1349. Institutional Antibiograms Are Insufficient to Guide Clindamycin Use in Pediatric Skin and Soft Tissue Infections

BACKGROUND: Clindamycin (CLN) is a common empiric antimicrobial for pediatric skin and soft tissue infections (SSTI) despite decreasing susceptibility of Staphylococcus aureus (SA) to CLN on institutional antibiograms. This study inquired whether institutional antibiograms are an accurate representation of susceptibility for these infections. It also attempted to find patient and infection characteristics associated with being clindamycin susceptible (CLN-S). METHODS: This was a retrospective chart review of children with community-acquired (CA) SA infections in 2016 and 2017. A Staphylococcus aureus antibiogram was created based on infection type. Various patient and infection characteristics were compared between CLN-S and clindamycin-resistant (CLN-R) isolates to identify predictors of being CLN-S via binary logistic regression. Characteristics with p < 0.2 from a univariate analysis (chi-square or Fisher’s exact test) were included in the regression; p < 0.05 after the regression was considered statistically significant. RESULTS: 362 SA infections were included. These were 76% CLN-S, similar to the institutional antibiogram (79% CLN-S, p = 0.168). MSSA CLN susceptibility was lower than the antibiogram (71% vs. 79% CLN-S, p = 0.042). MRSA susceptibility was similar (79% vs. 80% CLN-S, p = 0.859). Infection types assessed were abscess (n = 264, 81% CLN-S), osteomyelitis (n = 40, 75% CLN-S), lymph node (n = 16, 75% CLN-S), staphylococcal scalded skin syndrome (n = 9, 56% CLN-S), eczema superinfection (n = 17, 53% CLN-S), bullous impetigo (n = 7, 40% CLN-S), and non-bullous impetigo (n = 7, 29%). Characteristics found to be associated with being CLN-S included abscess (OR 3.883, p = 0) and high white blood cell count (OR 2.482, p = 0.001). Characteristics associated with CLN-R included contact to person with abscess (OR 0.468, p = 0.035) and hypotension during infection (OR 0.312, p = 0.005). CONCLUSION: The use of institutional antibiograms to guide CLN susceptibility in CA SA infections may be limited by the type of infection, patient characteristics, and the likelihood of MSSA vs. MRSA infection. In our patients, having an abscess was associated with CLN-S. Empiric therapy of CA SA infections in children should not be driven solely by institutional antibiograms. DISCLOSURES: All Authors: No reported disclosures