The multifaceted lifestyle of enterococci: genetic diversity, ecology and risks for public health.

Enterococci are long-standing members of the gastrointestinal tract of humans and many animals and they are also ubiquitously distributed in natural environments. Classically as harmless bacteria, two main species (namely Enterococcus faecalis and Enterococcus faecium) have become a leading cause of human infections, especially in hospital settings, with the worldwide spread of multidrug-resistant isolates, especially vancomycin-resistant enterococci. In this review, it will be summarized what is known about genetic diversity and ecology of enterococci with a focus on E. faecalis and E. faecium from human and non-human habitats and related risks for public health.