.

NN: We’ve done that for some of our rapid diagnostics from blood cultures, depending on the resistance that’s found and what we would recommend in general. Then we even provide decision support as a stewardship team to help support those general guidelines that we provide.