Is fluoroquinolone (FQ) resistance of Escherichia coli (E. coli) less than 10% in New York City?

Fluoroquinolone Resistance in E. coli in New York City

Based on available evidence, fluoroquinolone resistance in E. coli in New York City appears to be at or near the 10% threshold, making empirical fluoroquinolone use borderline appropriate and requiring careful consideration of local resistance patterns and individual patient risk factors. 1

National and Regional Resistance Data

The most relevant guideline data from the American Academy of Pediatrics indicates that fluoroquinolone resistance rates in E. coli were generally below 10% in most parts of North America, though there was a clear trend toward increasing resistance compared with previous years. 1

Specifically for geographically diverse U.S. institutions:

• The EMERGEncy ID NET network (11 university-affiliated institutions across the U.S.) documented E. coli fluoroquinolone resistance rates of approximately 5% overall 1
• However, in specific locations, outpatient resistance rates approached 10% 1
• Data from three large tertiary care children's hospitals showed ciprofloxacin resistance for E. coli ranging from 4% to 7% for 2010, with rates appearing stable over the preceding 3 years 1

Clinical Context and Interpretation

While New York City-specific data is not explicitly provided in the evidence, NYC would likely fall into the category of "specific locations" with higher resistance rates given:

• Urban centers typically demonstrate higher antimicrobial resistance 1
• The 2011 IDSA/ESMID guidelines note that fluoroquinolone resistance rates were still <10% in most parts of North America, but emphasize significant geographic variability 1

The answer to whether resistance is "less than 10%" in NYC is therefore equivocal—it likely hovers right around this threshold, making the distinction clinically marginal. 1

Risk Factors That Increase Resistance Likelihood

Even if community rates are near 10%, certain patient populations have substantially higher resistance rates:

• Recent fluoroquinolone use in past 6 months: OR 17.5 for resistance 2
• Recent hospitalization: OR 2.0 2
• Urinary catheter use: OR 3.1 2
• International travel in preceding 3-6 months significantly increases resistance risk 1

Multidrug Resistance Concerns

A critical caveat: fluoroquinolone-resistant E. coli isolates are frequently multidrug resistant, with only 10.8% resistant to ciprofloxacin alone. 3 Among fluoroquinolone-resistant strains:

• 79.8% resistant to ampicillin 3
• 66.5% resistant to trimethoprim-sulfamethoxazole 3
• 14% were ESBL-positive (compared to <1% of susceptible isolates) 2

Clinical Recommendation

For empirical treatment of suspected E. coli infections in NYC, fluoroquinolones remain marginally acceptable if local resistance is confirmed to be <10%, but alternative agents should be strongly considered in patients with any risk factors for resistance. 1 Nitrofurantoin, fosfomycin, and mecillinam maintain excellent activity (<10% resistance) across all North American regions and represent safer empirical choices. 1

The 10% threshold is clinically significant because guidelines generally recommend against empirical use of antimicrobials when local resistance exceeds this level. 1