1118. Comparative Evaluation of the Antimicrobial Susceptibility Patterns of Community- and Hospital-Acquired Methicillin-Resistant S. aureus (MRSA) from USA Hospitals by Site of Infection: Results from the Ceftaroline Surveillance Program AWARE (2012-2014)
Session: Poster Abstract Session: MRSA/VRE Epidemiology
Friday, October 9, 2015
Room: Poster Hall
Posters
  • IDWeek15 Ceftaroline CA HA-MRSA 1118.pdf (133.8 kB)
  • Background: MRSA has been increasingly identified as a cause of community-onset infections. Although the initial community-acquired (CA)-MRSA strains were more susceptible (S) to antimicrobial agents compared to traditional hospital-acquired (HA)-MRSA strains, CA-MRSA variants with multidrug resistance patterns have been increasingly reported.

    Methods : Among 8,437 MRSA strains collected through the ceftaroline (CPT) AWARE program (2012-2014), 7,116 and 1,321 were reported as CA- and HA-MRSA, respectively. Organisms were collected from 145 medical centers in the USA and tested for S against CPT and comparators by the broth microdilution method.

    Results: CA-/HA-MRSA were isolated mainly from patients with skin and skin structure infections (SSSI; 68.4/27.0%), pneumonia (13.7/49.0%) and bacteremia (10.0/17.7%). Overall, S rates were generally lower among HA-MRSA compared to CA-MSA strains (Table), especially for clindamycin (CLI; 61.4 vs. 76.6%) and levofloxacin (LEV; 21.4 vs. 35.5%). CPT was active against 98.0% of CA-MRSA and 94.3% of HA-MRSA (MIC50/90, 1 μg/mL for both) overall, with little variation among infection type subsets. Among SSSI and bacteremia isolates, S rates for CLI and LEV were lower among HA-MRSA compared to CA-MRSA. Further, S rates among isolates from pneumonia were generally lower compared to isolates from SSSI and bacteremia. Tetracycline (TET) and trimethoprim/sulfamethoxazole (T/S) exhibited good in vitro activity against CA- and HA-MRSA from all infection types. Erythromycin (ERY) S was generally low.

    Conclusion: CPT exhibited potent in vitro activity against CA- and HA-MRSA isolates independent of infection type. S rates were generally lower among HA-MRSA and varied according to the type of infection.

    Helio S. Sader, MD, PhD, David J. Farrell, PhD, Rodrigo E. Mendes, PhD, Robert K. Flamm, PhD and Ronald N. Jones, MD, JMI Laboratories, Inc., North Liberty, IA

    Disclosures:

    H. S. Sader, Actavis: Research Contractor , Research support

    D. J. Farrell, Actavis: Research Contractor , Research support

    R. E. Mendes, Actavis: Research Contractor , Research support

    R. K. Flamm, Actavis: Research Contractor , Research support

    R. N. Jones, Actavis: Research Contractor , Research support

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 7th with the exception of research findings presented at the IDWeek press conferences.