Enterococcal Physiology and Antimicrobial Resistance: The Streetlight Just Got a Little Brighter

Enterococcus faecalis differs from many other common human pathogens in its physiology and in its susceptibility to antimicrobial agents. Multiresistant E. faecalis strains owe their phenotypes to a combination of intrinsic and acquired antimicrobial resistance determinants. Acquired resistance is due to E. faecalis frequenting multicultural environments, its capacity to mate with different species, and the nullification of its own defense mechanisms in some lineages. Intrinsic resistance is a complex phenomenon that is intimately tied to the physiology of the species. In their recent study in mBio, Gilmore and colleagues (M. S. Gilmore, R. Salamzade, E. Selleck, N. Bryan, et al., mBio 11:e02962-20, 2020, https://doi.org/10.1128/mBio.02962-20) use functional genomics to explore the genetic underpinnings of E. faecalis physiology and antimicrobial resistance. While they do not come up with many definitive answers, their work points the way toward new and fruitful areas of investigation.