Original article
Ocular TRUST: Nationwide Antimicrobial Susceptibility Patterns in Ocular Isolates

https://doi.org/10.1016/j.ajo.2008.01.025Get rights and content

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.

Section snippets

Prospective Surveillance Study (Ocular Trust 1)

In the prospective surveillance study conducted from October 2005 through June 2006, S. aureus, S. pneumoniae, and H. influenzae isolates from ocular infections were collected by seven eye hospitals and 28 community hospitals in 19 states. The site of ocular infection was not specified. In vitro antimicrobial susceptibility testing was conducted by a central laboratory (Eurofins Medinet, Inc; Anti-infective Services, Herndon, Virginia, USA). Quality control measures included laboratory coding

Ocular Trust 1

Participating centers submitted 197 S. aureus, 49 S. pneumoniae, and 32 H. influenzae isolates from ocular infections between October 2005 and June 2006. Among S. aureus isolates (Table 2), 164 (83.2%) were MSSA and 33 (16.8%) were MRSA. Susceptibility patterns were virtually identical for the fluoroquinolones in MSSA and MRSA. Although fluoroquinolones were active against MSSA, most MRSA isolates exhibited high-level resistance to the class. MRSA also was highly resistant to the other drugs

Discussion

Ocular TRUST was initiated in 2005 to 2006 as the first nationwide longitudinal surveillance program to monitor antimicrobial susceptibility of pathogens isolated from ocular infections. We report the results of Ocular TRUST 1, the inaugural study evaluating in vitro susceptibility of S. aureus, S. pneumoniae, and H. influenzae to a panel of antimicrobials with differing mechanisms of action. These data, together with longitudinal data from more than 1000 archived S. pneumoniae and H. influenzae

Dr Penny A. Asbell is a Professor of Ophthalmology, a Director of Cornea and Refractive Services, and a Cornea Fellowship Director in the Department of Ophthalmology at Mount Sinai School of Medicine, New York, New York. An internationally renowned physician-scientist specializing in diseases of the cornea, Dr Asbell's clinical and translational research have lead to new treatments for ocular herpes and dry eye disease and to new surgical procedures for refractive surgery, keratoconus, and

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    • Cited by (0)

    Dr Penny A. Asbell is a Professor of Ophthalmology, a Director of Cornea and Refractive Services, and a Cornea Fellowship Director in the Department of Ophthalmology at Mount Sinai School of Medicine, New York, New York. An internationally renowned physician-scientist specializing in diseases of the cornea, Dr Asbell's clinical and translational research have lead to new treatments for ocular herpes and dry eye disease and to new surgical procedures for refractive surgery, keratoconus, and corneal translation.

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