Multicenter Observational Study on Factors and Outcomes Associated with Various Methicillin-Resistant Staphylococcus...

Area of Science:

• Infectious Diseases
• Microbiology
• Pulmonology

Background:

• Methicillin-resistant Staphylococcus aureus (MRSA) prevalence is rising in cystic fibrosis (CF) patients.
• Approximately 30% of MRSA strains in CF patients are SCCmec IV type (e.g., USA300), differing from SCCmec II strains.

Purpose of the Study:

• To investigate if risk factors for MRSA acquisition and subsequent outcomes differ between healthcare-associated (SCCmec II) and community-associated (SCCmec IV) MRSA strains in CF patients.
• To determine the role of SCCmec type and Panton-Valentine leukocidin (PVL) in MRSA infections within this population.

Main Methods:

• MRSA isolates from pediatric CF patients at seven centers were typed for SCCmec type and PVL.
• Data from the CF Patient Registry were used to assess risk factors and clinical outcomes.
• Analysis compared patients with SCCmec II, SCCmec IV PVL(-), and SCCmec IV PVL(+) strains.

Main Results:

• SCCmec IV strains increased in prevalence from 1996-2010.
• SCCmec II strains were associated with Pseudomonas aeruginosa-positive cultures and increased clinic visits.
• Hospitalizations increased in SCCmec IV PVL(-) strains compared to PVL(+) strains, while lung function and anthropometrics remained stable post-detection.

Conclusions:

• Healthcare exposure and P. aeruginosa may be risk factors for SCCmec II MRSA acquisition in CF patients.
• Clinical interventions and CF care increased after MRSA detection, irrespective of SCCmec type.
• Understanding strain-specific differences is crucial for managing MRSA in CF.