Incidence and antimicrobial resistance trends in bloodstream infections caused by ESKAPE and Escherichia coli at a large teaching hospital in Rome, a 9-year analysis (2007-2015)

The proportion of antimicrobial resistance (AMR) among the ESKAPE and Escherichia coli (ESKAPEEc) pathogens causing bloodstream infection (BSI) increased worldwide. We described longitudinal trends in ESKAPEEc BSI and AMR over 9 years (2007-2015) at a large teaching hospital in Italy. Of 9720 unique BSI episodes, 6002 (61.7%) were caused by ESKAPEEc pathogens. The majority of these episodes (4374; 72.9%) were hospital-onset infections. The most frequent pathogen was E. coli (32.8%), followed by Staphylococcus aureus (20.6%), Klebsiella pneumoniae (16.1%), and Pseudomonas aeruginosa (11.6%). There was a significant increase of hospital-onset K. pneumoniae (from 2.3 to 5.0 per 10,000 patient-days; P = 0.001) and community-onset E. coli (from 3.3 to 9. 1 per 10,000 emergency admissions; P = 0.04) BSIs. Among hospital-onset BSIs, increases of extended-spectrum beta-lactamase (ESBL)-producing E. coli (from 25.4 to 35.2%, P = 0.006), carbapenemase-producing K. pneumoniae (from 4.2 to 51.6%, P < 0.001), and methicillin-resistant S. aureus (from 33.9 to 44.4%, P < 0.001) BSIs were observed between the 2007-2009 and 2010-2012 study periods. In contrast, a decrease of BSIs caused by P. aeruginosa resistant to ceftazidime (from 45.5 to 28.2%, P < 0.001), ciprofloxacin (from 46 to 36.3%, P = 0.05), and meropenem (from 55 to 39.9%, P = 0.03) was observed through all 9 years of the study period. Among community-onset BSIs, increases of BSIs caused by ESBL-producing E. coli (from 28.6 to 42.2%, P = 0.002) and carbapenemase-producing K. pneumoniae (from 0 to 17.6%) were observed between the 2007-2009 and 2010-2012 study periods. Our findings show increased rates of BSI and relative AMR for specific pathogen-health care setting combinations, and call for continued active surveillance and infection control policies.