Repurposing ebselen for decolonization of vancomycin-resistant enterococci (VRE)

PLoS One. 2018 Jun 28;13(6):e0199710. doi: 10.1371/journal.pone.0199710. eCollection 2018.

Abstract

Enterococci represent one of the microbial world's most challenging enigmas. Colonization of the gastrointestinal tract (GIT) of high-risk/immunocompromised patients by enterococci exhibiting resistance to vancomycin (VRE) can lead to life-threating infections, including bloodstream infections and endocarditis. Decolonization of VRE from the GIT of high-risk patients represents an alternative method to suppress the risk of the infection. It could be considered as a preventative measure to protect against VRE infections in high-risk individuals. Though multiple agents (ramoplanin and bacitracin) have been evaluated clinically, no drugs are currently approved for use in VRE decolonization of the GIT. The present study evaluates ebselen, a clinical molecule, for use as a decolonizing agent against VRE. When evaluated against a broad array of enterococcal isolates in vitro, ebselen was found to be as potent as linezolid (minimum inhibitory concentration against 90% of clinical isolates tested was 2 μg/ml). Though VRE has a remarkable ability to develop resistance to antibacterial agents, no resistance to ebselen emerged after a clinical isolate of vancomycin-resistant E. faecium was serially-passaged with ebselen for 14 days. Against VRE biofilm, a virulence factor that enables the bacteria to colonize the gut, ebselen demonstrated the ability to both inhibit biofilm formation and disrupt mature biofilm. Furthermore, in a murine VRE colonization reduction model, ebselen proved as effective as ramoplanin in reducing the bacterial shedding and burden of VRE present in the fecal content (by > 99.99%), cecum, and ileum of mice. Based on the promising results obtained, ebselen warrants further investigation as a novel decolonizing agent to quell VRE infection.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Azoles / pharmacology*
  • Biofilms / drug effects*
  • Biofilms / growth & development
  • Enterococcus faecium* / pathogenicity
  • Enterococcus faecium* / physiology
  • Female
  • Gram-Positive Bacterial Infections* / drug therapy
  • Gram-Positive Bacterial Infections* / microbiology
  • Isoindoles
  • Mice
  • Organoselenium Compounds / pharmacology*
  • Vancomycin Resistance / drug effects*
  • Virulence Factors / metabolism*

Substances

  • Azoles
  • Isoindoles
  • Organoselenium Compounds
  • Virulence Factors
  • ebselen