1370. Role of Clindamycin Versus Linezolid for Serious Group A Streptococcal Infections

BACKGROUND: Streptococcus pyogenes can cause severe illnesses such as toxic-shock syndrome and necrotizing fasciitis due to pyrogenic exotoxins. Clindamycin is added to penicillin for treatment of severe S. pyogenes infections as it is a bacterial protein synthesis inhibitor which reduces toxin production. However, clindamycin is associated with several adverse effects including C. difficile infection. Linezolid is a bacterial protein synthesis inhibitor that has been shown to provide excellent coverage of S. pyogenes including toxin inhibition in vitro, but clinical evidence is lacking. We compared outcomes of patients treated with linezolid versus clindamycin for serious S. pyogenes infections. METHODS: This was a retrospective study of patients with necrotizing fasciitis or toxic shock syndrome caused by S. pyogenes admitted to the Shock Trauma Center at University of Maryland Medical Center treated with at least 48 hours of either clindamycin or linezolid. Data collected included Sequential Organ Failure Assessment (SOFA) and Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) severity scores, time to resolution of infection, number of surgeries, C. difficile infection, other antibiotic associated adverse effects, and mortality. Associations between patient characteristics, antibiotic groups, and outcomes were analyzed using the chi-square test, Fisher’s exact test and t-test or Wilcoxon rank-sum test as appropriate (SAS v 9.4). RESULTS: 52 patients were included, 26 treated with clindamycin and 26 with linezolid. Most patients (85% clindamycin and 96.2% linezolid) were treated for necrotizing fasciitis. Baseline characteristics, including SOFA and LRINEC scores, were similar between the groups. There was no difference in mortality between patients treated with clindamycin versus linezolid (11.5% vs. 7.7%, p = 0.22), and resolution of infection was similar between the groups (92.3% vs. 88.5%, p = 1.0). There was no difference in adverse effects between the clindamycin and linezolid groups, including C. difficile infection (3.9% vs. 0% p = 1.0) and thrombocytopenia (30.8% vs. 42.3%, p = 0.4). CONCLUSION: Linezolid could be an alternate to clindamycin for the treatment of serious toxin producing S. pyogenes infections. Further prospective studies are needed. DISCLOSURES: Emily Heil, PharmD, MS, BCIDP, Nothing to disclose