ARMOR study evaluates antibiotic resistance in the treatment of staph infections

Penny Asbell, MD, FACS, MBA, discusses “Antibiotic Resistance among Ocular Staphylococcal Pathogens: Longitudinal Trends in the ARMOR Study."

This transcript has been edited for clarity.

One of the worst things that can happen for a clinician is somebody with an infection, particularly if it's something you did surgery or you fit the contact lens. Whether it's a keratitis ophthalmitis, we really don't want it. And what we best want to do is treat it quickly and as best we can right away.

One of the things that I'm talking about today is the ARMOR study. It's a surveillance study in the United States of ocular isolates. We've been doing it since 2009, so we have data over a decade, and I'm specifically talking today about staph infections.

We saw over 3000 isolates of staph aureus, and nearly 2000 isolates of coagulase-negative staph, including Staph epidermidis.

We continue to see a significant amount of methicillin-resistant staph. So in the staph aureus side, it's changed a little bit, it did go down from 39%, to about 37%. And in the coagulase-negative side, it also went down — [it] was over 50%, now it's down to 37%.

The take home message for you — for us as clinicians — is that 40% of the staph, whether it's staph aureus, coagulase-negative staph, is methicillin-resistant.

Now, what does that mean? Well, if it's methicillin-resistant, when we test it against other antibiotics, it turns out to be multidrug resistant. So over 80% of the methicillin-resistant organisms are resistant to three other classes of organisms. So we really have to think carefully and wisely about how to pick an antibiotic.

The key thing is a patient comes in, we make the diagnosis pretty quickly, and we really want to get treatment started almost right away. Yes, we're probably going to get a culture or maybe even PCR to improve our diagnosis, but we really want to treat them right then and there. And that's where taking a look at the MICs, which is the laboratory way of looking at potency of antibiotics, really gives us some good information. ...

Obviously, you'll adjust your treatment depending on the culture results, resistance information that you get, but if we really want to get started right away, we'd have to pick an antibiotic.

I think the ARMOR study as a surveillance study of organisms in the United States is a great way to get your foot in the door as you begin treating these serious problems.

We look forward to sharing more information. This study is sponsored by B&L. I have no financial interest in the study, but I'm glad to share the results with you and look forward to sharing more results as we go forward.