Advances and Prospects in Vaccine Development against Enterococci

Abstract

Enterococci are the second most common Gram-positive pathogen responsible for nosocomial infections. Due to the limited number of new antibiotics that reach the medical practice and the resistance of enterococci to the current antibiotic options, passive and active immunotherapies have emerged as a potential prevention and/or treatment strategy against this opportunistic pathogen. In this review, we explore the pathogenicity of these bacteria and their interaction with the host immune response. We provide an overview of the capsular polysaccharides and surface-associated proteins that have been described as potential antigens in anti-enterococcal vaccine formulations. In addition, we describe the current status in vaccine development against enterococci and address the importance and the current advances toward the development of well-defined vaccines with broad coverage against enterococci.

Keywords: Enterococcus faecalis; Enterococcus faecium; VRE; antibodies; enterococci; glycoconjugate vaccine; polysaccharide; vaccine; vancomycin-resistant enterococci.

Figure 1

Chemical structure of (a) the 1, 3-polyglycerolphosphate backbone of LTA isolated from E. faecalis 12030, substituted at the position C-2, with R1 = d-Alanine, R2 = kojibiose, or R3 = alanylated kojibiose [73], and (b) DHG isolated from E. faecalis Type 2, unsubstituted (R4) or acetylated (R5) [83].