According to Penny Asbell, MD, FACS, MBA, the Antibiotic Resistance Monitoring in Ocular Microorganisms (ARMOR) surveillance study has identified high levels of in vitro antibiotic resistance among ocular staphylococcal and pneumococcal pathogens, resistance that may affect treatment success. She discussed the program at the American Academy of Ophthalmology’s 2022 annual meeting in Chicago.
Note: This transcript has been lightly edited for clarity.
Penny Asbell, MD, FACS, MBA, University of Tennessee Health Science Center:
Hello, I'm really glad to be here today. You know, I'm just like you. In walks in a patient with this serious infection, they got a corneal ulcer, and I've got to figure out how to treat them. Now, you may want to go to fortified antibiotics, but no matter where you are, it's going to take some time to get that organized.
So one of the things about the ARMOR study is this can give you some idea of where to get started. ARMOR collects isolates from throughout the United States. Over the last decade, it has included over 100 sites in 31 states, and we have over 8,000 isolates. So it's a huge sample, and it has really good results to help us get going.
So what can we tell them what we can use from it in terms of picking an antibiotic? Let's take a look at staph. You know, staph infections are very common, not just for conjunctivitis, but ended up to endophthalmitis and keratitis. And when you look at the keratitis samples, we have almost 2,000 of them on nearly a third of the staph aureus are methicillin resistant. And when you look at the coagulase, negative staph, you get over 40% are methicillin resistant. So that's kind of the bad news with a little bit more bad news.
Once they're methicillin resistant 80% Over 80% of them are multi drug resistant. So even if we picked that first antibiotic, we may not do too well with a second third, or other antibiotic choices. So we've got to keep that in mind.
Even when we think of an antibiotic is “broad spectrum,” it very well may not cover one of the leading organisms that can cause serious infections. The good news is if we look at our data over the last decade, we actually do see a trend of decreasing resistance a little bit. It's a couple of percentage points that is in the right direction, or remember, resistance is still there.
And one of the ways to pick is looking at an MIC-90, as you recall, that's a laboratory tests looking at the potency of the antibiotic for that specific organism. And if you look at all the ciprofloxacin in Florida, including azithromycin, and the other ones that are commercially available here, the azithromycin is very competitive to vancomycin. Vancomycin, of course, is great, but it's not off the shelf, you can kind of get the patient going with an antibiotic that seems like it's going be good until your cultures get going.
So, it gives you an opportunity to figure out how to get going, start treating the patient right away even in the office, while your cultures are pending. And maybe if you decide on four or five while they're pending as well. So, we want those patients to get better at it, especially if we're the ones who operated on the patient or fitted the contact lens. But in any case, treat those infections, get them better and use ARMOR to help you at least with that initial decision making.