Pseudomonas aeruginosa, Staphylococcus aureus, and fluoroquinolone use

Area of Science:

• Infectious Diseases
• Hospital Epidemiology
• Antimicrobial Stewardship

Background:

• Long-term, multicenter studies on aggregate antimicrobial drug use and bacterial resistance are limited.
• Understanding the link between hospital antimicrobial use and resistance is crucial for infection control.
• Fluoroquinolones are a critical class of antibiotics used in healthcare settings.

Purpose of the Study:

• To investigate the relationship between aggregate fluoroquinolone use and the prevalence of fluoroquinolone-resistant bacteria in US hospitals over a five-year period.
• To analyze trends in resistance for Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA).

Main Methods:

• Data on fluoroquinolone use were collected from a network of US hospitals between 1999 and 2003.
• Yearly antibiograms were used to determine the percentages of fluoroquinolone-resistant Pseudomonas aeruginosa and MRSA.
• Statistical analyses included univariate linear regression and generalized estimating equations (GEE) for longitudinal modeling.

Main Results:

• Univariate analysis indicated significant associations between fluoroquinolone use and resistance rates for P. aeruginosa (1999-2001) and S. aureus (1999-2002).
• Longitudinal modeling using GEE did not reveal significant effects of fluoroquinolone use on resistance for most drug-organism pairs.
• An exception was the significant relationship found between levofloxacin use and increased MRSA resistance.

Conclusions:

• The ecological relationship between aggregate fluoroquinolone use and bacterial resistance is complex and not consistently linear over time.
• While initial associations were observed, advanced longitudinal analysis suggests a more nuanced impact, with levofloxacin and MRSA being a notable exception.
• Further research is needed to fully elucidate the dynamics of antimicrobial use and resistance development in hospital environments.