Skip to main content
Article thumbnail
Location of Repository

Enterococcus faecalis Endocarditis Severity in Rabbits Is Reduced by IgG Fabs Interfering with Aggregation Substance

By Patrick M. Schlievert, Olivia N. Chuang-smith, Marnie L. Peterson, Laura C. C. Cook and Gary M. Dunny

Abstract

Background: Enterococcus faecalis is a significant cause of infective endocarditis, an infection of the heart endothelium leading to vegetation formation (microbes, fibrin, platelets, and host cells attached to underlying endothelial tissue). Our previous research determined that enterococcal aggregation substance (AS) is an important virulence factor in causation of endocarditis, although endocarditis may occur in the absence of AS production. Production of AS by E. faecalis causes the organism to form aggregates through AS binding to enterococcal binding substance. In this study, we assessed the ability of IgGs and IgG Fabs against AS to provide protection against AS + E. faecalis endocarditis. Methodology/Principal Findings: When challenged with AS + E. faecalis, 10 rabbits actively immunized against AS + E. faecalis developed more significant vegetations than 9 animals immunized against AS 2 E. faecalis, and 9/10 succumbed compared to 2/9 (p,0.005), suggesting enhanced aggregation by IgG contributes significantly to disease. IgG antibodies against AS also enhanced enterococcal aggregation as tested in vitro. In contrast, Fab fragments of IgG from rabbits immunized against purified AS, when passively administered to rabbits (6/group) immediately before challenge with AS + E. faecalis, reduced total vegetation (endocarditis lesion) microbial counts (7.9610 6 versus 2.0610 5, p = 0.02) and size (40 mg versus 10, p = 0.05). In vitro, the Fabs prevented enterococcal aggregation. Conclusions/Significance: The data confirm the role of AS in infective endocarditis formation and suggest that use of Fab

Year: 2010
OAI identifier: oai:CiteSeerX.psu:10.1.1.352.621
Provided by: CiteSeerX
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://citeseerx.ist.psu.edu/v... (external link)
  • ftp://ftp.ncbi.nlm.nih.gov/pub... (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.