Role of mprF1 and mprF2 in the Pathogenicity of Enterococcus faecalis

ABSTRACT Commensal and generally harmless in healthy individuals, Enterococcus faecalis causes opportunistic infections in immunocompromised patients. Plasmid-cured E. faecalis strain VE14089, derived from sequenced reference strain V583, is widely used for functional studies due to its improved genetic amenability. Although strain VE14089 has no major DNA rearrangements, with the exception of an ∼20-kb integrated region of pTEF1 plasmid, the strain presented significant growth differences from the V583 reference strain of our collection (renamed VE14002). In the present study, genome sequencing of strain VE14089 identified additional point mutations. Excision of the integrated pTEF1 plasmid region and sequential restoration of wild-type alleles showing nonsilent mutations were performed to obtain the VE18379 reference-derivative strain. Recovery of the growth ability of the restored VE18379 strain at a level similar to that seen with the reference strain points to GreA and Spx as bacterial fitness determinants. Virulence potential in Galleria mellonella and intestinal colonization in mouse demonstrated host adaptation of the VE18379 strain equivalent to VE14002 host adaptation. We further demonstrated that deletion of the 16.8-kb variable region of the epa locus recapitulates the key role of Epa decoration in host adaptation, providing a genetic system to study the role of specific epa-variable regions in host adaptation independently of other genetic variations. IMPORTANCE E. faecalis strain VE14089 was derived from V583 cured of its plasmids. Although VE14089 had no major DNA rearrangements, it presented significant growth and host adaptation differences from the reference strain V583 of our collection. To construct a strain with better fitness, we sequenced the genome of VE14089, identified single nucleotide polymorphisms (SNPs), and repaired the genes that could account for these changes. Using this reference-derivative strain, we provide a novel genetic system to understand the role of the variable region of epa in the enterococcal lifestyle.

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Role of Polymorphonuclear Neutrophils in the Clearance of Enterococcus faecalis Derived from Saliva and Infected Root Canals

Journal of Endodontics ◽

10.1016/j.joen.2010.11.033 ◽

2011 ◽

Vol 37 (3) ◽

pp. 346-352 ◽

Cited By ~ 6

Author(s):

Zeyun Ma ◽

Yixiang Wang ◽

Xiaofei Zhu ◽

Chengfei Zhang ◽

Shenglin Li ◽

...

Keyword(s):

Enterococcus Faecalis ◽

Polymorphonuclear Neutrophils ◽

Root Canals ◽

Infected Root

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Uncommitted role of enterococcal surface protein, Esp, and origin of isolates on biofilm production by Enterococcus faecalis isolated from bovine mastitis

Journal of Microbiology Immunology and Infection ◽

10.1016/j.jmii.2012.02.002 ◽

2013 ◽

Vol 46 (2) ◽

pp. 80-84 ◽

Cited By ~ 16

Author(s):

Mohamed Elhadidy ◽

Asmaa Elsayyad

Keyword(s):

Enterococcus Faecalis ◽

Bovine Mastitis ◽

Surface Protein ◽

Biofilm Production

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Enterococcus faecalis translocation in mice with severe burn injury: a pathogenic role of CCL2 and alternatively activated macrophages (M2aMϕ and M2cMϕ)

Journal of Leukocyte Biology ◽

10.1189/jlb.0409235 ◽

2009 ◽

Vol 86 (4) ◽

pp. 999-1005 ◽

Cited By ~ 24

Author(s):

Kenji Shigematsu ◽

Akira Asai ◽

Makiko Kobayashi ◽

David N. Herndon ◽

Fujio Suzuki

Keyword(s):

Enterococcus Faecalis ◽

Burn Injury ◽

Activated Macrophages ◽

Severe Burn ◽

Pathogenic Role ◽

Alternatively Activated Macrophages ◽

Severe Burn Injury ◽

Alternatively Activated

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Evidence of the proinflammatory role of Enterococcus faecalis in polymicrobial peritonitis in rats.

Infection and Immunity ◽

10.1128/iai.65.1.144-149.1997 ◽

1997 ◽

Vol 65 (1) ◽

pp. 144-149 ◽

Cited By ~ 36

Author(s):

P Montravers ◽

J Mohler ◽

L Saint Julien ◽

C Carbon

Keyword(s):

Enterococcus Faecalis ◽

Proinflammatory Role

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Development of fluoroquinolone resistance in Enterococcus faecalis and role of mutations in the DNA gyrase gyrA gene.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.40.11.2558 ◽

1996 ◽

Vol 40 (11) ◽

pp. 2558-2561 ◽

Cited By ~ 30

Author(s):

J Tankovic ◽

F Mahjoubi ◽

P Courvalin ◽

J Duval ◽

R Leclerco

Keyword(s):

Enterococcus Faecalis ◽

Resistant Isolate ◽

Fluoroquinolone Resistance ◽

Gyra Gene ◽

Single Clone ◽

Total Dna ◽

Resistant Strains ◽

French Hospital ◽

High Level

We have analyzed the development of fluoroquinolone resistance between 1986 and 1993 among clinical isolates of Enterococcus faecalis from a French hospital. One hundred randomly selected isolates per year were screened for resistance to ciprofloxacin (MIC > 2 micrograms/ml) and for high-level resistance to gentamicin (MIC > 1,000 micrograms/ml). The percentages of ciprofloxacin-resistant strains for these years were as follows: 1986, 0; 1987, 1; 1988 to 1989, 2; 1990, 6; 1991, 16; 1992, 24; and 1993, 14. Eighty-three percent of the ciprofloxacin-resistant isolates were coresistant to high levels of gentamicin. Forty-eight high-level gentamicin-resistant E. faecalis strains, which were resistant (24 strains) or susceptible (24 strains) to ciprofloxacin, were examined by pulsed-field gel electrophoresis (PFGE) of SmaI-digested total DNA. Numerous PFGE types were observed among the ciprofloxacin-susceptible isolates, whereas one type was largely predominant among the ciprofloxacin-resistant strains, which suggests that the increase in fluoroquinolone resistance was due to the spread of a single clone. A 241-bp fragment of gyrA, corresponding to the quinolone resistance-determining region, was amplified and sequenced for seven ciprofloxacin-resistant isolates. Six strains had high levels of resistance (MICs, 32 to 64 micrograms/ml) and had a mutation at position 83 (Escherichia coli coordinates) from Ser to Arg (three strains) or to Ile (two strains) or at position 87 from Glu to Gly (one strain), whereas the low-level-resistant isolate (MIC, 8 micrograms/ml) had no mutations.

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Mechanism for Sortase Localization and the Role of Sortase Localization in Efficient Pilus Assembly in Enterococcus faecalis

Journal of Bacteriology ◽

10.1128/jb.01837-08 ◽

2009 ◽

Vol 191 (10) ◽

pp. 3237-3247 ◽

Cited By ~ 61

Author(s):

Kimberly A. Kline ◽

Andrew L. Kau ◽

Swaine L. Chen ◽

Adeline Lim ◽

Jerome S. Pinkner ◽

...

Keyword(s):

Enterococcus Faecalis ◽

Virulence Factors ◽

Transmembrane Helix ◽

Spatial Relationship ◽

Sortase A ◽

Aggregation Substance ◽

Retention Signal ◽

Positively Charged ◽

Pilus Assembly

ABSTRACT Pathogenic streptococci and enterococci primarily rely on the conserved secretory (Sec) pathway for the translocation and secretion of virulence factors out of the cell. Since many secreted virulence factors in gram-positive organisms are subsequently attached to the bacterial cell surface via sortase enzymes, we sought to investigate the spatial relationship between secretion and cell wall attachment in Enterococcus faecalis. We discovered that sortase A (SrtA) and sortase C (SrtC) are colocalized with SecA at single foci in the enterococcus. The SrtA-processed substrate aggregation substance accumulated in single foci when SrtA was deleted, implying a single site of secretion for these proteins. Furthermore, in the absence of the pilus-polymerizing SrtC, pilin subunits also accumulate in single foci. Proteins that localized to single foci in E. faecalis were found to share a positively charged domain flanking a transmembrane helix. Mutation or deletion of this domain in SrtC abolished both its retention at single foci and its function in efficient pilus assembly. We conclude that this positively charged domain can act as a localization retention signal for the focal compartmentalization of membrane proteins.

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SlyA Is a Transcriptional Regulator Involved in the Virulence of Enterococcus faecalis

Infection and Immunity ◽

10.1128/iai.01132-10 ◽

2011 ◽

Vol 79 (7) ◽

pp. 2638-2645 ◽

Cited By ~ 39

Author(s):

Charlotte Michaux ◽

Maurizio Sanguinetti ◽

Fany Reffuveille ◽

Yanick Auffray ◽

Brunella Posteraro ◽

...

Keyword(s):

Enterococcus Faecalis ◽

Galleria Mellonella ◽

Peritoneal Macrophages ◽

Bacterial Virulence ◽

Transcriptional Analysis ◽

Infection Model ◽

Wild Type ◽

Content Type ◽

Wild Type Parent

ABSTRACTPhylogenetic analysis of the crystal structure of theEnterococcus faecalisSlyA (EF_3002) transcriptional factor places it between the SlyA and MarR regulator subfamilies. Proteins of these families are often involved in the regulation of genes important for bacterial virulence and stress response. To gather evidence for the role of this putative regulator inE. faecalisbiology, we dissected the genetic organization of theslyA-EF_3001 locus and constructed aslyAdeletion mutant as well as complemented strains. Interestingly, compared to the wild-type parent, the ΔslyAmutant is more virulent in an insect infection model (Galleria mellonella), exhibits increased persistence in mouse kidneys and liver, and survives better inside peritoneal macrophages. In order to identify a possible SlyA regulon, global microarray transcriptional analysis was performed. This study revealed that theslyA-EF_3001 locus appears to be autoregulated and that 117 genes were differentially regulated in the ΔslyAmutant. In the mutant strain, 111 were underexpressed and 6 overexpressed, indicating that SlyA functions mainly as an activator of transcription.

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