1191. Prevalence and Microbiology of Carbapenem Resistance Among Six Gram-Negative Pathogens in Bloodstream Infections in US Hospitals, 2010–2015

Abstract

Abstract Background Carbapenem resistance (CR) is a growing threat in hospitals in the United States and worldwide. We evaluated the prevalence and geographic distribution of CR among six most common Gram-negative (GN) bloodstream infection (BSI) pathogens in US hospitals. Methods We analyzed microbiology data in a cohort of adults (≥18 years) hospitalized in 181 US hospitals contributing microbiology data to the Premier Healthcare Database (October 2010–September 2015) with blood cultures positive for six most common GN pathogens (S. maltophilia assumed 100% CR). We report CR prevalence by pathogen, hospital ward (ICU vs. floor), and census region. Results Of the 43,095 GN BSIs included, 1,513 (3.5%) were caused by the six most common CR pathogens (Figure 1). CR was more frequently isolated from patients with an ICU stay (4.7%) vs. those without (2.7%). Nearly 75% (n = 1,100) of CR occurred in nonfermenters (S. maltophilia, P. aeruginosa, and A. baumannii). Among individual organisms, the prevalence of CR—outside of S. maltophilia—was highest among A. baumannii, 35.1%, and lowest among E. coli, 0.2% (Figure 2). Geographically, CR prevalence ranged from highest in the Mountain region (7.1%) to lowest in the West North Central (2.3%) (Figure 3). The maximum CR prevalence occurred in A. baumannii from the East North Central (55.7%), and the minimum in E. coli from the West North Central (0.05%) regions. Conclusion Among six most frequently isolated pathogens in BSI, the overall CR prevalence is 3.5%. The wide variations in prevalence based on organism, location in the hospital, and geography emphasize the clinical importance of knowing local pathogen and resistance patterns in order to optimize empiric treatment. Disclosures A. F. Shorr, Astellas: Consultant and Speaker’s Bureau, Consulting fee, Research support and Speaker honorarium. Cidara: Consultant, Consulting fee. Merck & Co.: Consultant and Speaker’s Bureau, Consulting fee, Research support and Speaker honorarium. T. P. Lodise Jr., Motif BioSciences: Board Member, Consulting fee.