scholarly journals Characterizing the relationship between Sortase A-dependent substrates and the consequences of Srta deletion in Enterococcus faecalis

2017 ◽  
Author(s):  
◽  
Irina Afonina
Keyword(s):  
Enterococcus Faecalis ◽  
Sortase A ◽  
The Relationship

Screening of curcumin analogues targeting Sortase A enzyme of Enterococcus faecalis: a molecular dynamics approach

2019 ◽  
Vol 10 (3) ◽  
pp. 245-255
Author(s):  
Muthusaravanan Sivaramakrishnan ◽  
Vivek Jagadeesan Sharavanan ◽  
D. Ruban Durairaj ◽  
Kumaravel Kandaswamy ◽  
Shanmughavel Piramanayagam ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Enterococcus Faecalis ◽  
Sortase A ◽  
Curcumin Analogues

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

2009 ◽  
Vol 191 (10) ◽  
pp. 3237-3247 ◽  
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.

scholarly journals The Enterococcal Surface Protein, Esp, Is Involved in Enterococcus faecalis Biofilm Formation

2001 ◽  
Vol 67 (10) ◽  
pp. 4538-4545 ◽  
Author(s):  
Alejandro Toledo-Arana ◽  
Jaione Valle ◽  
Cristina Solano ◽  
Marı́a Jesús Arrizubieta ◽  
Carme Cucarella ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Biofilm Formation ◽  
Insertional Mutagenesis ◽  
Surface Protein ◽  
Structural Similarity ◽  
Abiotic Surfaces ◽  
Polyvinyl Chloride Plastic ◽  
Primary Attachment ◽  
Encoding Gene ◽  
The Relationship

ABSTRACT The enterococcal surface protein, Esp, is a high-molecular-weight surface protein of unknown function whose frequency is significantly increased among infection-derived Enterococcus faecalisisolates. In this work, a global structural similarity was found between Bap, a biofilm-associated protein of Staphylococcus aureus, and Esp. Analysis of the relationship between the presence of the Esp-encoding gene (esp) and the biofilm formation capacity in E. faecalis demonstrated that the presence of the esp gene is highly associated (P < 0.0001) with the capacity of E. faecalis to form a biofilm on a polystyrene surface, since 93.5% of the E. faecalis esp-positive isolates were capable of forming a biofilm. Moreover, none of the E. faecalis esp-deficient isolates were biofilm producers. Depending on theE. faecalis isolate, insertional mutagenesis ofesp caused either a complete loss of the biofilm formation phenotype or no apparent phenotypic defect. Complementation studies revealed that Esp expression in an E. faecalis esp-deficient strain promoted primary attachment and biofilm formation on polystyrene and polyvinyl chloride plastic from urine collection bags. Together, these results demonstrate that (i) biofilm formation capacity is widespread among clinical E. faecalis isolates, (ii) the biofilm formation capacity is restricted to the E. faecalis strains harboringesp, and (iii) Esp promotes primary attachment and biofilm formation of E. faecalis on abiotic surfaces.

scholarly journals Contribution of Autolysin and Sortase A during Enterococcus faecalis DNA-Dependent Biofilm Development

2009 ◽  
Vol 77 (9) ◽  
pp. 3626-3638 ◽  
Author(s):  
Pascale S. Guiton ◽  
Chia S. Hung ◽  
Kimberly A. Kline ◽  
Robyn Roth ◽  
Andrew L. Kau ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Laser Scanning ◽  
Developmental Stages ◽  
Extracellular Dna ◽  
Confocal Laser ◽  
Sortase A ◽  
Hydrodynamic Conditions ◽  
Biofilm Production ◽  
Dna Release ◽  
Biofilm Development

ABSTRACT Biofilm production is a major attribute of Enterococcus faecalis clinical isolates. Although some factors, such as sortases, autolysin, and extracellular DNA (eDNA), have been associated with E. faecalis biofilm production, the mechanisms underlying the contributions of these factors to this process have not been completely elucidated yet. In this study we define important roles for the major E. faecalis autolysin (Atn), eDNA, and sortase A (SrtA) during the developmental stages of biofilm formation under static and hydrodynamic conditions. Deletion of srtA affects the attachment stage and results in a deficiency in biofilm production. Atn-deficient mutants are delayed in biofilm development due to defects in primary adherence and DNA release, which we show to be particularly important during the accumulative phase for maturation and architectural stability of biofilms. Confocal laser scanning and freeze-dry electron microscopy of biofilms grown under hydrodynamic conditions revealed that E. faecalis produces a DNase I-sensitive fibrous network, which is important for biofilm stability and is absent in atn-deficient mutant biofilms. This study establishes the stage-specific requirements for SrtA and Atn and demonstrates a role for Atn in the pathway leading to DNA release during biofilm development in E. faecalis.

scholarly journals Replication of Enterococcus faecalis Pheromone-Responding Plasmid pAD1: Location of the Minimal Replicon and oriV Site and RepA Involvement in Initiation of Replication

2004 ◽  
Vol 186 (15) ◽  
pp. 5003-5016 ◽  
Author(s):  
Maria Victoria Francia ◽  
Shuhei Fujimoto ◽  
Patricia Tille ◽  
Keith E. Weaver ◽  
Don B. Clewell
Keyword(s):  
Enterococcus Faecalis ◽  
Copy Number ◽  
Replication Origin ◽  
Plasmid Vector ◽  
Small Segment ◽  
Initiator Protein ◽  
Repeat Sequences ◽  
Initiation Of Replication ◽  
Relationship Of ◽  
The Relationship

ABSTRACT The hemolysin-determining plasmid pAD1 is a member of a widely disseminated family of highly conjugative elements commonly present in clinical isolates of Enterococcus faecalis. The determinants repA, repB, and repC, as well as adjacent iteron sequences, are believed to play important roles in pAD1 replication and maintenance. The repA gene encodes an initiator protein, whereas repB and repC encode proteins related to stability and copy number. The present study focuses specifically on repA and identifies a replication origin (oriV) within a central region of the repA determinant. A small segment of repA carrying oriV was able to support replication in cis of a plasmid vector otherwise unable to replicate, if an intact RepA was supplied in trans. We demonstrate that under conditions in which RepA is expressed from an artificial promoter, a segment of DNA carrying only repA is sufficient for stable replication in E. faecalis. We also show that RepA binds specifically to oriV DNA at several sites containing inverted repeat sequences (i.e., IR-1) and nonspecifically to single-stranded DNA, and related genetic analyses confirm that these sequences play an important role in replication. Finally, we reveal a relationship between the internal structure of RepA and its ability to recognize oriV. An in-frame deletion within repA resulting in loss of 105 nucleotides, including at least part of oriV, did not eliminate the ability of the altered RepA protein to initiate replication using an intact origin provided in trans. The relationship of RepA to other known initiator proteins is also discussed.

scholarly journals In Vitro Synergism of Penicillin and Ceftriaxone against Enterococcus faecalis

2021 ◽  
Vol 9 (10) ◽  
pp. 2150
Author(s):  
Lara Thieme ◽  
Simon Briggs ◽  
Eamon Duffy ◽  
Oliwia Makarewicz ◽  
Mathias W. Pletz
Keyword(s):  
Infective Endocarditis ◽  
Combination Therapy ◽  
Enterococcus Faecalis ◽  
Synergistic Effects ◽  
Case Series ◽  
Standard Strain ◽  
Parenteral Antibiotic ◽  
Trough Concentrations ◽  
The Relationship

Enterococcus faecalis infective endocarditis is commonly treated with intravenous ampicillin/ceftriaxone combination therapy. Ampicillin, however, is unsuitable for outpatient parenteral antibiotic therapy (OPAT) regimens due to its instability in 24 h continuous infusors, and has been successfully replaced by benzylpenicillin used together with ceftriaxone in a few small case series. Since in vitro synergy data of penicillin/ceftriaxone against E. faecalis are still lacking, checkerboard assays were performed for 28 clinical E. faecalis isolates and one laboratory standard strain. Synergistic effects (both lowest and median FICI) were observed for penicillin/ceftriaxone in 15/29 isolates, while ampicillin/ceftriaxone exhibited synergism in 22/29 isolates. For isolates with ceftriaxone MICs ≤ 256 mg/L, the addition of free ceftriaxone trough concentrations to penicillin or ampicillin resulted in comparable synergistic effects for both combinations. In contrast, for isolates with ceftriaxone MICs ≥ 512 mg/L free ceftriaxone trough concentrations were only sufficient to exhibit synergistic effects in combination with ampicillin, but not penicillin. This study suggests that benzylpenicillin/ceftriaxone would be expected to be suitable for the OPAT treatment of enterococcal endocarditis for E. faecalis isolates with ceftriaxone MICs ≤ 256 mg/L. However, combination therapy would be expected to provide no advantage over benzylpenicillin monotherapy for isolates with ceftriaxone MICs ≥ 512 mg/L. Further investigation is required to analyse the relationship between ceftriaxone susceptibility and penicillin/ceftriaxone synergy, especially for isolates with ceftriaxone MICs of 64 to 512 mg/L.

scholarly journals Enterococcus faecalis bloodstream infection: does infectious disease specialist consultation make a difference?

Infection ◽  
2021 ◽  
Author(s):  
Chiara Cattaneo ◽  
Siegbert Rieg ◽  
Guido Schwarzer ◽  
Matthias C. Müller ◽  
Benjamin Blümel ◽  
...  
Keyword(s):  
Bloodstream Infection ◽  
Enterococcus Faecalis ◽  
Care Center ◽  
Tertiary Care ◽  
Multivariate Logistic Regression ◽  
Specialist Consultation ◽  
Focus Of Infection ◽  
The Relationship ◽  
Disease Specialist

Abstract Purpose To evaluate the relationship between mortality or relapse of bloodstream infection (BSI) due to Enterococcus faecalis and infectious diseases specialist consultation (IDC) and other factors potentially associated with outcomes. Methods In a tertiary-care center, consecutive adult patients with E. faecalis BSI between January 1, 2016 and January 31, 2019, were prospectively followed. The management of E. faecalis BSI was evaluated in terms of adherence to evidence-based quality-of-care indicators (QCIs). IDC and other factors potentially associated with 90-day-mortality or relapse of E. faecalis BSI were analyzed by multivariate logistic regression. Results A total of 151 patients with a median age of 68 years were studied. IDC was performed in 38% of patients with E. faecalis BSI. 30 cases of endocarditis (20%) were diagnosed. All-cause in-hospital mortality was 23%, 90-day mortality was 37%, and 90-day relapsing E. faecalis BSI was 8%. IDC was significantly associated with better adherence to 5 QCIs. Factors significantly associated with 90-day mortality or relapsing EfB in multivariate analysis were severe sepsis or septic shock at onset (HR 4.32, CI 2.36e7.88) and deep-seated focus of infection (superficial focus HR 0.33, CI 0.14e0.76). Conclusion Enterococcus faecalis bacteremia is associated with a high mortality. IDC contributed to improved diagnostic and therapeutic management.

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