Journal article
Multiple Functional Domains of Enterococcus faecalis Aggregation Substance Asc10 Contribute to Endocarditis Virulence
Infection and immunity, Vol.77(1), pp.539-548
01/2009
DOI: 10.1128/IAI.01034-08
PMCID: PMC2612263
PMID: 18955479
Abstract
Aggregation substance proteins encoded by sex pheromone plasmids increase the virulence of
Enterococcus faecalis
in experimental pathogenesis models, including infectious endocarditis models. These large surface proteins may contain multiple functional domains involved in various interactions with other bacterial cells and with the mammalian host. Aggregation substance Asc10, encoded by plasmid pCF10, is induced during growth in the mammalian bloodstream, and pCF10 carriage gives
E. faecalis
a significant selective advantage in this environment. We employed a rabbit model to investigate the role of various functional domains of Asc10 in endocarditis. The data suggested that the bacterial load of the infected tissue was the best indicator of virulence. Isogenic strains carrying either no plasmid, wild-type pCF10, a pCF10 derivative with an in-frame deletion of the
prgB
gene encoding Asc10, or pCF10 derivatives expressing other alleles of
prgB
were examined in this model. Previously identified aggregation domains contributed to the virulence associated with the wild-type protein, and a strain expressing an Asc10 derivative in which glycine residues in two RGD motifs were changed to alanine residues showed the greatest reduction in virulence. Remarkably, this strain and the strain carrying the pCF10 derivative with the in-frame deletion of
prgB
were both significantly less virulent than an isogenic plasmid-free strain. The data demonstrate that multiple functional domains are important in Asc10-mediated interactions with the host during the course of experimental endocarditis and that in the absence of a functional
prgB
gene, pCF10 carriage is actually disadvantageous in vivo.
Details
- Title: Subtitle
- Multiple Functional Domains of Enterococcus faecalis Aggregation Substance Asc10 Contribute to Endocarditis Virulence
- Creators
- Olivia N Chuang - Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455Patrick M Schlievert - Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455Carol L Wells - Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455Dawn A Manias - Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455Timothy J Tripp - Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455Gary M Dunny - Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455
- Resource Type
- Journal article
- Publication Details
- Infection and immunity, Vol.77(1), pp.539-548
- DOI
- 10.1128/IAI.01034-08
- PMID
- 18955479
- PMCID
- PMC2612263
- NLM abbreviation
- Infect Immun
- ISSN
- 0019-9567
- eISSN
- 1098-5522
- Publisher
- American Society for Microbiology (ASM)
- Language
- English
- Date published
- 01/2009
- Academic Unit
- Microbiology and Immunology; Internal Medicine
- Record Identifier
- 9984001147402771
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