MgrA regulates interaction of Staphylococcus aureus with mucin

AbstractBackgroundTo defend the lungs, mucus adheres to bacterial cells and facilitates their removal by ciliary transport. Our goals were to measure the affinity of mucus for the respiratory pathogen Staphylococcus aureus and identify bacterial genes that regulate this interaction.MethodsS. aureus was added to pig tracheas to determine whether it binds mucus or epithelial cells. To quantify its affinity for mucus, we developed a competition assay in microtiter plates. Mucin was added over a dose range as an inhibitor of bacterial attachment. We then examined how transcriptional regulator MgrA and cell wall transpeptidase sortase (SrtA) affect bacterial interaction with mucin.ResultsIn pig tracheas, S. aureus bound mucus strands from submucosal glands more than epithelial cells. In microtiter plate assays, ΔsrtA failed to attach even in the absence of mucin. Mucin blocked wild type S. aureus attachment in a dose-dependent manner. Higher concentrations were needed to inhibit binding of ΔmgrA. Co-deletion of ebh and sraP, which encode surface proteins repressed by MgrA, suppressed the ΔmgrA binding phenotype. No differences between ΔmgrA and wild type were observed when methylcellulose or heparin sulfate were substituted for mucin, indicating specificity.ConclusionsMucin decreases attachment of S. aureus to plastic, consistent with its physiologic role in host defense. S. aureus deficient in MgrA has decreased affinity for mucin. Ebh and SraP, which are normally repressed by MgrA, may function as inhibitors of attachment to mucin. These data show that specific bacterial factors may regulate the interaction of S. aureus with mucus.

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An Alanine-Rich Peptide Attenuates Quorum Sensing-Regulated Virulence and Biofilm Formation in Staphylococcus aureus

Journal of AOAC International ◽

10.5740/jaoacint.18-0251 ◽

2019 ◽

Vol 102 (4) ◽

pp. 1228-1234 ◽

Cited By ~ 1

Author(s):

Raid Al Akeel ◽

Ayesha Mateen ◽

Rabbani Syed

Keyword(s):

Gene Expression ◽

Staphylococcus Aureus ◽

Quorum Sensing ◽

Biofilm Formation ◽

Bacterial Attachment ◽

The Body ◽

Dependent Manner ◽

Virulence Determinants ◽

Microarray Gene Expression ◽

Concentration Dependent Manner

Abstract Background: Alanine-rich proteins/peptides (ARP), with bioactivity of up to 20 amino acid residues, can be observed by the body easily during gastrointestinal digestion. Objective: Populus trichocarpa extract’s capability to attenuate quorum sensing-regulated virulence and biofilm formation in Staphylococcus aureus is described. Methods: PT13, an ARP obtained from P. trichocarpa, was tested for its activity against S. aureus using the broth microdilution test; a crystal-violet biofilm assay was performed under a scanning electron microscope. The production of various virulence factors was estimated with PT13 treatment. Microarray gene expression profiling of PT13-treated S. aureus was conducted and compared with an untreated control. Exopolysaccharides (EPS) was estimated to observe the PT13 inhibition activity. Results: PT13 was antimicrobial toward S. aureus at different concentrations and showed a similar growth rate in the presence and absence of PT13 at concentrations ≤8 μg/mL. Biofilm production was interrupted even at low concentrations, and biofilm-related genes were down-regulated when exposed to PT13. The genes encoding cell adhesion and bacterial attachment protein were the major genes suppressed by PT13. In addition, hemolysins, clumping activity, and EPS production of S. aureus decreased after treatment in a concentration-dependent manner. Conclusions: A long-chain PT13 with effective actions that, even at low concentration levels, not only regulated the gene expression in the producer organism but also blocked the virulence gene expression in this Gram-positive human pathogen is described. Highlights: We identified a PT13 as a potential antivirulence agent that regulated production of bacterial virulence determinants (e.g., toxins, enzymes and biofilm), downwards and it may be a promising anti-virulence agent to be further developed as an anti-infective agent.

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The iron-regulated surface determinant B (IsdB) protein from Staphylococcus aureus acts as a receptor for the host protein vitronectin

Journal of Biological Chemistry ◽

10.1074/jbc.ra120.013510 ◽

2020 ◽

Vol 295 (29) ◽

pp. 10008-10022 ◽

Cited By ~ 2

Author(s):

Giampiero Pietrocola ◽

Angelica Pellegrini ◽

Mariangela J. Alfeo ◽

Loredana Marchese ◽

Timothy J. Foster ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Extracellular Matrix ◽

Matrix Protein ◽

Wide Spectrum ◽

Surface Proteins ◽

Host Protein ◽

Extracellular Matrix Protein ◽

Bacterial Cells ◽

Iron Starvation ◽

Extracellular Matrix Components

Staphylococcus aureus is an important bacterial pathogen that can cause a wide spectrum of diseases in humans and other animals. S. aureus expresses a variety of virulence factors that promote infection with this pathogen. These include cell-surface proteins that mediate adherence of the bacterial cells to host extracellular matrix components, such as fibronectin and fibrinogen. Here, using immunoblotting, ELISA, and surface plasmon resonance analysis, we report that the iron-regulated surface determinant B (IsdB) protein, besides being involved in heme transport, plays a novel role as a receptor for the plasma and extracellular matrix protein vitronectin (Vn). Vn-binding activity was expressed by staphylococcal strains grown under iron starvation conditions when Isd proteins are expressed. Recombinant IsdB bound Vn dose dependently and specifically. Both near-iron transporter motifs NEAT1 and NEAT2 of IsdB individually bound Vn in a saturable manner, with KD values in the range of 16–18 nm. Binding of Vn to IsdB was specifically blocked by heparin and reduced at high ionic strength. Furthermore, IsdB-expressing bacterial cells bound significantly higher amounts of Vn from human plasma than did an isdB mutant. Adherence to and invasion of epithelial and endothelial cells by IsdB-expressing S. aureus cells was promoted by Vn, and an αvβ3 integrin-blocking mAb or cilengitide inhibited adherence and invasion by staphylococci, suggesting that Vn acts as a bridge between IsdB and host αvβ3 integrin.

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Rosmarinic Acid Interaction with Planktonic and Biofilm Staphylococcus aureus

Natural Product Communications ◽

10.1177/1934578x1300801223 ◽

2013 ◽

Vol 8 (12) ◽

pp. 1934578X1300801 ◽

Cited By ~ 5

Author(s):

Lívia Slobodníková ◽

Silvia Fialová ◽

Helena Hupková ◽

Daniel Grančai

Keyword(s):

Staphylococcus Aureus ◽

Rosmarinic Acid ◽

Antibacterial Activities ◽

Microtiter Plate ◽

Dependent Manner ◽

Early Stages ◽

Microtiter Plates ◽

Sole Agent ◽

The Subject ◽

Biofilm Development

The subject of study was the evaluation of antibacterial activities of rosmarinic acid (RA) on clinical Staphylococcus aureus strains obtained from catheter-related infections. Minimal inhibitory (MIC) and minimal bactericidal concentrations (MBC) of RA were tested by broth microdilution assay. Biofilm-eradication activity was detected on 24-hour biofilm in microtiter plates using a regrowth technique; activity on biofilm formation was measured by a microtiter plate method after RA application to bacterial samples after 0, 1, 3 and 6 hours of biofilm development. RA had antimicrobial activity on all tested strains in concentrations from 625 to 1250 μg.mL−1 (MICs equal to MBCs). No biofilm-eradication activity on 24-hour biofilm was observed in the tested range of concentrations (from 156 to 5000 μg.mL−1). Subinhibitory RA concentrations suppressed the biofilm production, when applied at early stages of its development. Concentrations lower than subinhibitory stimulated the biofilm mass production in a concentration- and time-dependent manner. Considering our results, RA could be a candidate for a topical antimicrobial agent with killing activity on planktonic forms of bacteria and suppressing activity in the early stages of biofilm development, but probably not for the therapy of catheter-related infections as a sole agent.

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Inhibition of Staphylococcus aureus Invasion into Bovine Mammary Epithelial Cells by Contact with Live Lactobacillus casei

Applied and Environmental Microbiology ◽

10.1128/aem.03323-12 ◽

2012 ◽

Vol 79 (3) ◽

pp. 877-885 ◽

Cited By ~ 59

Author(s):

Damien S. Bouchard ◽

Lucie Rault ◽

Nadia Berkova ◽

Yves Le Loir ◽

Sergine Even

Keyword(s):

Staphylococcus Aureus ◽

Epithelial Cells ◽

Lactobacillus Casei ◽

Mammary Epithelial Cells ◽

Control Strategies ◽

Mammary Epithelial ◽

Dairy Herds ◽

Dependent Manner ◽

Content Type ◽

Bovine Mammary Epithelial Cells

ABSTRACTStaphylococcus aureusis a major pathogen that is responsible for mastitis in dairy herds.S. aureusmastitis is difficult to treat and prone to recurrence despite antibiotic treatment. The ability ofS. aureusto invade bovine mammary epithelial cells (bMEC) is evoked to explain this chronicity. One sustainable alternative to treat or prevent mastitis is the use of lactic acid bacteria (LAB) as mammary probiotics. In this study, we tested the ability ofLactobacillus caseistrains to prevent invasion of bMEC by twoS. aureusbovine strains, RF122 and Newbould305, which reproducibly induce acute and moderate mastitis, respectively.L. caseistrains affected adhesion and/or internalization ofS. aureusin a strain-dependent manner. Interestingly,L. caseiCIRM-BIA 667 reducedS. aureusNewbould305 and RF122 internalization by 60 to 80%, and this inhibition was confirmed for two otherL. caseistrains, including one isolated from bovine teat canal. The protective effect occurred without affecting bMEC morphology and viability. Once internalized, the fate ofS. aureuswas not affected byL. casei. It should be noted thatL. caseiwas internalized at a low rate but survived in bMEC cells with a better efficiency than that ofS. aureusRF122. Inhibition ofS. aureusadhesion was maintained with heat-killedL. casei, whereas contact between liveL. caseiandS. aureusor bMEC was required to preventS. aureusinternalization. This first study of the antagonism of LAB towardS. aureusin a mammary context opens avenues for the development of novel control strategies against this major pathogen.

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Protein A-Mediated Multicellular Behavior in Staphylococcus aureus

Journal of Bacteriology ◽

10.1128/jb.01222-08 ◽

2008 ◽

Vol 191 (3) ◽

pp. 832-843 ◽

Cited By ~ 170

Author(s):

Nekane Merino ◽

Alejandro Toledo-Arana ◽

Marta Vergara-Irigaray ◽

Jaione Valle ◽

Cristina Solano ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Biofilm Formation ◽

Protein A ◽

Surface Proteins ◽

Growth Media ◽

Dependent Manner ◽

Chronic Infections ◽

The Matrix ◽

Implanted Medical Devices ◽

Biofilm Development

ABSTRACT The capacity of Staphylococcus aureus to form biofilms on host tissues and implanted medical devices is one of the major virulence traits underlying persistent and chronic infections. The matrix in which S. aureus cells are encased in a biofilm often consists of the polysaccharide intercellular adhesin (PIA) or poly-N-acetyl glucosamine (PNAG). However, surface proteins capable of promoting biofilm development in the absence of PIA/PNAG exopolysaccharide have been described. Here, we used two-dimensional nano-liquid chromatography and mass spectrometry to investigate the composition of a proteinaceous biofilm matrix and identified protein A (spa) as an essential component of the biofilm; protein A induced bacterial aggregation in liquid medium and biofilm formation under standing and flow conditions. Exogenous addition of synthetic protein A or supernatants containing secreted protein A to growth media induced biofilm development, indicating that protein A can promote biofilm development without being covalently anchored to the cell wall. Protein A-mediated biofilm formation was completely inhibited in a dose-dependent manner by addition of serum, purified immunoglobulin G, or anti-protein A-specific antibodies. A murine model of subcutaneous catheter infection unveiled a significant role for protein A in the development of biofilm-associated infections, as the amount of protein A-deficient bacteria recovered from the catheter was significantly lower than that of wild-type bacteria when both strains were used to coinfect the implanted medical device. Our results suggest a novel role for protein A complementary to its known capacity to interact with multiple immunologically important eukaryotic receptors.

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Both Complement- and Fibrinogen-Dependent Mechanisms Contribute to Platelet Aggregation Mediated by Staphylococcus aureus Clumping Factor B

Infection and Immunity ◽

10.1128/iai.01993-06 ◽

2007 ◽

Vol 75 (7) ◽

pp. 3335-3343 ◽

Cited By ~ 50

Author(s):

Helen Miajlovic ◽

Anthony Loughman ◽

Marian Brennan ◽

Dermot Cox ◽

Timothy J. Foster

Keyword(s):

Staphylococcus Aureus ◽

Platelet Aggregation ◽

Platelet Rich Plasma ◽

Lag Time ◽

Dependent Manner ◽

Wild Type ◽

Factor B ◽

Fibrinogen Binding ◽

Aggregation Of Platelets ◽

Dependent Mechanism

ABSTRACT Staphylococcus aureus can stimulate activation and aggregation of platelets, which are thought to be factors in the development of infective endocarditis. Previous studies have identified clumping factor A (ClfA) and fibronectin binding proteins A and B (FnBPA and FnBPB) as potent platelet aggregators. These proteins are able to stimulate rapid platelet aggregation by either a fibrinogen- or a fibronectin-dependent process which also requires antibodies specific to each protein. Slower aggregation has been seen in other systems where specific fibrinogen binding ligands are absent and platelet aggregation is mediated by complement and specific antibodies. Bacteria expressing ClfB aggregate platelets with a longer lag time than ClfA or FnBPA and FnBPB. In order to investigate whether ClfB causes platelet aggregation in a complement- or fibrinogen-dependent manner, a non-fibrinogen-binding mutant of ClfB (ClfB Q235A) was constructed. Lactococcus lactis expressing ClfB Q235A was able to stimulate platelet aggregation in platelet-rich plasma without a significant increase in lag time. The requirements for platelet aggregation were investigated using gel-filtered platelets. Fibrinogen and specific anti-ClfB antibodies were found to be sufficient to allow platelet aggregation mediated by the wild-type ClfB protein. It seems that ClfB causes platelet aggregation by a fibrinogen-dependent mechanism. The non-fibrinogen-binding ClfB mutant was unable to stimulate platelet aggregation under these conditions. However, bacteria expressing ClfB Q235A caused platelet aggregation in a complement-dependent manner which required specific anti-ClfB antibodies.

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PYED-1 Inhibits Biofilm Formation and Disrupts the Preformed Biofilm of Staphylococcus aureus

Antibiotics ◽

10.3390/antibiotics9050240 ◽

2020 ◽

Vol 9 (5) ◽

pp. 240 ◽

Cited By ~ 1

Author(s):

Adriana Vollaro ◽

Anna Esposito ◽

Eliana Pia Esposito ◽

Raffaele Zarrilli ◽

Annalisa Guaragna ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Quorum Sensing ◽

Biofilm Formation ◽

Surface Proteins ◽

Transcriptional Analysis ◽

Capsular Polysaccharides ◽

Dependent Manner ◽

Chronic Infections ◽

Concentration Dependent Manner ◽

Expression Of Genes

Pregnadiene-11-hydroxy-16α,17α-epoxy-3,20-dione-1 (PYED-1), a heterocyclic corticosteroid derivative of deflazacort, exhibits broad-spectrum antibacterial activity against Gram-negative and Gram-positive bacteria. Here, we investigated the effect of PYED-1 on the biofilms of Staphylococcus aureus, an etiological agent of biofilm-based chronic infections such as osteomyelitis, indwelling medical device infections, periodontitis, chronic wound infections, and endocarditis. PYED-1 caused a strong reduction in biofilm formation in a concentration dependent manner. Furthermore, it was also able to completely remove the preformed biofilm. Transcriptional analysis performed on the established biofilm revealed that PYED-1 downregulates the expression of genes related to quorum sensing (agrA, RNAIII, hld, psm, and sarA), surface proteins (clfB and fnbB), secreted toxins (hla, hlb, and lukD), and capsular polysaccharides (capC). The expression of genes that encode two main global regulators, sigB and saeR, was also significantly inhibited after treatment with PYED-1. In conclusion, PYED-1 not only effectively inhibited biofilm formation, but also eradicated preformed biofilms of S. aureus, modulating the expression of genes related to quorum sensing, surface and secreted proteins, and capsular polysaccharides. These results indicated that PYED-1 may have great potential as an effective antibiofilm agent to prevent S. aureus biofilm-associated infections.

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Staphylococcus aureus adheres avidly to decellularised cardiac homograft tissue in vitro in the fibrinogen-dependent manner

Cardiology in the Young ◽

10.1017/s1047951120002772 ◽

2020 ◽

Vol 30 (12) ◽

pp. 1783-1787

Author(s):

Bartosz Ditkowski ◽

Kirsten Leeten ◽

Ramadan Jashari ◽

Elizabeth Jones ◽

Ruth Heying

Keyword(s):

Staphylococcus Aureus ◽

Valve Replacement ◽

Bacterial Adhesion ◽

Surface Composition ◽

Bacterial Attachment ◽

High Morbidity ◽

Dependent Manner ◽

Parallel Plates ◽

Fibrinogen Binding ◽

The Impact

AbstractObjective:Infective endocarditis remains a severe complication associated with a high morbidity and mortality in patients after heart valve replacement. Exploration of the pathogenesis is of high demand and we, therefore, present a competent model that allows studying bacterial adherence and the role of plasma fibrinogen in this process using a new in-house designed low-volume flow chamber. Three cardiac graft tissues used for pulmonary valve replacement have been tested under shear conditions to investigate the impact of surface composition on the adhesion events.Methods:Tissue pieces of cryopreserved homograft (non-decellularised), decellularised homograft and bovine pericardium patch were investigated for fibrinogen binding. Adherence of Staphylococcus aureus to these graft tissues was studied quantitatively under flow conditions in our newly fabricated chamber based on a parallel plates’ modality. The method of counting colony-forming units was reliable and reproducible to assess the propensity of different graft materials for bacterial attachment under shear.Results:Bacterial perfusions over all plasma-precoated tissues identified cryopreserved homograft with the lowest affinity for S. aureus compared to decellularised homograft presenting a significantly higher bacterial adhesion (p < 0.05), which was linked to a more avid fibrinogen binding (p < 0.01). Bovine pericardial patch, as a reference tissue in this study, was confirmed to be the most susceptible tissue graft for the bacterial adhesion, which was in line with our previous work.Conclusion:The two studied homograft tissues showed different levels of bacterial attachment, which might be postulated by the involvement of fibrinogen in the adhesion mechanism(s) shown previously for bovine tissues.

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Identification of ica-dependent biofilm production by Staphylococcus aureus clinical isolates and antibiofilm effects of ascorbic acid against biofilm production

Journal of Clinical Pathology ◽

10.1136/jclinpath-2019-206280 ◽

2020 ◽

Vol 73 (5) ◽

pp. 261-266

Author(s):

Sahra Kırmusaoğlu ◽

Havva Kaşıkçı

Keyword(s):

Staphylococcus Aureus ◽

Ascorbic Acid ◽

Biofilm Formation ◽

Surface Proteins ◽

Clinical Isolates ◽

High Morbidity ◽

Dependent Manner ◽

Independent Manner ◽

Biofilm Production ◽

Life Threatening

AimsStaphylococcus aureus (S. aureus) is a life-threatening pathogen with high morbidity and mortality rates which causes nosocomial and community-acquired infections. Biofilm, considered to be a common virulence factor for pathogens, plays a significant role in recurrent and untreatable infections. Biofilm formation of S. aureus is mediated by synthesis of either poly-N-acetylglucosamine in an ica-dependent manner or surface proteins in an ica-independent manner. In some cases treatment is impossible and recurrent. In this study, ica-dependent biofilm-producing S. aureus isolates were detected and the anti-biofilm effect of ascorbic acid against biofilm formation of isolates was investigated.MethodsA total of 21 methicillin-sensitive S. aureus (MSSA) clinical isolates stored in our bacterial stock were used to detect ica-dependent biofilm-producing MSSA isolates. The anti-biofilm study was undertaken with three ica-dependent biofilm-producing isolates (MSSA2–4) and ATCC 29213 (MSSA1). Biofilms and the anti-biofilm effect of ascorbic acid were detected using the microtitre plate (MtP) method. 16S-rRNA, nuc, icaA and icaD genes and expression levels of icaA and icaD of isolates were detected by RT-PCR.ResultsThe minimum inhibitory concentrations (MICs) of ascorbic acid prevented biofilm formation of MSSA1 and MSSA3. Also, 1/2 MIC of ascorbic acid prevented biofilm formation of MSSA3. It was observed that biofilm formation decreased with increased concentration. There was no significant increase in ica gene expression of MSSA1 and MSSA2. Expression of icaA and icaD of MSSA3 decreased 13% and 38%, respectively. Expression of icaA in MSSA4 decreased 12%.ConclusionThe results of our study show that ascorbic acid can be used as an anti-biofilm agent to prevent biofilm formation of S. aureus and thus biofilm-related infections.

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In Vitro Antibacterial and Antibiofilm Activity of Lippia alba Essential Oil, Citral, and Carvone against Staphylococcus aureus

The Scientific World JOURNAL ◽

10.1155/2017/4962707 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 11

Author(s):

Emanuela Mesquita Porfírio ◽

Hider Machado Melo ◽

Antônio Matheus Gomes Pereira ◽

Theodora Thays Arruda Cavalcante ◽

Geovany Amorim Gomes ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Essential Oil ◽

Microtiter Plate ◽

Antibiofilm Activity ◽

Bacterial Cells ◽

Lippia Alba ◽

Microdilution Method ◽

Aerial Parts ◽

Clinical Interest

In vitro antimicrobial and antibiofilm activities of the Lippia alba essential oil and its major components (citral and carvone) against Staphylococcus aureus were investigated. Essential oils (LA1EO, LA2EO, and LA3EO) were extracted from the aerial parts of three L. alba specimens by hydrodistillation and analyzed by gas chromatography coupled to a mass spectrometer. Minimum Inhibitory Concentrations (MIC) and Minimum Bacterial Concentration (MBC) were determined by the microdilution method. For the antibiofilm assays, the biomass formation in the biofilm was evaluated by the microtiter-plate technique with the crystal violet (CV) assay and the viability of the bacterial cells was analyzed. All oils and their major components presented antibacterial activity, and the lowest MIC and MBC values were 0.5 mg mL−1 when LA1EO and citral were used. Potential inhibition (100%) of S. aureus biofilm formation at the concentration of 0.5 mg mL−1 of all EOs was observed. However, the elimination of biofilm cells was confirmed at concentrations of 1 mg mL−1, 2 mg mL−1, 2 mg mL−1, and 0.5 mg mL−1 for LA1EO, LA2EO, LA3EO, and citral, respectively. The results obtained in the present research point to the promising antibacterial and antibiofilm potential of L. alba EOs against S. aureus, a species of recognized clinical interest.

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