Enterococcus faecium: from evolutionary insights to practical interventions

Enterococcus faecium has rapidly become a successful nosocomial pathogen. Early in its evolution E. faecium already possessed traits such as high tenacity, resistance to antibiotics and environmental stresses which made it capable to survive in a hospital environment. In the antibiotic era, E. faecium acquired resistance and virulence genes and soon the success of E. faecium became clear in the hospitals. In European hospitals, infections caused by E. faecium started to rise around 2000, followed by an increase of vancomycin resistant E. faecium (VRE). In this thesis we aimed to gain insight in the evolution and epidemiology of E. faecium. From these insights, this thesis proceeds to interventions that have value for patient care. The rapid emergence of hospital lineages imposes challenges for controlling, detecting and typing of VRE. To overcome these challenges, antibiotic stewardship strategies and diagnostic innovations using molecular techniques are required. This thesis describes such interventions, including model-based antibiotic prescription guidance, tailor made diagnostic tools for (vancomycin resistant) E. faecium, targeted VRE infection prevention measures and highly discriminating typing methods in VRE outbreak investigations. Finally, since the evolution in E. faecium will never stop, it will be a challenge to withstand the spread of VRE in the upcoming years. Therefore, innovations in the fields of diagnostics, treatment, and eradication is necessary to tackle the ongoing success of E. faecium.