We're unable to sign you in at this time. Please try again in a few minutes.
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
Original Investigation |

Antibiotic Resistance Among Ocular Pathogens in the United States Five-Year Results From the Antibiotic Resistance Monitoring in Ocular Microorganisms (ARMOR) Surveillance Study

Penny A. Asbell, MD, MBA1; Christine M. Sanfilippo, PhD2; Christopher M. Pillar, PhD3,4; Heleen H. DeCory, PhD2; Daniel F. Sahm, PhD3,5; Timothy W. Morris, PhD6,7
[+] Author Affiliations
1Cornea Services, External Disease, and Refractive Surgery, Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, New York
2Bausch & Lomb, Rochester, New York
3Eurofins Medinet, Chantilly, Virginia
4currently with Micromyx, LLC, Kalamazoo, Michigan
5currently with IHMA, Inc, Schaumburg, Illinois
6Bausch & Lomb, Rochester, New York
7currently with Actelion Clinical Research, Cherry Hill, New Jersey
JAMA Ophthalmol. 2015;133(12):1445-1454. doi:10.1001/jamaophthalmol.2015.3888.
Text Size: A A A
Published online

Importance  The Antibiotic Resistance Monitoring in Ocular Microorganisms (ARMOR) study is the only ongoing nationwide antibiotic resistance surveillance program specific to ocular pathogens.

Objective  To report resistance rates and trends among common ocular isolates collected during the first 5 years of the ARMOR study.

Design, Setting, and Participants  This antibiotic resistance surveillance study was performed at an independent central laboratory. Clinical centers across the United States were invited to submit ocular isolates of Staphylococcus aureus, coagulase-negative staphylococci (CoNS), Streptococcus pneumoniae, Haemophilus influenzae, and Pseudomonas aeruginosa. Isolates were collected from January 1, 2009, through December 31, 2013, and analyzed from January 16 to May 15, 2015.

Main Outcomes and Measures  Minimum inhibitory concentrations for various antibiotic classes were determined by broth microdilution according to the guidelines of the Clinical and Laboratory Standards Institute. Minimum inhibitory concentrations were interpreted as susceptible, intermediate, or resistant based on established break points.

Results  A total of 3237 ocular isolates (1169 S aureus, 992 CoNS, 330 S pneumoniae, 357 H influenzae, and 389 P aeruginosa) were collected from 72 centers. Methicillin resistance was found among 493 S aureus isolates (42.2%; 95% CI, 39.3%-45.1%) and 493 CoNS isolates (49.7%; 95% CI, 46.5%-52.9%), and methicillin-resistant (MR) isolates had a high probability of concurrent resistance to fluoroquinolones, aminoglycosides, or macrolides (P < .001). Multidrug resistance to at least 3 additional antibiotic classes was found in 428 MR S aureus isolates (86.8%) and 381 MRCoNS isolates (77.3%). All staphylococcal isolates were susceptible to vancomycin. Resistance among S pneumoniae isolates was highest for azithromycin (113 isolates [34.2%]) whereas resistance among P aeruginosa and H influenzae was low against the antibiotics tested. Staphylococcal isolates from elderly patients were more likely to be MR, as were S aureus isolates obtained from the southern United States (P < .001). Methicillin resistance among staphylococci did not increase during the 5-year study period (P ≤ .22), and small decreases in resistance to ciprofloxacin among CoNS and MRCoNS and to tobramycin among CoNS (P ≤ .03) were found.

Conclusions and Relevance  Methicillin resistance was prevalent among staphylococcal isolates from ocular infections, with many strains demonstrating multidrug resistance. These findings are consistent with resistance trends reported for nonocular staphylococcal isolates. Overall ocular resistance did not increase during the 5-year study period. Continued surveillance of ocular isolates provides critical information to guide selection of topical antibacterials used for empirical management of ocular infections.

Figures in this Article


Place holder to copy figure label and caption
Figure 1.
Concurrent Resistance to Other Antibiotic Classes Among Ocular Isolates by Methicillin Resistance Status

MR indicates methicillin resistant; MS, methicillin susceptible.

Graphic Jump Location
Place holder to copy figure label and caption
Figure 2.
Multidrug Resistance

Isolates were tested against ciprofloxacin, azithromycin, clindamycin, chloramphenicol, tobramycin, ceftriaxone, imipenem, oxacillin, vancomycin, and trimethoprim. The percentage of resistance includes intermediate resistance. CoNS indicates coagulase-negative staphylococci.

Graphic Jump Location
Place holder to copy figure label and caption
Figure 3.
Resistance Among Ocular Isolates by Patient Age

Data are expressed as mean (SE) percentage of resistance (black line) and percentage of methicillin resistance (blue line) by decade of life. P values are calculated using analysis of variance of the mean percentage of resistance.

Graphic Jump Location
Place holder to copy figure label and caption
Figure 4.
Resistance Among Ocular Isolates by Antibiotic Class During the 5-Year Study Period

Decreases were found in full and intermediate resistance to ciprofloxacin among coagulase-negative staphylococci (CoNS) (P = .002) and methicillin-resistant CoNS isolates (P = .02) and to tobramycin among CoNS isolates (P = .03).

Graphic Jump Location





You need to register in order to view this quiz.


Some tools below are only available to our subscribers or users with an online account.

2 Citations

Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

Related Content

Customize your page view by dragging & repositioning the boxes below.

Articles Related By Topic
Related Collections
PubMed Articles