728. Activity of Eravacycline Against Contemporary Gram-Negative Clinical Isolates From New York City Hospitals

Abstract

BackgroundAntibiotic-resistant Gram-negative bacteria, including KPC-producing Enterobacteriaceae and carbapenem-resistant A. baumannii, have been problematic hospital pathogens in NYC and other areas. Eravacycline (ERV), a fluorocycline antibiotic released in the USA in 2018, has demonstrated in vitro activity against many of these strains. We tested the activity of ERV against a recent collection of clinical isolates from NYC hospitals.MethodsFor a 3-month period in 2017, all unique patient isolates of E. coli, K. pneumoniae, Enterobacter spp., and A. baumannii were collected from 7 hospitals in Brooklyn, NY. MICs were performed by broth microdilution for ERV and Tigecycline (TGC) and agar dilution for other antibiotics according to CLSI methodology. Cephalosporin-resistant isolates were screened by PCR for common carbapenemases.ResultsThe susceptibility results for tetracycline and ERV are listed in the Table. Overall, 95% of the Enterobacteriaceae were inhibited by ≤ 0.5 μg/mL of ERV, the FDA-suggested breakpoint. Of 1,876 isolates of E. coli, 4 possessed KPC. ERV MICs for these 4 isolates were 0.125–0.25 μg/mL. Of 518 isolates of K. pneumoniae, 20 possessed KPC. The ERV MIC50 and MIC90 for these isolates were 1 and 1 μg/mL, respectively. Of 172 isolates of Enterobacter spp., 3 possessed KPC. ERV MICs for these 3 isolates were 0.5–1 μg/mL. Of 45 isolates of A. baumannii, 11 isolates possessed a carbapenemase (OXA23 in 8, OXA24 in 2, and KPC in 1). The ERV MIC50 and MIC90 for these isolates were 1 and 2 μg/mL, respectively. Overall, ERV MICs were two-fold lower than TGC MICs for A. baumannii.ConclusionERV possesses significant in vitro activity against contemporary clinical isolates of Enterobacteriaceae and A. baumannii from NYC, including many carbapenemase producing strains. Disclosures All authors: No reported disclosures.