1072. Outcomes of Methicillin Susceptible Staphylococcus aureus Blood Stream Infections with Various Beta-Lactam Therapy
Session: Poster Abstract Session: Clinical Infectious Diseases: Bacteremia and Endocarditis
Friday, October 28, 2016
Room: Poster Hall
  • MSSA Poster_IDWeek_10.20.16_FINAL.pdf (87.9 kB)
  • Background: Staphylococcus aureus blood stream infections (BSIs) are associated with significant mortality and healthcare costs. Methicillin sensitive S. aureus (MSSA) BSIs may be treated with cefazolin or an anti-staphylococcal penicillin as first-line options (standard therapy [ST]); however, other agents with reported susceptibility may also be considered for use based on convenience of dosing, concomitant infecting organisms, or patient allergies. The purpose of this study was to evaluate the comparative efficacy of ST versus other beta-lactam therapy (OBT) in treating MSSA BSIs.

    Methods: This was a retrospective, cohort study of patients with MSSA BSIs treated with beta-lactam antibiotics as definitive therapy at an academic medical center between January 2012 and December 2014. Patients > 18 years of age at time of culture treated with definitive beta-lactam therapy for at least 48 hours were included in two groups: ST or OBT. The primary outcome was time to microbiological cure, measured as time to negative blood cultures. Secondary outcomes included infection recurrence, hospital length of stay, intensive care unit (ICU) length of stay, and inpatient mortality.

    Results: 98 patients were included in this study: 73 in the ST group and 25 in the OBT group. Baseline demographic data was similar between groups. The primary outcome of time to negative blood cultures was not statistically significantly different between groups (2 days vs 3 days; p=0.16). Patients in the ST group had statistically significantly shorter median ICU length of stay than patients in the OBT group (3 days vs. 12 days, p=0.02). There was significantly lower all-cause in-house mortality in the ST group with 2 deaths compared to 5 deaths in the other OBT group (p=0.01).There was no statistically significant different between groups with regard to infection recurrence and length of hospital stay (p=0.42, p=0.29, respectively).

    Conclusion: For patients with MSSA BSIs, ST and OBT showed similar time to negative blood cultures. ST was associated with significantly shorter ICU length of stay and reduced in-house mortality. Future studies are needed to determine the contribution of specific non-ST beta-lactam agents to the outcomes of interest.

    Ashley Gale, PharmD1, Milena M. Mclaughlin, PharmD, MSc1,2, Viktorija O. Barr, PharmD1,3, Hankyung Cho, PharmD Candidate2, Michael Postelnick, BS Pharm1 and Elise M. Gilbert, PharmD1,4, (1)Northwestern Memorial Hospital, Chicago, IL, (2)Midwestern University Chicago College of Pharmacy, Downers Grove, IL, (3)Rosalind Franklin University College of Pharmacy, North Chicago, IL, (4)College of Pharmacy, Chicago State University, Chicago, IL


    A. Gale, None

    M. M. Mclaughlin, None

    V. O. Barr, None

    H. Cho, None

    M. Postelnick, None

    E. M. Gilbert, None

    Findings in the abstracts are embargoed until 12:01 a.m. CDT, Wednesday Oct. 26th with the exception of research findings presented at the IDWeek press conferences.