scholarly journals Stochastic binding of Staphylococcus aureus to hydrophobic surfaces

Soft Matter ◽  
2015 ◽  
Vol 11 (46) ◽  
pp. 8913-8919 ◽  
Author(s):  
Nicolas Thewes ◽  
Alexander Thewes ◽  
Peter Loskill ◽  
Henrik Peisker ◽  
Markus Bischoff ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Single Cell ◽  
Computational Approach ◽  
Surface Forces ◽  
Cell Wall Proteins ◽  
Cell Force ◽  
Adhesion Process

Viaa combined experimental and computational approach, the initiation of contact in the adhesion process ofS. aureusis studied. AFM single cell force spectroscopy paired with Monte Carlo simulations reveal that bacteria attach to a surface over distances far beyond the range of classical surface forcesviastochastic binding of thermally fluctuating cell wall proteins.

scholarly journals Hydrophobic interaction governs unspecific adhesion of staphylococci: a single cell force spectroscopy study

2014 ◽  
Vol 5 ◽  
pp. 1501-1512 ◽  
Author(s):  
Nicolas Thewes ◽  
Peter Loskill ◽  
Philipp Jung ◽  
Henrik Peisker ◽  
Markus Bischoff ◽  
...  
Keyword(s):  
Cell Wall ◽  
Single Cell ◽  
Hydrophobic Interaction ◽  
Force Spectroscopy ◽  
Cell Wall Proteins ◽  
Staphylococcus Carnosus ◽  
Hydrophilic Surfaces ◽  
Large Size ◽  
Abiotic Surfaces ◽  
Cell Force

Unspecific adhesion of bacteria is usually the first step in the formation of biofilms on abiotic surfaces, yet it is unclear up to now which forces are governing this process. Alongside long-ranged van der Waals and electrostatic forces, short-ranged hydrophobic interaction plays an important role. To characterize the forces involved during approach and retraction of an individual bacterium to and from a surface, single cell force spectroscopy is applied: A single cell of the apathogenic species Staphylococcus carnosus isolate TM300 is used as bacterial probe. With the exact same bacterium, hydrophobic and hydrophilic surfaces can be probed and compared. We find that as far as 50 nm from the surface, attractive forces can already be recorded, an indication of the involvement of long-ranged forces. Yet, comparing the surfaces of different surface energy, our results corroborate the model that large, bacterial cell wall proteins are responsible for adhesion, and that their interplay with the short-ranged hydrophobic interaction of the involved surfaces is mainly responsible for adhesion. The ostensibly long range of the attraction is a result of the large size of the cell wall proteins, searching for contact via hydrophobic interaction. The model also explains the strong (weak) adhesion of S. carnosus to hydrophobic (hydrophilic) surfaces.

scholarly journals Probing the Adhesion Forces of Staphylococcus aureus to Central Venous Catheters by Single-Cell Force Spectroscopy

2019 ◽  
Vol 25 (S1) ◽  
pp. 53-54
Author(s):  
Gubesh Gunaratnam ◽  
Philipp Jung ◽  
Jacqueline Willeit ◽  
Christian Spengler ◽  
Karin Jacobs ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Single Cell ◽  
Force Spectroscopy ◽  
Central Venous Catheters ◽  
Adhesion Forces ◽  
Central Venous ◽  
Cell Force

scholarly journals The adhesion capability of S. aureus cells is heterogeneously distributed over the cell envelope

2021 ◽  
Author(s):  
Christian Spengler ◽  
Bernhard A. Glatz ◽  
Erik Maikranz ◽  
Markus Bischoff ◽  
Michael Andreas Klatt ◽  
...  
Keyword(s):  
Cell Wall ◽  
Adhesive Strength ◽  
Cell Envelope ◽  
Adhesion Forces ◽  
Future Studies ◽  
Biomedical Problem ◽  
High Adhesion ◽  
Tailored Surfaces ◽  
Cell Force ◽  
Adhesion Process

AbstractUnderstanding and controlling microbial adhesion is an important biomedical problem. However, many properties of the adhesion process of bacteria are still unknown, for example the distribution of adhesive strength over the cell wall. While a patchy colloid model for adhesion has been developed recently for Gram-negative Escherichia coli cells, a comparable model for Gram-positive cells is not known. Here, we use single-cell force spectroscopy to measure the adhesion of Staphylococcus aureus at different positions on tailored surfaces. We find a heterogenous distribution of the adhesion forces with varying degrees of intensity. By comparing these results to simulations, we obtain the distribution of adhesive strength on the cell wall: The cells have several distinct spots of high adhesion capability, similar to the patchy colloid model. We discuss implications of our results for the development of new materials and the design and analysis of future studies.

scholarly journals Interaction of Staphylococcus aureus and Acinetobacter baumannii during in vitro β-lactam exposure

2021 ◽  
Author(s):  
Nicholas M. Smith ◽  
Alexa Ang ◽  
Fanny Tan ◽  
Katelyn Macias ◽  
Sarah James ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Acinetobacter Baumannii ◽  
Species Interactions ◽  
Fold Increase ◽  
Culture Conditions ◽  
Bacterial Killing ◽  
Pronounced Increase

We sought to determine if Acinetobacter baumannii is capable of altering the pharmacodynamics of an anti-staphylococcal β-lactam. Two strains of methicillin-susceptible Staphylococcus aureus (MSSA) and two A. baumannii isolates were studied in 24-h static time-killing experiments in monoculture or co-culture conditions. Bacterial killing of meropenem was described using an empiric pharmacokinetics/pharmacodynamics model that was developed using Hill functions. A mechanism-based pharmacodynamic model was also used to describe the effect of meropenem on each species of bacteria, inter-species interactions, and strain-based covariate effects. Monte Carlo simulations of bacterial killing effects were generated based on the population pharmacokinetics of meropenem in 2500 simulated critically ill subjects over 48h. Against one of the two MSSA isolates, the magnitude of bacterial killing (Edelta) decreased from -4.61 (95%CI -5.85 – -3.38) to -2.23 (95%CI -2.85 – -1.61) when cultured in the presence of carbapenem-resistant A. baumannii (CRAB). Similarly, the data were best described by a mechanism-based model where the number of A. baumannii cells produced a systematic increase in the S. aureus KC50 3.53-fold, thereby decreasing MSSA sensitivity to meropenem. A covariate effect by the CRAB resulted in a more pronounced increase in MSSA KC50 to meropenem (31.8-fold increase). However, Monte Carlo simulations demonstrated that a high intensity meropenem regimen is capable of sustained killing against both MSSA isolates despite the protection from A. baumannii. Thus, A. baumannii and MSSA engage in complex interactions during β-lactam exposure, but optimal antimicrobial dosing is likely capable of killing MSSA despite potentially beneficial interplay with A. baumannii.

scholarly journals Proteomics-Based Identification of Anchorless Cell Wall Proteins as Vaccine Candidates against Staphylococcus aureus

2009 ◽  
Vol 77 (7) ◽  
pp. 2719-2729 ◽  
Author(s):  
Eva Glowalla ◽  
Bettina Tosetti ◽  
Martin Krönke ◽  
Oleg Krut
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Survival Rates ◽  
Proteome Analysis ◽  
Surface Proteins ◽  
Human Neutrophils ◽  
Cell Wall Proteins ◽  
Lethal Challenge ◽  
Vaccine Candidates

ABSTRACT Staphylococcus aureus is an important human pathogen with increasing clinical impact due to the extensive spread of antibiotic-resistant strains. Therefore, development of a protective polyvalent vaccine is of great clinical interest. We employed an intravenous immunoglobulin (IVIG) preparation as a source of antibodies directed against anchorless S. aureus surface proteins for identification of novel vaccine candidates. In order to identify such proteins, subtractive proteome analysis (SUPRA) of S. aureus anchorless cell wall proteins was performed. Proteins reacting with IVIG but not with IVIG depleted of S. aureus-specific opsonizing antibodies were considered vaccine candidates. Nearly 40 proteins were identified by this preselection method using matrix-assisted laser desorption ionization—time of flight analysis. Three of these candidate proteins, enolase (Eno), oxoacyl reductase (Oxo), and hypothetical protein hp2160, were expressed as glutathione S-transferase fusion proteins, purified, and used for enrichment of corresponding immunoglobulin Gs from IVIG by affinity chromatography. Use of affinity-purified anti-Eno, anti-Oxo, and anti-hp2160 antibodies resulted in opsonization, phagocytosis, and killing of S. aureus by human neutrophils. High specific antibody titers were detected in mice immunized with recombinant antigens. In mice challenged with bioluminescent S. aureus, reduced staphylococcal spread was measured by in vivo imaging. The recovery of S. aureus CFU from organs of immunized mice was diminished 10- to 100-fold. Finally, mice immunized with hp2160 displayed statistically significant higher survival rates after lethal challenge with clinically relevant S. aureus strains. Taken together, our data suggest that anchorless cell wall proteins might be promising vaccine candidates and that SUPRA is a valuable tool for their identification.

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