scholarly journals Changes in the Expression of Biofilm-Associated Surface Proteins inStaphylococcus aureusFood-Environmental Isolates Subjected to Sublethal Concentrations of Disinfectants

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Lenka Cincarova ◽  
Ondrej Polansky ◽  
Vladimir Babak ◽  
Pavel Kulich ◽  
Petr Kralik
Keyword(s):  
Biofilm Formation ◽  
Protein A ◽  
Surface Proteins ◽  
Bacterial Cells ◽  
Abiotic Surfaces ◽  
Immunoglobulin Binding Protein ◽  
Chloramine T ◽  
Nucleic Acid Stain ◽  
Immunoglobulin Binding ◽  
Sublethal Concentrations

Sublethal concentrations (sub-MICs) of certain disinfectants are no longer effective in removing biofilms from abiotic surfaces and can even promote the formation of biofilms. Bacterial cells can probably adapt to these low concentrations of disinfectants and defend themselves by way of biofilm formation. In this paper, we report on threeStaphylococcus aureusbiofilm formers (strong B+++, moderate B++, and weak B+) that were cultivated with sub-MICs of commonly used disinfectants, ethanol or chloramine T, and quantified using Syto9 green fluorogenic nucleic acid stain. We demonstrate that 1.25–2.5% ethanol and 2500 μg/mL chloramine T significantly enhancedS. aureusbiofilm formation. To visualize differences in biofilm compactness betweenS. aureusbiofilms in control medium, 1.25% ethanol, or 2500 μg/mL chloramine T, scanning electron microscopy was used. To describe changes in abundance of surface-exposed proteins in ethanol- or chloramine T-treated biofilms, surface proteins were prepared using a novel trypsin shaving approach and quantified after dimethyl labeling by LC-LTQ/Orbitrap MS. Our data show that some proteins with adhesive functions and others with cell maintenance functions and virulence factor EsxA were significantly upregulated by both treatments. In contrast, immunoglobulin-binding protein A was significantly downregulated for both disinfectants. Significant differences were observed in the effect of the two disinfectants on the expression of surface proteins including some adhesins, foldase protein PrsA, and two virulence factors.

Antibiotics Application Strategies to Control Biofilm Formation in Pathogenic Bacteria

2020 ◽  
Vol 21 (4) ◽  
pp. 270-286 ◽  
Author(s):  
Fazlurrahman Khan ◽  
Dung T.N. Pham ◽  
Sandra F. Oloketuyi ◽  
Young-Mog Kim
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Extracellular Polymeric Substances ◽  
Quorum Quenching ◽  
Resistance Mechanisms ◽  
Bacterial Biofilm ◽  
Bacterial Cells ◽  
High Concentration ◽  
Biofilm Inhibition ◽  
Abiotic Surfaces

Background: The establishment of a biofilm by most pathogenic bacteria has been known as one of the resistance mechanisms against antibiotics. A biofilm is a structural component where the bacterial community adheres to the biotic or abiotic surfaces by the help of Extracellular Polymeric Substances (EPS) produced by bacterial cells. The biofilm matrix possesses the ability to resist several adverse environmental factors, including the effect of antibiotics. Therefore, the resistance of bacterial biofilm-forming cells could be increased up to 1000 times than the planktonic cells, hence requiring a significantly high concentration of antibiotics for treatment. Methods: Up to the present, several methodologies employing antibiotics as an anti-biofilm, antivirulence or quorum quenching agent have been developed for biofilm inhibition and eradication of a pre-formed mature biofilm. Results: Among the anti-biofilm strategies being tested, the sub-minimal inhibitory concentration of several antibiotics either alone or in combination has been shown to inhibit biofilm formation and down-regulate the production of virulence factors. The combinatorial strategies include (1) combination of multiple antibiotics, (2) combination of antibiotics with non-antibiotic agents and (3) loading of antibiotics onto a carrier. Conclusion: The present review paper describes the role of several antibiotics as biofilm inhibitors and also the alternative strategies adopted for applications in eradicating and inhibiting the formation of biofilm by pathogenic bacteria.

scholarly journals Genetic Analysis of Functions Involved in Adhesion of Pseudomonas putida to Seeds

2000 ◽  
Vol 182 (9) ◽  
pp. 2363-2369 ◽  
Author(s):  
Manuel Espinosa-Urgel ◽  
Amparo Salido ◽  
Juan-Luis Ramos
Keyword(s):  
Pseudomonas Putida ◽  
Calcium Binding ◽  
Efflux Pump ◽  
Protein A ◽  
Surface Proteins ◽  
Peptide Transporter ◽  
Multidrug Efflux Pump ◽  
Bacterial Populations ◽  
Abiotic Surfaces ◽  
Initial Seed

ABSTRACT Many agricultural uses of bacteria require the establishment of efficient bacterial populations in the rhizosphere, for which colonization of plant seeds often constitutes a critical first step.Pseudomonas putida KT2440 is a strain that colonizes the rhizosphere of a number of agronomically important plants at high population densities. To identify the functions involved in initial seed colonization by P. putida KT2440, we subjected this strain to transposon mutagenesis and screened for mutants defective in attachment to corn seeds. Eight different mutants were isolated and characterized. While all of them showed reduced attachment to seeds, only two had strong defects in their adhesion to abiotic surfaces (glass and different plastics). Sequences of the loci affected in all eight mutants were obtained. None of the isolated genes had previously been described in P. putida, although four of them showed clear similarities with genes of known functions in other organisms. They corresponded to putative surface and membrane proteins, including a calcium-binding protein, a hemolysin, a peptide transporter, and a potential multidrug efflux pump. One other showed limited similarities with surface proteins, while the remaining three presented no obvious similarities with known genes, indicating that this study has disclosed novel functions.

scholarly journals Application of Bacteriophages on Shiga Toxin-Producing Escherichia coli (STEC) Biofilm

Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1423
Author(s):  
Nicola Mangieri ◽  
Roberto Foschino ◽  
Claudia Picozzi
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Bacterial Cells ◽  
Abiotic Surfaces ◽  
Continuous Presence ◽  
Different Strains ◽  
Better Than

Shiga toxin-producing Escherichia coli are pathogenic bacteria able to form biofilms both on abiotic surfaces and on food, thus increasing risks for food consumers. Moreover, biofilms are difficult to remove and more resistant to antimicrobial agents compared to planktonic cells. Bacteriophages, natural predators of bacteria, can be used as an alternative to prevent biofilm formation or to remove pre-formed biofilm. In this work, four STEC able to produce biofilm were selected among 31 different strains and tested against single bacteriophages and two-phage cocktails. Results showed that our phages were able to reduce biofilm formation by 43.46% both when used as single phage preparation and as a cocktail formulation. Since one of the two cocktails had a slightly better performance, it was used to remove pre-existing biofilms. In this case, the phages were unable to destroy the biofilms and reduce the number of bacterial cells. Our data confirm that preventing biofilm formation in a food plant is better than trying to remove a preformed biofilm and the continuous presence of bacteriophages in the process environment could reduce the number of bacteria able to form biofilms and therefore improve the food safety.

Characterization of endoplasmic reticulum by co-localization of BiP and dicarbocyanine dyes

1992 ◽  
Vol 101 (2) ◽  
pp. 315-322 ◽  
Author(s):  
M. Terasaki ◽  
T.S. Reese
Keyword(s):  
Endoplasmic Reticulum ◽  
Cultured Cells ◽  
Protein A ◽  
Epithelial Cell Line ◽  
Cultured Fibroblasts ◽  
Whole Cells ◽  
Membrane Compartments ◽  
Immunoglobulin Binding Protein ◽  
Immunoglobulin Binding ◽  
Peripheral Regions

The original concept of endoplasmic reticulum derived from the observation of a reticular network in cultured fibroblasts by electron microscopy of whole cells. It was previously reported that the fluorescent dye, DiOC6(3), stains a similar network as well as mitochondria and other organelles in living cells. Here, we investigate the significance of the structures labeled by DiO6(3) in CV-1 cells, a monkey epithelial cell line. First, we show that the network stained in living CV-1 cells is preserved by glutaraldehyde fixation and then we co-label it with an antibody against BiP (immunoglobulin binding protein), a protein commonly accepted to be present in the endoplasmic reticulum. Anti-BiP labeled the same network as that labeled by DiOC6(3), so this network now is identified as being part of the endoplasmic reticulum. DiOC6(3) labels many other membrane compartments in addition to the endoplasmic reticulum. This, along with its lipophilic properties, suggests that DiOC6(3) stains all intracellular membranes. However, the extensive reticular network in the thin peripheral regions of cultured cells is easily distinguished from these other membranes. Thus, staining by DiOC6(3) is a useful method for localizing the endoplasmic reticulum, particularly in thin peripheral regions of cultured cells.

scholarly journals Revisiting Bap Multidomain Protein: More Than Sticking Bacteria Together

2020 ◽  
Vol 11 ◽  
Author(s):  
Jaione Valle ◽  
Xianyang Fang ◽  
Iñigo Lasa
Keyword(s):  
Biofilm Formation ◽  
Core Genome ◽  
Current Knowledge ◽  
Surface Proteins ◽  
Structure And Properties ◽  
Diverse Range ◽  
The Core ◽  
Self Assembling ◽  
Abiotic Surfaces ◽  
Range Of Functions

One of the major components of the staphylococcal biofilm is surface proteins that assemble as scaffold components of the biofilm matrix. Among the different surface proteins able to contribute to biofilm formation, this review is dedicated to the Biofilm Associated Protein (Bap). Bap is part of the accessory genome of Staphylococcus aureus but orthologs of Bap in other staphylococcal species belong to the core genome. When present, Bap promotes adhesion to abiotic surfaces and induces strong intercellular adhesion by self-assembling into amyloid like aggregates in response to the levels of calcium and the pH in the environment. During infection, Bap enhances the adhesion to epithelial cells where it binds directly to the host receptor Gp96 and inhibits the entry of the bacteria into the cells. To perform such diverse range of functions, Bap comprises several domains, and some of them include several motifs associated to distinct functions. Based on the knowledge accumulated with the Bap protein of S. aureus, this review aims to summarize the current knowledge of the structure and properties of each domain of Bap and their contribution to Bap functionality.

scholarly journals Protein A-Mediated Multicellular Behavior in Staphylococcus aureus

2008 ◽  
Vol 191 (3) ◽  
pp. 832-843 ◽  
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.

scholarly journals Deciphering Streptococcal Biofilms

2020 ◽  
Vol 8 (11) ◽  
pp. 1835
Author(s):  
Puja Yadav ◽  
Shalini Verma ◽  
Richard Bauer ◽  
Monika Kumari ◽  
Meenakshi Dua ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Biofilm Formation ◽  
Expression Patterns ◽  
Initial Step ◽  
Molecular Techniques ◽  
Surface Proteins ◽  
Considerable Proportion ◽  
Bacterial Cells ◽  
Bacterial Survival ◽  
Biofilm Growth

Streptococci are a diverse group of bacteria, which are mostly commensals but also cause a considerable proportion of life-threatening infections. They colonize many different host niches such as the oral cavity, the respiratory, gastrointestinal, and urogenital tract. While these host compartments impose different environmental conditions, many streptococci form biofilms on mucosal membranes facilitating their prolonged survival. In response to environmental conditions or stimuli, bacteria experience profound physiologic and metabolic changes during biofilm formation. While investigating bacterial cells under planktonic and biofilm conditions, various genes have been identified that are important for the initial step of biofilm formation. Expression patterns of these genes during the transition from planktonic to biofilm growth suggest a highly regulated and complex process. Biofilms as a bacterial survival strategy allow evasion of host immunity and protection against antibiotic therapy. However, the exact mechanisms by which biofilm-associated bacteria cause disease are poorly understood. Therefore, advanced molecular techniques are employed to identify gene(s) or protein(s) as targets for the development of antibiofilm therapeutic approaches. We review our current understanding of biofilm formation in different streptococci and how biofilm production may alter virulence-associated characteristics of these species. In addition, we have summarized the role of surface proteins especially pili proteins in biofilm formation. This review will provide an overview of strategies which may be exploited for developing novel approaches against biofilm-related streptococcal infections.

scholarly journals Protein A Is Released into the Staphylococcus aureus Culture Supernatant with an Unprocessed Sorting Signal

2015 ◽  
Vol 83 (4) ◽  
pp. 1598-1609 ◽  
Author(s):  
Dara P. O'Halloran ◽  
Kieran Wynne ◽  
Joan A. Geoghegan
Keyword(s):  
Staphylococcus Aureus ◽  
Protein A ◽  
Covalent Attachment ◽  
Sortase A ◽  
Reporter Protein ◽  
Extracellular Medium ◽  
Content Type ◽  
Sorting Signal ◽  
Immunoglobulin Binding Protein ◽  
Immunoglobulin Binding

The immunoglobulin binding protein A (SpA) ofStaphylococcus aureusis synthesized as a precursor with a C-terminal sorting signal. The sortase A enzyme mediates covalent attachment to peptidoglycan so that SpA is displayed on the surface of the bacterium. Protein A is also found in the extracellular medium, but the processes involved in its release are not fully understood. Here, we show that a portion of SpA is released into the supernatant with an intact sorting signal, indicating that it has not been processed by sortase A. Release of SpA was reduced when the native sorting signal of SpA was replaced with the corresponding region of another sortase-anchored protein (SdrE). Similarly, a reporter protein fused to the sorting signal of SpA was released to a greater extent than the same polypeptide fused to the SdrE sorting signal. Released SpA protected bacteria from killing in human blood, indicating that it contributes to immune evasion.

scholarly journals Staphylococcus aureus Fibronectin-Binding Protein A Mediates Cell-Cell Adhesion through Low-Affinity Homophilic Bonds

mBio ◽  
2015 ◽  
Vol 6 (3) ◽  
Author(s):  
Philippe Herman-Bausier ◽  
Sofiane El-Kirat-Chatel ◽  
Timothy J. Foster ◽  
Joan A. Geoghegan ◽  
Yves F. Dufrêne
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Surface ◽  
Biofilm Formation ◽  
Protein A ◽  
Intercellular Adhesion ◽  
Surface Proteins ◽  
Content Type ◽  
Fibronectin Binding ◽  
A Domains ◽  
Cell Cell

ABSTRACT Staphylococcus aureus is an important opportunistic pathogen which is a leading cause of biofilm-associated infections on indwelling medical devices. The cell surface-located fibronectin-binding protein A (FnBPA) plays an important role in the accumulation phase of biofilm formation by methicillin-resistant S. aureus (MRSA), but the underlying molecular interactions are not yet established. Here, we use single-cell and single-molecule atomic force microscopy to unravel the mechanism by which FnBPA mediates intercellular adhesion. We show that FnBPA is responsible for specific cell-cell interactions that involve the FnBPA A domain and cause microscale cell aggregation. We demonstrate that the strength of FnBPA-mediated adhesion originates from multiple low-affinity homophilic interactions between FnBPA A domains on neighboring cells. Low-affinity binding by means of FnBPA may be important for biofilm dynamics. These results provide a molecular basis for the ability of FnBPA to promote cell accumulation during S. aureus biofilm formation. We speculate that homophilic interactions may represent a generic strategy among staphylococcal cell surface proteins for guiding intercellular adhesion. As biofilm formation by MRSA strains depends on proteins rather than polysaccharides, our approach offers exciting prospects for the design of drugs or vaccines to inhibit protein-dependent intercellular interactions in MRSA biofilms. IMPORTANCE Staphylococcus aureus is a human pathogen that forms biofilms on indwelling medical devices, such as central venous catheters and prosthetic joints. This leads to biofilm infections that are difficult to treat with antibiotics because many cells within the biofilm matrix are dormant. The fibronectin-binding proteins (FnBPs) FnBPA and FnBPB promote biofilm formation by clinically relevant methicillin-resistant S. aureus (MRSA) strains, but the molecular mechanisms involved remain poorly understood. We used atomic force microscopy techniques to demonstrate that FnBPA mediates cell-cell adhesion via multiple, low-affinity homophilic bonds between FnBPA A domains on adjacent cells. Therefore, FnBP-mediated homophilic interactions represent an interesting target to prevent MRSA biofilms. We propose that such homophilic mechanisms may be widespread among staphylococcal cell surface proteins, providing a means to guide intercellular adhesion and biofilm accumulation.

scholarly journals Equilibrium and pre-equilibrium fluorescence spectroscopic studies of the binding of a single-immunoglobulin-binding domain derived from protein G to the Fc fragment from human IgG1

1995 ◽  
Vol 310 (1) ◽  
pp. 177-184 ◽  
Author(s):  
K N Walker ◽  
S P Bottomley ◽  
A G Popplewell ◽  
B J Sutton ◽  
M G Gore
Keyword(s):  
Protein A ◽  
Spectroscopic Studies ◽  
Binding Domain ◽  
Protein G ◽  
Binding Interaction ◽  
Fc Fragment ◽  
Igg Binding ◽  
Immunoglobulin Binding Protein ◽  
Human Igg1 ◽  
Immunoglobulin Binding

A single-immunoglobulin-binding protein based upon the C2 domain of Protein G from Streptococcus has been shown to bind tightly to the Fc fragment of IgG1. The binding interaction results in a decrease in the fluorescence intensity from the sole Trp residue (Trp-48) in this domain. This spectral change has been used to monitor the binding interactions between the two proteins using equilibrium and pre-equilibrium fluorescence spectroscopy. Comparison of the data from the two techniques suggests that a conformational change occurs after the initial formation of the complex. Mutagenesis studies have shown that the Trp residue is important for binding and that replacement by a Phe residue is important for binding and that replacement by a Phe residue leads to a 300-fold decrease in the affinity for Fc gamma 1. Determination of the rate constants kon and koff at different values of pH between 4.0 and 9.0 suggest that variations in Kd are mediated predominantly by changes in kon. Competition experiments between SpG1 and a single-IgG-binding domain from Protein A from Staphylococcus aureus have been used to determine the affinity of the latter for Fc gamma 1.

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