Direct Observation of Staphylococcus aureus Cell Wall Digestion by Lysostaphin

Unité de Chimie des Interfaces, Université Catholique de Louvain, Louvain-la-Neuve, Belgium.
Journal of bacteriology (Impact Factor: 2.81). 11/2008; 190(24):7904-9. DOI: 10.1128/JB.01116-08
Source: PubMed


The advent of Staphylococcus aureus strains that are resistant to virtually all antibiotics has increased the need for new antistaphylococcal agents. An example
of such a potential therapeutic is lysostaphin, an enzyme that specifically cleaves the S. aureus peptidoglycan, thereby lysing the bacteria. Here we tracked over time the structural and physical dynamics of single S. aureus cells exposed to lysostaphin, using atomic force microscopy. Topographic images of native cells revealed a smooth surface
morphology decorated with concentric rings attributed to newly formed peptidoglycan. Time-lapse images collected following
addition of lysostaphin revealed major structural changes in the form of cell swelling, splitting of the septum, and creation
of nanoscale perforations. Notably, treatment of the cells with lysostaphin was also found to decrease the bacterial spring
constant and the cell wall stiffness, demonstrating that structural changes were correlated with major differences in cell
wall nanomechanical properties. We interpret these modifications as resulting from the digestion of peptidoglycan by lysostaphin,
eventually leading to the formation of osmotically fragile cells. This study provides new insight into the lytic activity
of lysostaphin and offers promising prospects for the study of new antistaphylococcal agents.

Download full-text


Available from: Marie-Paule Mingeot-Leclercq
  • Source
    • "Other strategies were developed to overcome this difficulty; cells were immobilized in gelatin (Gad and Ikai 1995) or trapped into the pores of polycarbonate filters (Touhami et al. 2003a). These techniques have been widely used over the recent years (Francius et al. 2008; Alsteens et al. 2008; Dague et al. 2008b; Gilbert et al. 2007); however, it can lead to tip pollution in the case of gelatin trapping, or it can submit cells to mechanical forces in the case of cells trapped in pores. Also, both techniques are time-consuming because cells are spread all over the sample and can be quite difficult to find. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Most studies of yeast cells focus on seeing them from the “inside,” while atomic force microscopy (AFM) allows discoveries of the yeast cell wall from the “outside.” This powerful technology has allowed researchers to ask new questions about yeast cells and to give new insights into the cell wall of yeasts, from not only a morphological point of view but also a nanomechanical and functional point of view. Recent advances in AFM have made it possible to image yeast cells and to quantify their biophysical properties simultaneously. In this chapter, we first introduce the prerequisites for using AFM on yeast cells (i.e., immobilization methods). Then, we focus on the insights AFM has offered into the morphology of the yeast cell wall. In the third section, we show how nanomechanical studies of the yeast cell wall can enlighten and give important insight into complex biological phenomena. Finally, we discuss the possibility of functionalizing the AFM tip for single-molecule experiments or to measure cell–cell surface interactions.
    Full-text · Chapter · Oct 2015
  • Source
    • "Roughness of bacterium play role on the influence of van der Waals force, because it is dependent on surface area of interacting surfaces. Roughness of bacteria was investigated by Francius et al. (2008) [13]. S. aureus attachment patterns on glass surfaces with nanoscale roughness was investigated by Mitik-Dineva et al. (2009) [14]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: In order to understand the behaviour system of the bacteria it is important understand the behaviour of a single bacteria. The suspension forming bacteria may be considered as system of living active ultrafine particles (size 1 μm). Present investigation addresses to the simulation of the S. aureus bacterium-surface interactions in a framework of the Discrete Element Method (DEM). Bacterium is of the spherical shape, while the glass surface is flat and considered as elastic. In this work the theoretical model for bacteria is similar to that used for the ultrafine size stiff particles. We investigate the behaviour of the active particle by applying two known Derjaguin, Müller, Toporov (DMT) [1] and Derjaguin, Landau, Verwey, Overbeek (DLVO) [2, 3] models, which are used for simulation of ultrafine size objects. These models are enhanced by applying suggested dissipation mechanism related to the adhesion. It was assumed that energy can be dissipated and the force-displacement hysteresis can occur through the adhesion effect, where an amount of dissipated energy is fixed and independent on initial kinetic energy. This force-displacement hysteresis was observed at the physical experiments with bacteria provided by the means of the atomic force microscopy (AFM), Ubbink and Schär-Zammaretti (2007) [4]. It was illustrated that the presented adhesive-dissipative model, which applies DEM, offers the opportunity to capture dissipation effect during the contact. The numerical experiments confirm that force-displacement plots exhibit hysteresis typical to those which are observed in AFM experiments. This model can be useful for numerical simulation of interaction of bacterium to the substrate.
    Full-text · Article · Apr 2015 · Procedia Engineering
  • Source
    • "A detailed study of the surface of bacterial cells treated with batumin allows to establish significant reduction of their roughness values (Table 4). Observed values were typical for planktonic S. aureus cells[19]. Atomic force microscopy revealed qualitative and quantitative changes in the exopolymeric matrix due to batumin treatment, as well as a significant reduction in the number of cells adhered to the coverslip, preventing formation of S. aureus biofilm. It is known that some biofilms are covered by a surface film composed of lipid components similar to those in bacterial membranes which are a barrier for the penetration of antibiotics[20]. "

    Full-text · Article · Jan 2015 · Open Journal of Medical Microbiology
Show more