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Opsonophagocytic Killing Assay to Assess Immunological Responses Against Bacterial Pathogens
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Opsonophagocytic Killing Assay to Assess Immunological Responses Against Bacterial Pathogens

Published on: April 5, 2019

Rationale for the development of immunotherapy regimens against enterococcal infections

Christian Theilacker1, Wolfgang A Krueger, Andrea Kropec

  • 1Infectious Diseases, Department of Medicine, University Hospital Freiburg, Germany.

Vaccine
|December 4, 2004
PubMed

Insights

Enterococci cause frequent bloodstream infections, and rising antimicrobial resistance necessitates new treatments. Capsular polysaccharide of Enterococcus faecalis shows promise as a vaccine candidate against these difficult-to-treat infections.

Area of Science:

  • Microbiology
  • Immunology
  • Vaccinology

Background:

  • Enterococci are a leading cause of hospital-acquired bloodstream infections.
  • Increasing antimicrobial resistance limits treatment options for enterococcal infections.
  • Novel therapeutic strategies, including vaccines, are urgently needed.

Purpose of the Study:

  • To evaluate the potential of Enterococcus faecalis capsular polysaccharide as a vaccine candidate.
  • To assess the immunogenicity and protective efficacy of antibodies against the capsular polysaccharide.

Main Methods:

  • Immunization of mice with purified capsular polysaccharide.
  • Assessment of antibody opsonic activity.
  • Evaluation of protection against bacteremia via active and passive immunization.

Main Results:

  • Antibodies against the capsular polysaccharide were highly opsonic.
  • Active and passive immunization with anti-capsular polysaccharide antibodies protected mice against E. faecalis bacteremia.
  • E. faecalis exhibits a limited number of capsular serotypes.

Conclusions:

  • The capsular polysaccharide of Enterococcus faecalis is a promising target for vaccine development.
  • A conjugate vaccine based on the capsular polysaccharide could be an effective strategy against E. faecalis infections.
  • Further research into E. faecalis vaccine development is warranted.

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