Ocular TRUST: Nationwide Antimicrobial Susceptibility Patterns in Ocular Isolates

Asbell, Penny A.; Colby, Kathryn A.; Deng, Sophie; McDonnell, Peter; Meisler, David M.; Raizman, Michael B.; Sheppard, John D.; Sahm, Daniel F.

doi:10.1016/j.ajo.2008.01.025

« Previous Next »American Journal of Ophthalmology
Volume 145, Issue 6 , Pages 951-958.e1, June 2008

Ocular TRUST: Nationwide Antimicrobial Susceptibility Patterns in Ocular Isolates

Penny A. Asbell
- Mount Sinai School of Medicine, New York, New York
- Inquiries to Penny A. Asbell, Department of Ophthalmology, Mount Sinai School of Medicine, 1 Gustave L. Levy Place, Box 1183, New York, NY 10029
Kathryn A. Colby
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts
Sophie Deng
- Jules Stein Eye Institute, Los Angeles, California
Peter McDonnell
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, Maryland
David M. Meisler
- Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio
Michael B. Raizman
- New England Eye Center, Tufts University School of Medicine and Ophthalmic Consultants of Boston, Boston, Massachusetts
John D. Sheppard Jr
- Virginia Eye Consultants, Norfolk, Virginia
Daniel F. Sahm
- Eurofins Medinet, Inc, Anti-Infective Services, Herndon, Virginia.

Accepted 11 January 2008. published online 29 February 2008.

Purpose

Ocular Tracking Resistance in U.S. Today (TRUST) annually evaluates in vitro antimicrobial susceptibility of Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae to ciprofloxacin, gatifloxacin, levofloxacin, moxifloxacin, penicillin, azithromycin, tobramycin, trimethoprim, and polymyxin B in national samples of ocular isolates.

Design

Laboratory investigation.

Methods

Prospectively collected ocular isolates (197 S. aureus, 49 S. pneumoniae, and 32 H. influenzae) from 35 institutions and archived ocular isolates (760 S. pneumoniae and 356 H. influenzae) from 34 institutions were tested by an independent, central laboratory. Mean minimum inhibitory concentrations that would inhibit growth of 90% of the tested isolates (MIC₉₀) were interpreted as susceptible, intermediate, or resistant according to standardized breakpoints for systemic treatment. S. aureus isolates were classified as methicillin susceptible (MSSA) or methicillin resistant (MRSA).

Results

MSSA or MRSA susceptibility patterns were virtually identical for the fluoroquinolones, that is, MSSA susceptibility was 79.9% to 81.1% and MRSA susceptibility was 15.2%. Trimethoprim was the only agent tested with high activity against MRSA. All S. pneumoniae isolates were susceptible to gatifloxacin, levofloxacin, and moxifloxacin; 89.8% were susceptible to ciprofloxacin. H. influenzae isolates were 100% susceptible to all tested agents but trimethoprim. Ocular TRUST 1 data were consistent with the eight-year longitudinal sample of archived ocular isolates.

Conclusions

The fluoroquinolones were consistently active in MSSA, S. pneumoniae, and H. influenzae. After more than a decade of intensive ciprofloxacin and levofloxacin use as systemic therapy, 100% of ocular S. pneumoniae isolates were susceptible to gatifloxacin, levofloxacin, and moxifloxacin; nonsusceptibility to ciprofloxacin was less than 15%. High-level in vitro MRSA resistance suggests the need to consider alternative therapy to fluoroquinolones when MRSA is a likely pathogen.