Nanoscale Cell Wall Deformation Impacts Long-Range Bacterial Adhesion Forces on Surfaces

ABSTRACTAdhesion of bacteria occurs on virtually all natural and synthetic surfaces and is crucial for their survival. Once they are adhering, bacteria start growing and form a biofilm, in which they are protected against environmental attacks. Bacterial adhesion to surfaces is mediated by a combination of different short- and long-range forces. Here we present a new atomic force microscopy (AFM)-based method to derive long-range bacterial adhesion forces from the dependence of bacterial adhesion forces on the loading force, as applied during the use of AFM. The long-range adhesion forces of wild-typeStaphylococcus aureusparent strains (0.5 and 0.8 nN) amounted to only one-third of these forces measured for their more deformable isogenic Δpbp4mutants that were deficient in peptidoglycan cross-linking. The measured long-range Lifshitz-Van der Waals adhesion forces matched those calculated from published Hamaker constants, provided that a 40% ellipsoidal deformation of the bacterial cell wall was assumed for the Δpbp4mutants. Direct imaging of adhering staphylococci using the AFM peak force-quantitative nanomechanical property mapping imaging mode confirmed a height reduction due to deformation in the Δpbp4mutants of 100 to 200 nm. Across naturally occurring bacterial strains, long-range forces do not vary to the extent observed here for the Δpbp4mutants. Importantly, however, extrapolating from the results of this study, it can be concluded that long-range bacterial adhesion forces are determined not only by the composition and structure of the bacterial cell surface but also by a hitherto neglected, small deformation of the bacterial cell wall, facilitating an increase in contact area and, therewith, in adhesion force.

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A Secreted NlpC/P60 Endopeptidase from Photobacterium damselae subsp. piscicida Cleaves the Peptidoglycan of Potentially Competing Bacteria

mSphere ◽

10.1128/msphere.00736-20 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Johnny Lisboa ◽

Cassilda Pereira ◽

Aline Rifflet ◽

Juan Ayala ◽

Mateus S. Terceti ◽

...

Keyword(s):

Cell Wall ◽

Marine Fish ◽

High Mortality ◽

Bacterial Cell ◽

Structural Integrity ◽

Cell Envelope ◽

Bacterial Cell Wall ◽

Gram Negative ◽

Content Type ◽

Photobacterium Damselae

ABSTRACT Peptidoglycan (PG) is a major component of the bacterial cell wall, forming a mesh-like structure enwrapping the bacteria that is essential for maintaining structural integrity and providing support for anchoring other components of the cell envelope. PG biogenesis is highly dynamic and requires multiple enzymes, including several hydrolases that cleave glycosidic or amide bonds in the PG. This work describes the structural and functional characterization of an NlpC/P60-containing peptidase from Photobacterium damselae subsp. piscicida (Phdp), a Gram-negative bacterium that causes high mortality of warm-water marine fish with great impact for the aquaculture industry. PnpA (Photobacterium NlpC-like protein A) has a four-domain structure with a hydrophobic and narrow access to the catalytic center and specificity for the γ-d-glutamyl-meso-diaminopimelic acid bond. However, PnpA does not cleave the PG of Phdp or PG of several Gram-negative and Gram-positive bacterial species. Interestingly, it is secreted by the Phdp type II secretion system and degrades the PG of Vibrio anguillarum and Vibrio vulnificus. This suggests that PnpA is used by Phdp to gain an advantage over bacteria that compete for the same resources or to obtain nutrients in nutrient-scarce environments. Comparison of the muropeptide composition of PG susceptible and resistant to the catalytic activity of PnpA showed that the global content of muropeptides is similar, suggesting that susceptibility to PnpA is determined by the three-dimensional organization of the muropeptides in the PG. IMPORTANCE Peptidoglycan (PG) is a major component of the bacterial cell wall formed by long chains of two alternating sugars interconnected by short peptides, generating a mesh-like structure that enwraps the bacterial cell. Although PG provides structural integrity and support for anchoring other components of the cell envelope, it is constantly being remodeled through the action of specific enzymes that cleave or join its components. Here, it is shown that Photobacterium damselae subsp. piscicida, a bacterium that causes high mortality in warm-water marine fish, produces PnpA, an enzyme that is secreted into the environment and is able to cleave the PG of potentially competing bacteria, either to gain a competitive advantage and/or to obtain nutrients. The specificity of PnpA for the PG of some bacteria and its inability to cleave others may be explained by differences in the structure of the PG mesh and not by different muropeptide composition.

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Lectin Microarray Reveals Binding Profiles of Lactobacillus casei Strains in a Comprehensive Analysis of Bacterial Cell Wall Polysaccharides

Applied and Environmental Microbiology ◽

10.1128/aem.00240-11 ◽

2011 ◽

Vol 77 (13) ◽

pp. 4539-4546 ◽

Cited By ~ 26

Author(s):

Emi Yasuda ◽

Hiroaki Tateno ◽

Jun Hirabarashi ◽

Tohru Iino ◽

Tomoyuki Sako

Keyword(s):

Cell Wall ◽

Cell Surface ◽

Bacterial Cell ◽

Lactobacillus Casei ◽

Lectin Binding ◽

Bacterial Strains ◽

Cell Wall Polysaccharides ◽

Content Type ◽

Lectin Microarray ◽

Bacterial Cell Surface

ABSTRACTWe previously showed a pivotal role of the polysaccharide (PS) moiety in the cell wall of theLactobacillus caseistrain Shirota (YIT 9029) as a possible immune modulator (E. Yasuda M. Serata, and T. Sako, Appl. Environ. Microbiol. 74:4746-4755, 2008). To distinguish PS structures on the bacterial cell surface of individual strains in relation to their activities, it would be useful to have a rapid and high-throughput methodology. Recently, a new technique called lectin microarray was developed for rapid profiling of glycosylation in eukaryotic polymers and cell surfaces. Here, we report on the development of a simple and sensitive method based on this technology for direct analysis of intact bacterial cell surface glycomes. The method involves labeling bacterial cells with SYTOX Orange before incubation with the lectin microarray. After washing, bound cells are directly detected using an evanescent-field fluorescence scanner in a liquid phase. Using this method, we compared the cell surface glycomes from 16 different strains ofL. casei. The patterns of lectin-binding affinity of most strains were found to be unique. There appears to be two types of lectin-binding profiles: the first is characterized by a few lectins, and the other is characterized by multiple lectins with different specificities. We also showed a dramatic change in the lectin-binding profile of a YIT 9029 derivative with a mutation in thecps1Cgene, encoding a putative glycosyltransferase. In conclusion, the developed technique provided a novel strategy for rapid profiling and, more importantly, differentiating numerous bacterial strains with relevance to the biological functions of PS.

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Measuring the Adhesion Forces for the Multivalent Binding of Vancomycin-Conjugated Dendrimer to Bacterial Cell-Wall Peptide

Langmuir ◽

10.1021/acs.langmuir.8b01137 ◽

2018 ◽

Vol 34 (24) ◽

pp. 7135-7146 ◽

Cited By ~ 4

Author(s):

Elizabeth Peterson ◽

Christine Joseph ◽

Hannah Peterson ◽

Rachael Bouwman ◽

Shengzhuang Tang ◽

...

Keyword(s):

Cell Wall ◽

Bacterial Cell ◽

Bacterial Cell Wall ◽

Adhesion Forces ◽

Multivalent Binding

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EssH Peptidoglycan Hydrolase EnablesStaphylococcus aureusType VII Secretion across the Bacterial Cell Wall Envelope

Journal of Bacteriology ◽

10.1128/jb.00268-18 ◽

2018 ◽

Vol 200 (20) ◽

Cited By ~ 5

Author(s):

Maksym Bobrovskyy ◽

Stephanie E. Willing ◽

Olaf Schneewind ◽

Dominique Missiakas

Keyword(s):

Staphylococcus Aureus ◽

Cell Wall ◽

Bacterial Cell ◽

Bacterial Cell Wall ◽

Hydrolase Activity ◽

Amide Bond ◽

Peptidoglycan Hydrolase ◽

Bacterial Membrane ◽

Secretion Systems ◽

Content Type

ABSTRACTThe ESAT-6-like secretion system (ESS) ofStaphylococcus aureusis assembled in the bacterial membrane from core components that promote the secretion of WXG-like proteins (EsxA, EsxB, EsxC, and EsxD) and the EssD effector. Genes encoding the ESS secretion machinery components, effector, and WXG-like proteins are located in theesslocus. Here, we identifyessH, a heretofore uncharacterized gene of theesslocus, whose product is secreted via an N-terminal signal peptide into the extracellular medium of staphylococcal cultures. EssH exhibits two peptidoglycan hydrolase activities, cleaving the pentaglycine cross bridge and the amide bond ofN-acetylmuramyl-l-alanine, thereby separating glycan chains and wall peptides with cleaved cross bridges. Unlike other peptidoglycan hydrolases, EssH does not promote the lysis of staphylococci. EssH residues Cys199and His254, which are conserved in other CHAP domain enzymes, are required for peptidoglycan hydrolase activity and forS. aureusESS secretion. These data suggest that EssH and its murein hydrolase activity are required for protein secretion by the ESS pathway.IMPORTANCEGene clusters encoding WXG-like proteins and FtsK/SpoIIIE-like P loop ATPases inFirmicutesencode type 7b secretion systems (T7bSS) for the transport of select protein substrates. TheStaphylococcus aureusT7bSS assembles in the bacterial membrane and promotes the secretion of WXG-like proteins and effectors. The mechanisms whereby staphylococci extend the T7SS across the bacterial cell wall envelope are not known. Here, we show that staphylococci secrete EssH to cleave their peptidoglycan, thereby enabling T7bSS transport of proteins across the bacterial cell wall envelope.

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Influence of Adhesion Force onicaAandcidAGene Expression and Production of Matrix Components in Staphylococcus aureus Biofilms

Applied and Environmental Microbiology ◽

10.1128/aem.04178-14 ◽

2015 ◽

Vol 81 (10) ◽

pp. 3369-3378 ◽

Cited By ~ 35

Author(s):

Akshay K. Harapanahalli ◽

Yun Chen ◽

Jiuyi Li ◽

Henk J. Busscher ◽

Henny C. van der Mei

Keyword(s):

Gene Expression ◽

Staphylococcus Aureus ◽

Cell Wall ◽

Adhesion Force ◽

Extracellular Dna ◽

Cross Linking ◽

Adhesion Forces ◽

Content Type ◽

Isogenic Mutant ◽

Matrix Components

ABSTRACTThe majority of human infections are caused by biofilms. The biofilm mode of growth enhances the pathogenicity ofStaphylococcusspp. considerably, because once they adhere, staphylococci embed themselves in a protective, self-produced matrix of extracellular polymeric substances (EPSs). The aim of this study was to investigate the influence of forces of staphylococcal adhesion to different biomaterials onicaA(which regulates the production of EPS matrix components) andcidA(which is associated with cell lysis and extracellular DNA [eDNA] release) gene expression inStaphylococcus aureusbiofilms. Experiments were performed withS. aureusATCC 12600 and its isogenic mutant,S. aureusATCC 12600 Δpbp4, deficient in peptidoglycan cross-linking. Deletion ofpbp4was associated with greater cell wall deformability, while it did not affect the planktonic growth rate, biofilm formation, cell surface hydrophobicity, or zeta potential of the strains. The adhesion forces ofS. aureusATCC 12600 were the strongest on polyethylene (4.9 ± 0.5 nN), intermediate on polymethylmethacrylate (3.1 ± 0.7 nN), and the weakest on stainless steel (1.3 ± 0.2 nN). The production of poly-N-acetylglucosamine, eDNA presence, and expression oficaAgenes decreased with increasing adhesion forces. However, no relation between adhesion forces andcidAexpression was observed. The adhesion forces of the isogenic mutantS. aureusATCC 12600 Δpbp4(deficient in peptidoglycan cross-linking) were much weaker than those of the parent strain and did not show any correlation with the production of poly-N-acetylglucosamine, eDNA presence, or expression of theicaAandcidAgenes. This suggests that adhesion forces modulate the production of the matrix molecule poly-N-acetylglucosamine, eDNA presence, andicaAgene expression by inducing nanoscale cell wall deformation, with cross-linked peptidoglycan layers playing a pivotal role in this adhesion force sensing.

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