Activity of oritavancin tested against uncommonly isolated Gram-positive pathogens responsible for documented infections in hospitals worldwide

Abstract

To assess the oritavancin spectrum and activity against 2811 rarer species of coagulase-negative staphylococci (CoNS), streptococci and other Gram-positive species. A total of 2057 CoNS (14 species), 674 streptococci (7 groups) and 80 other Gram-positive species (3 genera) collected over a 5 year period as part of the SENTRY Program (2008-12) were included. Isolates were primarily identified by the participating laboratory and identification was confirmed by the reference monitoring laboratory (JMI Laboratories, North Liberty, IA, USA). Isolates were tested for susceptibility by broth microdilution following the CLSI M07-A9 and M100-S23 documents. Overall, oritavancin was active against all CoNS (MIC50/MIC90, 0.015/0.06 mg/L), with MIC50 values of ≤0.008-0.03 mg/L. Streptococci exhibited oritavancin MIC50 results of ≤0.008 mg/L, except for the Streptococcus bovis (0.03 mg/L), Streptococcus dysgalactiae (0.06 mg/L) and Streptococcus salivarius/vestibularis (0.06 mg/L) groups. Micrococcus spp., Listeria monocytogenes and Corynebacterium spp. had oritavancin MIC50 results of ≤0.008 mg/L. This study expands the oritavancin in vitro data against several species of Gram-positive organisms.