scholarly journals Çeşitli Klinik Enfeksiyonlardan Elde Edilen Staphylococcus aureus Izolatlarında Insersiyon Sekansı IS256’nın Biofilm Oluşumu Üzerine Etkisi = The Role of Insertion Sequence IS256 In Biofilm Formation

2009 ◽  
Vol 62 (2) ◽  
pp. 53-57
Author(s):  
US Ebru;TEKELİ
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Insertion Sequence

scholarly journals The Teicoplanin-Associated Locus Regulator (TcaR) and the Intercellular Adhesin Locus Regulator (IcaR) Are Transcriptional Inhibitors of the ica Locus in Staphylococcus aureus

2004 ◽  
Vol 186 (8) ◽  
pp. 2449-2456 ◽  
Author(s):  
Kimberly K. Jefferson ◽  
Danielle B. Pier ◽  
Donald A. Goldmann ◽  
Gerald B. Pier
Keyword(s):  
Staphylococcus Aureus ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Negative Regulator ◽  
Regulatory Proteins ◽  
Polysaccharide Intercellular Adhesin ◽  
Topoisomerase Iv ◽  
Exogenous Factors ◽  
Dna Affinity Chromatography

ABSTRACT Infections involving Staphylococcus aureus are often more severe and difficult to treat when the organism assumes a biofilm mode of growth. The polysaccharide poly-N-acetylglucosamine (PNAG), also known as polysaccharide intercellular adhesin, is synthesized by the products of the intercellular adhesin (ica) locus and plays a key role in biofilm formation. Numerous conditions and exogenous factors influence ica transcription and PNAG synthesis, but the regulatory factors and pathways through which these environmental stimuli act have been only partially characterized. We developed a DNA affinity chromatography system to purify potential regulatory proteins that bind to the ica promoter region. Using this technique, we isolated four proteins, including the staphylococcal gene regulator SarA, a MarR family transcriptional regulator of the teicoplanin-associated locus TcaR, DNA-binding protein II, and topoisomerase IV, that bound to the ica promoter. Site-directed deletion mutagenesis of tcaR indicated that TcaR was a negative regulator of ica transcription, but deletion of tcaR alone did not induce any changes in PNAG production or in adherence to polystyrene. We also investigated the role of IcaR, encoded within the ica locus but divergently transcribed from the biosynthetic genes. As has been shown previously in Staphylococcus epidermidis, we found that IcaR was also a negative regulator of ica transcription in S. aureus. We also demonstrate that mutation of icaR augmented PNAG production and adherence to polystyrene. Transcription of the ica locus, PNAG production, and adherence to polystyrene were further increased in a tcaR icaR double mutant. In summary, TcaR appeared to be a weak negative regulator of transcription of the ica locus, whereas IcaR was a strong negative regulator, and in their absence PNAG production and biofilm formation were enhanced.

scholarly journals Cross-talk between individual phenol-soluble modulins in Staphylococcus aureus biofilm enables rapid and efficient amyloid formation

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Masihuz Zaman ◽  
Maria Andreasen
Keyword(s):  
Staphylococcus Aureus ◽  
Self Assembly ◽  
Biofilm Formation ◽  
Opportunistic Pathogen ◽  
Amyloid Formation ◽  
Secondary Nucleation ◽  
Primary Nucleation ◽  
Functional Amyloids ◽  
High Degree

The infective ability of the opportunistic pathogen Staphylococcus aureus, recognized as the most frequent cause of biofilm-associated infections, is associated with biofilm-mediated resistance to host immune response. Phenol-soluble modulins (PSM) comprise the structural scaffold of S. aureus biofilms through self-assembly into functional amyloids, but the role of individual PSMs during biofilm formation remains poorly understood and the molecular pathways of PSM self-assembly are yet to be identified. Here we demonstrate high degree of cooperation between individual PSMs during functional amyloid formation. PSMα3 initiates the aggregation, forming unstable aggregates capable of seeding other PSMs resulting in stable amyloid structures. Using chemical kinetics we dissect the molecular mechanism of aggregation of individual PSMs showing that PSMα1, PSMα3 and PSMβ1 display secondary nucleation whereas PSMβ2 aggregates through primary nucleation and elongation. Our findings suggest that various PSMs have evolved to ensure fast and efficient biofilm formation through cooperation between individual peptides.

scholarly journals Understanding the Role of the Antioxidant Drug Erdosteine and Its Active Metabolite on Staphylococcus aureus Methicillin Resistant Biofilm Formation

Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1922
Author(s):  
Cristina Cattò ◽  
Federica Villa ◽  
Francesca Cappitelli
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Active Metabolite ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Major Effect ◽  
Total Proteins ◽  
Methicillin Resistant ◽  
Biofilm Development ◽  
Open Question

Increasing numbers of researches have suggested that some drugs with reactive oxygen species (ROS)-mediated mechanisms of action modulate biofilm formation of some pathogenic strains. However, the full contribution of ROS to biofilm development is still an open question. In this paper, the correlations between the antioxidant drug Erdosteine (Er) and its active Metabolite I (Met I), ROS and biofilm development of two strains of methicillin resistant Staphylococcus aureus are presented. Experiments revealed that Er and Met I at 2 and 5 mg/L increased up to three orders of magnitude the number of biofilm-dwelling cells, while the content of ROS within the biofilms was reduced above the 87%, with a major effect of Met I in comparison to Er. Comparative proteomics showed that, 5 mg/L Met I modified the expression of 30% and 65% of total proteins in the two strains respectively. Some proteins involved in cell replication were upregulated, and a nitric oxide-based mechanism is assumed to modulate the biofilm development by changing quorum sensitive pathways. Additionally, several proteins involved in virulence were downregulated in the presence of Met I, suggesting that treated cells, despite being greater in number, might have lost part of their virulence.

scholarly journals Bap-Independent Biofilm Formation in Staphylococcus xylosus

2021 ◽  
Vol 9 (12) ◽  
pp. 2610
Author(s):  
Carolin J. Schiffer ◽  
Miriam Abele ◽  
Matthias A. Ehrmann ◽  
Rudi F. Vogel
Keyword(s):  
Staphylococcus Aureus ◽  
Functional Impairment ◽  
Congo Red ◽  
Biofilm Formation ◽  
Cell Aggregation ◽  
Protein Homology ◽  
Key Factors ◽  
Experimental Approaches ◽  
Neutral Conditions

The biofilm associated protein (Bap) is recognised as the essential component for biofilm formation in Staphylococcus aureus V329 and has been predicted as important for other species as well. Although Bap orthologs are also present in most S. xylosus strains, their contribution to biofilm formation has not yet been demonstrated. In this study, different experimental approaches were used to elucidate the effect of Bap on biofilm formation in S. xylosus and the motif structure of two biofilm-forming S. xylosus strains TMW 2.1023 and TMW 2.1523 was compared to Bap of S. aureus V329. We found that despite an identical structural arrangement into four regions, Bap from S. xylosus differs in key factors to Bap of S. aureus, i.e., isoelectric point of aggregation prone Region B, protein homology and type of repeats. Disruption of bap had no effect on aggregation behavior of selected S. xylosus strains and biofilm formation was unaffected (TMW 2.1023) or at best slightly reduced under neutral conditions (TMW 2.1523). Further, we could not observe any typical characteristics of a S. aureus Bap-positive phenotype such as functional impairment by calcium addition and rough colony morphology on congo red agar (CRA). A dominating role of Bap in cell aggregation and biofilm formation as reported mainly for S. aureus V329 was not observed. In contrast, this work demonstrates that functions of S. aureus Bap cannot easily be extrapolated to S. xylosus Bap, which appears as non-essential for biofilm formation in this species. We therefore suggest that biofilm formation in S. xylosus follows different and multifactorial mechanisms.

scholarly journals Role of Surface Protein SasG in Biofilm Formation by Staphylococcus aureus

2010 ◽  
Vol 192 (21) ◽  
pp. 5663-5673 ◽  
Author(s):  
Joan A. Geoghegan ◽  
Rebecca M. Corrigan ◽  
Dominika T. Gruszka ◽  
Pietro Speziale ◽  
James P. O'Gara ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Surface Protein ◽  
Physiological Concentration ◽  
Peptide Bonds ◽  
Limited Degree ◽  
Accumulation Phase ◽  
Domain Protein

ABSTRACT The SasG surface protein of Staphylococcus aureus has been shown to promote the formation of biofilm. SasG comprises an N-terminal A domain and repeated B domains. Here we demonstrate that SasG is involved in the accumulation phase of biofilm, a process that requires a physiological concentration of Zn2+. The B domains, but not the A domain, are required. Purified recombinant B domain protein can form dimers in vitro in a Zn2+-dependent fashion. Furthermore, the protein can bind to cells that have B domains anchored to their surface and block biofilm formation. The full-length SasG protein exposed on the cell surface is processed within the B domains to a limited degree, resulting in cleaved proteins of various lengths being released into the supernatant. Some of the released molecules associate with the surface-exposed B domains that remain attached to the cell. Studies using inhibitors and mutants failed to identify any protease that could cause the observed cleavage within the B domains. Extensively purified recombinant B domain protein is very labile, and we propose that cleavage occurs spontaneously at labile peptide bonds and that this is necessary for biofilm formation.

scholarly journals The Glycosyltransferases sdgA and sdgB Expression in Staphylococcus Epidermidis Depends On The Conditions of Biofilm Formation.

2021 ◽  
Author(s):  
Itzia S. Gómez-Alonso ◽  
Ilse D. Estrada-Alemán ◽  
Sergio Martínez-García ◽  
Humberto Peralta ◽  
Erika T. Quintana ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Cathepsin G ◽  
Dynamic Conditions ◽  
Static Conditions ◽  
Sessile Cells ◽  
In Cells

Abstract The Staphylococcus aureus’ SdrG protein is glycosylated by SdgA and SdgB for their protection against its degradation by the neutrophil’s cathepsin G. So far, there is not information about the role of Staphylococcus epidermidis’ SdgA nor SdgB in the production of biofilm, therefore the main of this work was to determine the distribution and expression of sdrG, sdgA and sdgB genes in S. epidermidis in conditions of biofilm. The frequency of the genes sdrG, sdgA and sdgB were evaluated by PCR in a collection of 75 isolates. The isolates were grown in dynamic conditions (in agitation) or static conditions (biofilm productor: planktonic or sessile cells). The expression of sdrG, sdgA and sdgB were determined by RT-qPCR in cells grown under dynamic conditions (CGDC), as well as planktonic and sessile cells, and in cells adhered to a catheter (in vivo). The genes sdrG and sdgB were detected in 100% of isolates, meanwhile the gene sdgA was detected in 71% of the samples (p<0.001). The CGDC did not expressed the sdrG, sdgA and sdgB mRNAs. The planktonic and sessile cells expressed sdrG and sdgB, and the same was seen in cells adhered to the catheter. In particular, one isolate, able to induce biofilm under cathepsin G treatment, expressed sdrG and sdgB in planktonic, sessile and in cells adhered to the catheter. This suggests that the state of cells adherence is an important factor for the transcription of sdgA, sdgB and sdrG.

scholarly journals An Electrostatic Net Model for the Role of Extracellular DNA in Biofilm Formation by Staphylococcus aureus

2015 ◽  
Vol 197 (24) ◽  
pp. 3779-3787 ◽  
Author(s):  
Vanina Dengler ◽  
Lucy Foulston ◽  
Alicia S. DeFrancesco ◽  
Richard Losick
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Extracellular Dna ◽  
Matrix Proteins ◽  
Exogenous Dna ◽  
Content Type ◽  
Cytoplasmic Proteins ◽  
The Matrix ◽  
Biofilm Matrix

ABSTRACTStaphylococcus aureusis an important human pathogen that can form biofilms on various surfaces. These cell communities are protected from the environment by a self-produced extracellular matrix composed of proteins, DNA, and polysaccharide. The exact compositions and roles of the different components are not fully understood. In this study, we investigated the role of extracellular DNA (eDNA) and its interaction with the recently identified cytoplasmic proteins that have a moonlighting role in the biofilm matrix. These matrix proteins associate with the cell surface upon the drop in pH that naturally occurs during biofilm formation, and we found here that this association is independent of eDNA. Conversely, the association of eDNA with the matrix was dependent on matrix proteins. Both proteinase and DNase treatments severely reduced clumping of resuspended biofilms; highlighting the importance of both proteins and eDNA in connecting cells together. By adding an excess of exogenous DNA to DNase-treated biofilm, clumping was partially restored, confirming the crucial role of eDNA in the interconnection of cells. On the basis of our results, we propose that eDNA acts as an electrostatic net, interconnecting cells surrounded by positively charged matrix proteins at a low pH.IMPORTANCEExtracellular DNA (eDNA) is an important component of the biofilm matrix of diverse bacteria, but its role in biofilm formation is not well understood. Here we report that inStaphylococcus aureus, eDNA associates with cells in a manner that depends on matrix proteins and that eDNA is required to link cells together in the biofilm. These results confirm previous studies that showed that eDNA is an important component of theS. aureusbiofilm matrix and also suggest that eDNA acts as an electrostatic net that tethers cells together via the proteinaceous layer of the biofilm matrix.

scholarly journals Mutation of traP in Staphylococcus aureus Has No Impact on Expression of agr or Biofilm Formation

2007 ◽  
Vol 75 (9) ◽  
pp. 4528-4533 ◽  
Author(s):  
Laura H. Tsang ◽  
Sonja T. Daily ◽  
Elizabeth C. Weiss ◽  
Mark S. Smeltzer
Keyword(s):  
Staphylococcus Aureus ◽  
Hemolytic Activity ◽  
Biofilm Formation ◽  
Laboratory Strain ◽  
Clinical Isolates ◽  
Regulatory Role ◽  
Accessory Gene ◽  
Accessory Gene Regulator ◽  
Affect Expression

ABSTRACT To investigate the regulatory role of traP (target of RNAIII-activating peptide) in Staphylococcus aureus, we generated traP mutations in the clinical isolates UAMS-1 and USA300. In neither case did mutation of traP affect expression of the accessory gene regulator (agr) or the ability to form a biofilm. We were also unable to confirm that mutation of traP in the prototype 8325-4 laboratory strain RN6390 results in reduced expression of agr, reduced hemolytic activity, or an altered capacity to form a biofilm.

scholarly journals The role of Staphylococcus aureus surface protein SasG in adherence and biofilm formation

Microbiology ◽  
2007 ◽  
Vol 153 (8) ◽  
pp. 2435-2446 ◽  
Author(s):  
Rebecca M. Corrigan ◽  
David Rigby ◽  
Pauline Handley ◽  
Timothy J. Foster
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Surface Protein
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