scholarly journals Enterococcus faecalis pCF10-encoded surface proteins PrgA, PrgB (aggregation substance) and PrgC contribute to plasmid transfer, biofilm formation and virulence

2014 ◽  
Vol 95 (4) ◽  
pp. 660-677 ◽  
Author(s):  
Minny Bhatty ◽  
Melissa R. Cruz ◽  
Kristi L. Frank ◽  
Jenny A. Laverde Gomez ◽  
Fernando Andrade ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Biofilm Formation ◽  
Plasmid Transfer ◽  
Surface Proteins ◽  
Aggregation Substance

scholarly journals Planktonic Interference and Biofilm Alliance between Aggregation Substance and Endocarditis- and Biofilm-Associated Pili inEnterococcus faecalis

2018 ◽  
Vol 200 (24) ◽  
Author(s):  
Irina Afonina ◽  
Xin Ni Lim ◽  
Rosalind Tan ◽  
Kimberly A. Kline
Keyword(s):  
Enterococcus Faecalis ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Opportunistic Pathogen ◽  
Plasmid Transfer ◽  
Conjugative Plasmid ◽  
Content Type ◽  
Regulatory Pathways ◽  
Aggregation Substance ◽  
Biofilm Development

ABSTRACTLike many bacteria,Enterococcus faecalisencodes a number of adhesins involved in colonization or infection of different niches. Two well-studiedE. faecalisadhesins, aggregation substance (AS) and endocarditis- and biofilm-associated pili (Ebp), both contribute to biofilm formation on abiotic surfaces and in endocarditis, suggesting that they may be expressed at the same time. Because different regulatory pathways have been reported for AS and Ebp, here, we examined if they are coexpressed on the same cells and what is the functional impact of coexpression on individual cells and within a population. We found that while Ebp are only expressed on a subset of cells, when Ebp and AS are expressed on the same cells, pili interfere with AS-mediated clumping and impede AS-mediated conjugative plasmid transfer during planktonic growth. However, when the population density increases, horizontal gene transfer rates normalize and are no longer affected by pilus expression. Instead, at higher cell densities during biofilm formation, Ebp and AS differentially contribute to biofilm development and structure, synergizing to promote maximal biofilm formation.IMPORTANCEMost bacteria express multiple adhesins that contribute to surface attachment and colonization. However, the network and relationships between the various adhesins of a single bacterial species are less well understood. Here, we examined two well-characterized adhesins inEnterococcus faecalis, aggregation substance and endocarditis- and biofilm-associated pili, and found that they exhibit distinct functional contributions depending on the growth stage of the bacterial community. Pili interfere with aggregation substance-mediated clumping and plasmid transfer under planktonic conditions, whereas the two adhesins structurally complement one another during biofilm development. This study advances our understanding of howE. faecalis, a ubiquitous member of the human gut microbiome and an opportunistic pathogen, uses multiple surface structures to evolve and thrive.

scholarly journals Adhesion to Bile Drain Materials and Physicochemical Surface Properties of Enterococcus faecalis Strains Grown in the Presence of Bile

2002 ◽  
Vol 68 (8) ◽  
pp. 3855-3858 ◽  
Author(s):  
Karola Waar ◽  
Henny C. van der Mei ◽  
Hermie J. M. Harmsen ◽  
John E. Degener ◽  
Henk J. Busscher
Keyword(s):  
Surface Properties ◽  
Enterococcus Faecalis ◽  
Photoelectron Spectroscopy ◽  
Surface Protein ◽  
Lower Surface ◽  
Contact Angles ◽  
Surface Proteins ◽  
Water Contact ◽  
Zeta Potentials ◽  
Aggregation Substance

ABSTRACT The aim of this study is to determine whether growth in the presence of bile influences the surface properties and adhesion to hydrophobic bile drain materials of Enterococcus faecalis strains expressing aggregation substance (Agg) or enterococcal surface protein (Esp), two surface proteins that are associated with infections. After growth in the presence of bile, the strains were generally more hydrophobic by water contact angles and the zeta potentials were more negative than when the strains were grown in the absence of bile. Nitrogen was found in lower surface concentrations upon growth in the presence of bile, whereas higher surface concentrations of oxygen were measured by X-ray photoelectron spectroscopy. Moreover, an up to twofold-higher number of bacteria adhered after growth in bile for E. faecalis not expressing Agg or Esp and E. faecalis with Esp on its surface. E. faecalis expressing Agg did not adhere in higher numbers after growth in bile, possibly because they mainly adhere through positive cooperativity and less through direct interactions with a substratum surface. Since adhesion of bacteria is the first step in biomaterial-centered infection, it can be concluded that growth in bile increases the virulence of E. faecalis.

scholarly journals Role of the Enterococcus faecalis GelE Protease in Determination of Cellular Chain Length, Supernatant Pheromone Levels, and Degradation of Fibrin and Misfolded Surface Proteins

2003 ◽  
Vol 185 (12) ◽  
pp. 3613-3623 ◽  
Author(s):  
Christopher M. Waters ◽  
Michelle H. Antiporta ◽  
Barbara E. Murray ◽  
Gary M. Dunny
Keyword(s):  
Chain Length ◽  
Enterococcus Faecalis ◽  
Epidemiological Data ◽  
Surface Proteins ◽  
Mutant Proteins ◽  
Model Studies ◽  
Aggregation Substance ◽  
Peptide Pheromone

ABSTRACT Gelatinase (GelE), a secreted Zn-metalloprotease of Enterococcus faecalis, has been implicated as a virulence factor by both epidemiological data and animal model studies. Expression of gelE is induced at a high cell density by the fsr quorum-sensing system. In the present study, GelE was shown to be responsible for the instability of a number of Asc10 (aggregation substance) mutant proteins, implying that GelE functions to clear the bacterial cell surface of misfolded proteins. Disruption of GelE production led to increased cell chain length of E. faecalis, from a typical diplococcus morphology to chains of 5 to 10 cells. This function of GelE was also exhibited when the protein was expressed in Streptococcus pyogenes. GelE-expressing E. faecalis strains were more autolytic, suggesting that GelE affects chain length through activation of an autolysin. GelE was also essential for degradation of polymerized fibrin. GelE expression reduced the titer of cCF10, the peptide pheromone that induces conjugation of pCF10, and pCF10 had increased conjugation into non-GelE-expressing strains. These new functions attributed to GelE suggest that it acts to increase the dissemination of E. faecalis in high-density environments.

scholarly journals Acceleration of Enterococcus faecalis Biofilm Formation by Aggregation Substance Expression in an Ex Vivo Model of Cardiac Valve Colonization

PLoS ONE ◽  
2010 ◽  
Vol 5 (12) ◽  
pp. e15798 ◽  
Author(s):  
Olivia N. Chuang-Smith ◽  
Carol L. Wells ◽  
Michelle J. Henry-Stanley ◽  
Gary M. Dunny
Keyword(s):  
Enterococcus Faecalis ◽  
Biofilm Formation ◽  
Ex Vivo ◽  
Cardiac Valve ◽  
Ex Vivo Model ◽  
Aggregation Substance

Bacteriocin plasmid pMB1 of Enterococcus faecalis: identification of the cell aggregation substance after induction by sex pheromone

1994 ◽  
Vol 40 (6) ◽  
pp. 500-503 ◽  
Author(s):  
R. Quirantes ◽  
I. Martín ◽  
E. Valdivia ◽  
A. Gálvez ◽  
M. Martínez-Bueno ◽  
...  
Keyword(s):  
Surface Layer ◽  
Electron Microscope ◽  
Sex Pheromone ◽  
Scanning Electron Microscope ◽  
Enterococcus Faecalis ◽  
Cell Aggregation ◽  
Surface Proteins ◽  
Aggregation Substance ◽  
Culture Supernatants ◽  
Scanning Electron

Strains of Enterococcus faecalis carrying the bacteriocinogenic plasmids pMB1 or pMB 1.1 exhibit a clumping response to culture supernatants of different enterococcal strains. Antibodies raised against cells induced by a homologous pheromone recognize two surface proteins of 152 and 72.5 kDa (the second one is possibly the degradation product of the first), respectively. These antigens are very similar to those found in induced cells of E. faecalis OGIRF(pAM211) as shown by the cross-reaction of the immune sera obtained in this work. We propose that the 152-kDa protein corresponds to the aggregation substance coded by plasmids pMB1 and pMB1.1. Moreover, antibodies raised against induced cells are able to block the pheromone-induced clumping response. When the cells induced to form aggregates by pheromones were examined under a scanning electron microscope they showed a surface layer of hairlike structures.Key words: pMB1 plasmid, sex pheromone, aggregation substance, Enterococcus faecalis.

scholarly journals Multiple Functional Domains of Enterococcus faecalis Aggregation Substance Asc10 Contribute to Endocarditis Virulence

2008 ◽  
Vol 77 (1) ◽  
pp. 539-548 ◽  
Author(s):  
Olivia N. Chuang ◽  
Patrick M. Schlievert ◽  
Carol L. Wells ◽  
Dawn A. Manias ◽  
Timothy J. Tripp ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Bacterial Load ◽  
Rabbit Model ◽  
Surface Proteins ◽  
Functional Domains ◽  
Mammalian Host ◽  
Bacterial Cells ◽  
Wild Type ◽  
Aggregation Substance

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.

scholarly journals Characterization of the Pheromone Response of the Enterococcus faecalis Conjugative Plasmid pCF10: Complete Sequence and Comparative Analysis of the Transcriptional and Phenotypic Responses of pCF10-Containing Cells to Pheromone Induction

2005 ◽  
Vol 187 (3) ◽  
pp. 1044-1054 ◽  
Author(s):  
Helmut Hirt ◽  
Dawn A. Manias ◽  
Edward M. Bryan ◽  
Joanna R. Klein ◽  
Jesper K. Marklund ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Complete Sequence ◽  
Plasmid Transfer ◽  
Open Reading Frames ◽  
Conjugative Plasmid ◽  
Transfer Rates ◽  
Aggregation Substance ◽  
Clear Peak ◽  
Plasmid Genes

ABSTRACT The sex pheromone plasmids in Enterococcus faecalis are one of the most efficient conjugative plasmid transfer systems known in bacteria. Plasmid transfer rates can reach or exceed 10−1 transconjugants per donor in vivo and under laboratory conditions. We report the completion of the DNA sequence of plasmid pCF10 and the analysis of the transcription profile of plasmid genes, relative to conjugative transfer ability following pheromone induction. These experiments employed a mini-microarray containing all 57 open reading frames of pCF10 and a set of selected chromosomal genes. A clear peak of transcription activity was observed 30 to 60 min after pheromone addition, with transcription subsiding 2 h after pheromone induction. The transcript activity correlated with the ability of donor cells to transfer pCF10 to recipient cells. Remarkably, aggregation substance (Asc10, encoded by the prgB gene) was present on the cell surface for a long period of time after pheromone-induced transcription of prgB and plasmid transfer ability had ceased. This observation could have relevance for the virulence of E. faecalis.

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