Fluoroquinolones and risk for methicillin-resistant Staphylococcus aureus, Canada

Area of Science:

• Infectious Diseases
• Clinical Microbiology
• Pharmacology

Background:

• Antimicrobial drug use is a known risk factor for Clostridium difficile-associated disease (CDAD).
• The role of specific antimicrobial classes in facilitating healthcare-associated methicillin-resistant Staphylococcus aureus (MRSA) colonization and infection requires further investigation.
• Understanding these associations is crucial for infection control and antimicrobial stewardship.

Purpose of the Study:

• To determine the association between antimicrobial drug receipt and healthcare-associated MRSA colonization and infection.
• To compare the impact of antimicrobial drugs on MRSA with their effects on methicillin-susceptible S. aureus infection and CDAD.
• To inform antimicrobial prescribing practices in healthcare settings.

Main Methods:

• Retrospective cohort study involving 7371 episodes of care in a Quebec hospital.
• Data collection on patient risk factors, including antimicrobial drug receipt.
• Cox regression analysis to calculate crude and adjusted hazard ratios (AHR).

Main Results:

• Fluoroquinolones were identified as the predominant risk factor for CDAD during a Quebec epidemic.
• Receipt of fluoroquinolones significantly increased the risk for MRSA colonization (AHR 2.57) and infection (AHR 2.49).
• The effect of antimicrobial drugs on MRSA colonization and infection was comparable to their effect on CDAD.

Conclusions:

• Antimicrobial drug selection, particularly fluoroquinolones, plays a significant role in facilitating MRSA colonization and infection.
• The findings underscore the importance of considering the impact on both MRSA and CDAD when choosing antimicrobial agents.
• Judicious use of antimicrobials is essential to prevent the emergence and spread of resistant pathogens and C. difficile.