Distribution of main Gram-positive pathogens causing bloodstream infections in United States and European hospitals during the SENTRY Antimicrobial Surveillance Program (2010-2016): concomitant analysis of oritavancin in vitro activity.

This study updates the distribution and trends of Gram-positive organisms causing bloodstream infections (BSIs) in the United States (US) and Europe during 2010-2016. In vitro activities of oritavancin and comparators were also evaluated. Staphylococcus aureus, Enterococcus spp., and coagulase-negative staphylococci (CoNS) were the most common organisms in both regions. The proportion of methicillin-resistant S. aureus (MRSA) among all isolates declined (from 11.5% to 9.9%) in the US, a trend also noted for methicillin resistance rates within S. aureus (from 45.7% to 41.9%). MRSA rates (4.1% to 4.2%) in Europe remained stable during 2013-2016. Enterococcus faecalis (7.0-5.2%) and E. faecium (5.1-3.0%) rates declined in the US while remaining stable in Europe (4.5-5.7% and 3.3-4.7%, respectively). Rates for CoNS increased in the US; no temporal trends were noted in Europe. Oritavancin (MIC50/90, 0.03/0.06 µg/mL) inhibited 99.7-99.8% of S. aureus from both regions at ≤0.12 µg/mL and inhibited 96.8-97.9% of E. faecalis and 99.1-99.9% of E. faecium at this concentration. Oritavancin inhibited 99.7% of streptococci at the susceptible breakpoint. This study updates the distribution of pathogens causing BSI in the US and Europe. The in vitro activity for oritavancin against BSI pathogens supports its further development for bacteraemia.