391. Clindamycin Susceptibility of Methicillin-Resistant Staphylococcus aureus Varies by Epidemiology and Infectious Process
Session: Poster Abstract Session: MRSA, MSSA, Enterococci
Thursday, October 3, 2013
Room: The Moscone Center: Poster Hall C
Posters
  • Clindamycin Susceptibility_LiA.pdf (268.2 kB)
  • Background: Currently, antibiograms use aggregate data to determine local susceptibility of organisms; an antibiogram based on disease state may help highlight the differences in MRSA susceptibility and better guide empiric antibiotic therapy. The primary objectives were to create antibiograms based on clinical manifestations and epidemiological group for MRSA isolates. The secondary objectives were to determine susceptibility patterns of isolates according to hospital location, patients who are immunosuppressed, and patients transferred from an outside facility.

    Methods: This was a retrospective and descriptive study. The first culture obtained from each site for each patient and that were obtained from Children’s Mercy Main and South campus were included. Cultures obtained from cystic fibrosis patients and surveillance nasal swabs were excluded. Isolates were identified through the clinical microbiology laboratory information system and then cross referenced with ICD-9 codes for clinical manifestations and patient history to determine epidemiologic group, infectious process, and medical history. Patient profiles were reviewed to collect the following data: patient location, transfer history, and medical history.

    Results:

    865 MRSA isolates were reviewed from 2011. Only clindamycin susceptibility varied in comparison to the hospital antibiogram and by epidemiological category and clinical manifestation.

     

     Category

    Total

    Clindamycin

    Institutional antibiogram

    All MRSA isolates

    1171

    87%

    Clinical Manifestation

    SSTI

    785

    90%

    Pulmonary

    20

    50%

    Bone/Joint

    14

    79%

    Bacteremia

    7

    57%

    Other

    39

    51%

    Epidemiological Group

    CA- MRSA

    668

    91%

    HA-MRSA-CO

    163

    78%

    HA-MRSA-HO

    34

    44%

    Location

    PICU

    10

    40%

    NICU

    4

    75%

    General Pediatrics

    139

    78%

    Emergency Department

    440

    92%

    Immune status

    Immunocompromised

    23

    72%

    Immunocompetent

    842

    87%

    Residence at time of admission

    Private Residence

    842

    87%

    Transfer from OSH

    23

    70%

    Conclusion: Clindamycin susceptibility of MRSA differs when categorized by clinical manifestation and epidemiology, thus a specific antibiogram in addition to the general antibiogram may help guide empiric antibiotic therapy for MRSA. Recommendations for the development of categorical antibiograms are needed.

    Amanda Li, PharmD1,2, Diana Yu, PharmD, BCPS3, Richard Ogden, Jr., PharmD4, Rangaraj Selvarangan, PhD2 and Brandon French, PharmD, BCPS1,2, (1)Pharmacy, Children's Mercy Hospital and Clinics, Kansas City, MO, (2)Children's Mercy Hospital and Clinics, Kansas City, MO, (3)Children's Mercy Hospitals and Clinics, Kansas City, MO, (4)Children's Mercy Hospital, Kansas City, MO

    Disclosures:

    A. Li, None

    D. Yu, None

    R. Ogden, Jr., None

    R. Selvarangan, None

    B. French, None

    Findings in the abstracts are embargoed until 12:01 a.m. PST, Oct. 2nd with the exception of research findings presented at the IDWeek press conferences.