scholarly journals Inactivation of the Monofunctional Peptidoglycan Glycosyltransferase SgtB AllowsStaphylococcus aureusTo Survive in the Absence of Lipoteichoic Acid

2018 ◽  
Vol 201 (1) ◽  
Author(s):  
Eleni Karinou ◽  
Christopher F. Schuster ◽  
Manuel Pazos ◽  
Waldemar Vollmer ◽  
Angelika Gründling
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Mutant Strain ◽  
Teichoic Acid ◽  
Fold Increase ◽  
Lipoteichoic Acid ◽  
Wall Teichoic Acid ◽  
Content Type ◽  
Anionic Polymers ◽  
Peptidoglycan Structure

ABSTRACTThe cell wall ofStaphylococcus aureusis composed of peptidoglycan and the anionic polymers lipoteichoic acid (LTA) and wall teichoic acid. LTA is required for growth and normal cell morphology inS. aureus. Strains lacking LTA are usually viable only when grown under osmotically stabilizing conditions or after the acquisition of compensatory mutations. LTA-negative suppressor strains with inactivating mutations ingdpP, which resulted in increased intracellular c-di-AMP levels, were described previously. Here, we sought to identify factors other than c-di-AMP that allowS. aureusto survive without LTA. LTA-negative strains able to grow in unsupplemented medium were obtained and found to contain mutations insgtB,mazE,clpX, orvraT. The growth improvement through mutations inmazEandsgtBwas confirmed by complementation analysis. We also showed that anS. aureussgtBtransposon mutant, with the monofunctional peptidoglycan glycosyltransferase SgtB inactivated, displayed a 4-fold increase in the MIC of oxacillin, suggesting that alterations in the peptidoglycan structure could help bacteria compensate for the lack of LTA. Muropeptide analysis of peptidoglycans isolated from a wild-type strain andsgtBmutant strain did not reveal any sizable alterations in the peptidoglycan structure. In contrast, the peptidoglycan isolated from an LTA-negativeltaSmutant strain showed a significant reduction in the fraction of highly cross-linked peptidoglycan, which was partially rescued in thesgtB ltaSdouble mutant suppressor strain. Taken together, these data point toward an important function of LTA in cell wall integrity through its necessity for proper peptidoglycan assembly.IMPORTANCEThe bacterial cell wall acts as a primary defense against environmental insults such as changes in osmolarity. It is also a vulnerable structure, as defects in its synthesis can lead to growth arrest or cell death. The important human pathogenStaphylococcus aureushas a typical Gram-positive cell wall, which consists of peptidoglycan and the anionic polymers LTA and wall teichoic acid. Several clinically relevant antibiotics inhibit the synthesis of peptidoglycan; therefore, it and teichoic acids are considered attractive targets for the development of new antimicrobials. We show that LTA is required for efficient peptidoglycan cross-linking inS. aureusand inactivation of a peptidoglycan glycosyltransferase can partially rescue this defect, together revealing an intimate link between peptidoglycan and LTA synthesis.

scholarly journals Inactivation of the monofunctional peptidoglycan glycosyltransferase SgtB allowsStaphylococcus aureusto survive in the absence of lipoteichoic acid

2018 ◽  
Author(s):  
Eleni Karinou ◽  
Christopher F. Schuster ◽  
Manuel Pazos ◽  
Waldemar Vollmer ◽  
Angelika Gründling
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Teichoic Acid ◽  
Fold Increase ◽  
Lipoteichoic Acid ◽  
Wall Teichoic Acid ◽  
Anionic Polymers ◽  
Peptidoglycan Structure ◽  
Intimate Link ◽  
Inactivating Mutations

AbstractThe cell wall ofStaphylococcus aureusis composed of peptidoglycan and the anionic polymers lipoteichoic acid (LTA) and wall teichoic acid. LTA is required for growth and normal cell morphology inS. aureus.Strains lacking LTA are usually only viable when grown under osmotically stabilizing conditions or after the acquisition of compensatory mutations. LTA negative suppressor strains with inactivating mutations ingdpP, resulting in an increase in intracellular c-di-AMP levels, have been described previously. Here, we sought to identify factors other than c-di-AMP that allowS. aureusto survive without LTA. LTA-negative strains able to grow in un-supplemented medium were obtained and found to contain mutations insgtB, mazE, clpXorvraT. The growth improvement through mutations inmazEandsgtBwas confirmed by complementation analysis. We also show that anS. aureus sgtBtransposon mutant, inactivated for the monofunctional peptidoglycan glycosyltransferase SgtB, displays a 4-fold increase in the MIC towards a number of cell wall-targeting antibiotics, suggesting that alteration in the peptidoglycan structure could help bacteria compensate for the lack of LTA. Muropeptide analysis of peptidoglycan isolated from a WT andsgtBmutant strains did not reveal any sizable alternations in the peptidoglycan structure. In contrast, the peptidoglycan isolated from an LTA-negativeltaSmutant strain showed a significant reduction in the fraction of highly crosslinked peptidoglycan, which was partially rescued in thesgtB/ltaSdouble mutant suppressor strain. Taken together, these data point towards an important function of LTA in cell wall integrity through its requirement for proper peptidoglycan assembly.ImportanceThe bacterial cell wall acts as primary defence against environmental insults such as changes in osmolarity. It is also a vulnerable structure as defects in its synthesis can lead to growth arrest or cell death. The important human pathogenStaphylococcus aureushas a typical Gram-positive cell wall, which consists of peptidoglycan and the anionic polymers lipoteichoic acid (LTA) and wall teichoic acid. Several clinically relevant antibiotics inhibit the synthesis of peptidoglycan; hence it and teichoic acids are considered attractive targets for the development of new antimicrobials. We show that LTA is required for efficient peptidoglycan crosslinking inS. aureusand inactivation of a peptidoglycan glycosyltransferase can partially rescue this defect, altogether revealing an intimate link between peptidoglycan and LTA synthesis.

scholarly journals Cross-Linked Peptidoglycan Mediates Lysostaphin Binding to the Cell Wall Envelope of Staphylococcus aureus

2006 ◽  
Vol 188 (7) ◽  
pp. 2463-2472 ◽  
Author(s):  
Angelika Gründling ◽  
Olaf Schneewind
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Fluorescent Protein ◽  
Teichoic Acid ◽  
Lipoteichoic Acid ◽  
Wall Teichoic Acid ◽  
Cross Bridges ◽  
Specific Association ◽  
Species Specific ◽  
Green Fluorescent

ABSTRACT Staphylococcus simulans bv. staphylolyticus secretes lysostaphin, a bacteriocin that cleaves pentaglycine cross bridges in the cell wall of Staphylococcus aureus. The C-terminal cell wall-targeting domain (CWT) of lysostaphin is required for selective binding of this bacteriocin to S. aureus cells; however, the molecular target for this was unknown. We used purified green fluorescent protein fused to CWT (GFP-CWT) to reveal species-specific association of the reporter with staphylococci. GFP-CWT bound S. aureus cells as well as purified peptidoglycan sacculi. The addition of cross-linked murein, disaccharides linked to interconnected wall peptides, blocked GFP-CWT binding to staphylococci, whereas murein monomers or lysostaphin-solubilized cell wall fragments did not. S. aureus strain Newman variants lacking the capacity for synthesizing polysaccharide capsule (capFO), poly-N-acetylglucosamine (icaAC), lipoprotein (lgt), cell wall-anchored proteins (srtA), or the glycolipid anchor of lipoteichoic acid (ypfP) bound GFP-CWT similar to wild-type staphylococci. A tagO mutant strain, defective in the synthesis of polyribitol wall teichoic acid attached to the cell wall envelope, displayed increased GFP-CWT binding. In contrast, a femAB mutation, reducing both the amount and the length of peptidoglycan cross-linking (monoglycine cross bridges), showed a dramatic reduction in GFP-CWT binding. Thus, the CWT domain of lysostaphin directs the bacteriocin to cross-linked peptidoglycan, which also serves as the substrate for its glycyl-glycine endopeptidase domain.

scholarly journals An Antibiotic That Inhibits a Late Step in Wall Teichoic Acid Biosynthesis Induces the Cell Wall Stress Stimulon in Staphylococcus aureus

2012 ◽  
Vol 56 (4) ◽  
pp. 1810-1820 ◽  
Author(s):  
Jennifer Campbell ◽  
Atul K. Singh ◽  
Jonathan G. Swoboda ◽  
Michael S. Gilmore ◽  
Brian J. Wilkinson ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Osmotic Stress ◽  
Late Stage ◽  
Teichoic Acid ◽  
Wall Stress ◽  
Wall Teichoic Acid ◽  
Content Type ◽  
Cell Wall Stress

ABSTRACTWall teichoic acids (WTAs) are phosphate-rich, sugar-based polymers attached to the cell walls of most Gram-positive bacteria. InStaphylococcus aureus, these anionic polymers regulate cell division, protect cells from osmotic stress, mediate host colonization, and mask enzymatically susceptible peptidoglycan bonds. Although WTAs are not required for survivalin vitro, blocking the pathway at a late stage of synthesis is lethal. We recently discovered a novel antibiotic, targocil, that inhibits a late acting step in the WTA pathway. Its target is TarG, the transmembrane component of the ABC transporter (TarGH) that exports WTAs to the cell surface. We examined here the effects of targocil onS. aureususing transmission electron microscopy and gene expression profiling. We report that targocil treatment leads to multicellular clusters containing swollen cells displaying evidence of osmotic stress, strongly induces the cell wall stress stimulon, and reduces the expression of key virulence genes, includingdltABCDand capsule genes. We conclude that WTA inhibitors that act at a late stage of the biosynthetic pathway may be useful as antibiotics, and we present evidence that they could be particularly useful in combination with beta-lactams.

scholarly journals Teichoic Acid Polymers Affect Expression and Localization of dl-Endopeptidase LytE Required for Lateral Cell Wall Hydrolysis in Bacillus subtilis

2016 ◽  
Vol 198 (11) ◽  
pp. 1585-1594 ◽  
Author(s):  
Jun Kasahara ◽  
Yuuka Kiriyama ◽  
Mari Miyashita ◽  
Takuma Kondo ◽  
Takeshi Yamada ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
High Temperatures ◽  
Teichoic Acid ◽  
Lipoteichoic Acid ◽  
Peptidoglycan Hydrolase ◽  
Wall Teichoic Acid ◽  
Anionic Polymers ◽  
Peptidoglycan Hydrolysis ◽  
Lateral Cell

ABSTRACTInBacillus subtilis, thedl-endopeptidase LytE is responsible for lateral peptidoglycan hydrolysis during cell elongation. We found that σI-dependent transcription oflytEis considerably enhanced in a strain with a mutation inltaS, which encodes a major lipoteichoic acid (LTA) synthase. Similar enhancements were observed in mutants that affect the glycolipid anchor and wall teichoic acid (WTA) synthetic pathways. Immunofluorescence microscopy revealed that the LytE foci were considerably increased in these mutants. The localization patterns of LytE on the sidewalls appeared to be helix-like in LTA-defective or WTA-reduced cells and evenly distributed on WTA-depleted or -defective cell surfaces. These results strongly suggested that LTA and WTA affect both σI-dependent expression and localization of LytE. Interestingly, increased LytE localization along the sidewall in theltaSmutant largely occurred in an MreBH-independent manner. Moreover, we found that cell surface decorations with LTA and WTA are gradually reduced at increased culture temperatures and that LTA rather than WTA on the cell surface is reduced at high temperatures. In contrast, the amount of LytE on the cell surface gradually increased under heat stress conditions. Taken together, these results indicated that reductions in these anionic polymers at high temperatures might give rise to increases in SigI-dependent expression and cell surface localization of LytE at high temperatures.IMPORTANCEThe bacterial cell wall is required for maintaining cell shape and bearing environmental stresses. The Gram-positive cell wall consists of mesh-like peptidoglycan and covalently linked wall teichoic acid and lipoteichoic acid polymers. It is important to determine if these anionic polymers are required for proliferation and environmental adaptation. Here, we demonstrated that these polymers affect the expression and localization of a peptidoglycan hydrolase LytE required for lateral cell wall elongation. Moreover, we found that cell surface decorations with teichoic acid polymers are substantially decreased at high temperatures and that the peptidoglycan hydrolase is consequently increased. These findings suggest that teichoic acid polymers control lateral peptidoglycan hydrolysis by LytE, and bacteria drastically change their cell wall content to adapt to their environment.

scholarly journals Glycosylation of Staphylococcus aureus cell wall teichoic acid is influenced by environmental conditions

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Noëlle Mistretta ◽  
Marina Brossaud ◽  
Fabienne Telles ◽  
Violette Sanchez ◽  
Philippe Talaga ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Environmental Conditions ◽  
Teichoic Acid ◽  
Wall Teichoic Acid

scholarly journals LytR-CpsA-Psr Enzymes as Determinants of Bacillus anthracis Secondary Cell Wall Polysaccharide Assembly

2014 ◽  
Vol 197 (2) ◽  
pp. 343-353 ◽  
Author(s):  
Megan Liszewski Zilla ◽  
Yvonne G. Y. Chan ◽  
Justin Mark Lunderberg ◽  
Olaf Schneewind ◽  
Dominique Missiakas
Keyword(s):  
Cell Wall ◽  
Bacillus Anthracis ◽  
Chain Length ◽  
Secondary Cell Wall ◽  
Teichoic Acid ◽  
Cell Wall Polysaccharide ◽  
Wall Teichoic Acid ◽  
Content Type ◽  
Associated Proteins ◽  
Layer Assembly

Bacillus anthracis, the causative agent of anthrax, replicates as chains of vegetative cells by regulating the separation of septal peptidoglycan. Surface (S)-layer proteins and associated proteins (BSLs) function as chain length determinants and bind to the secondary cell wall polysaccharide (SCWP). In this study, we identified theB. anthracislcpDmutant, which displays increased chain length and S-layer assembly defects due to diminished SCWP attachment to peptidoglycan. In contrast, theB. anthracislcpB3variant displayed reduced cell size and chain length, which could be attributed to increased deposition of BSLs. In other bacteria, LytR-CpsA-Psr (LCP) proteins attach wall teichoic acid (WTA) and polysaccharide capsule to peptidoglycan.B. anthracisdoes not synthesize these polymers, yet its genome encodes six LCP homologues, which, when expressed inS. aureus, promote WTA attachment. We propose a model wherebyB. anthracisLCPs promote attachment of SCWP precursors to discrete locations in the peptidoglycan, enabling BSL assembly and regulated separation of septal peptidoglycan.

scholarly journals Role of the msaABCR Operon in Cell Wall Biosynthesis, Autolysis, Integrity, and Antibiotic Resistance in Staphylococcus aureus

2019 ◽  
Vol 63 (10) ◽  
Author(s):  
Bibek G C ◽  
Gyan S. Sahukhal ◽  
Mohamed O. Elasri
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Antibiotic Resistance ◽  
Teichoic Acid ◽  
Cross Linking ◽  
Wall Defect ◽  
Content Type ◽  
Mrsa Strains ◽  
Mutant Cells

ABSTRACT Staphylococcus aureus is an important human pathogen in both community and health care settings. One of the challenges with S. aureus as a pathogen is its acquisition of antibiotic resistance. Previously, we showed that deletion of the msaABCR operon reduces cell wall thickness, resulting in decreased resistance to vancomycin in vancomycin-intermediate S. aureus (VISA). In this study, we investigated the nature of the cell wall defect in the msaABCR operon mutant in the Mu50 (VISA) and USA300 LAC methicillin-resistant Staphylococcus aureus (MRSA) strains. Results showed that msaABCR mutant cells had decreased cross-linking in both strains. This defect is typically due to increased murein hydrolase activity and/or nonspecific processing of murein hydrolases mediated by increased protease activity in mutant cells. The defect was enhanced by a decrease in teichoic acid content in the msaABCR mutant. Therefore, we propose that deletion of the msaABCR operon results in decreased peptidoglycan cross-linking, leading to increased susceptibility toward cell wall-targeting antibiotics, such as β-lactams and vancomycin. Moreover, we also observed significantly downregulated transcription of early cell wall-synthesizing genes, supporting the finding that msaABCR mutant cells have decreased peptidoglycan synthesis. More specifically, the msaABCR mutant in the USA300 LAC strain (MRSA) showed significantly reduced expression of the murA gene, whereas the msaABCR mutant in the Mu50 strain (VISA) showed significantly reduced expression of glmU, murA, and murD. Thus, we conclude that the msaABCR operon controls the balance between cell wall synthesis and cell wall hydrolysis, which is required for maintaining a robust cell wall and acquiring resistance to cell wall-targeting antibiotics, such as vancomycin and the β-lactams.

scholarly journals Surface Glycopolymers Are Crucial forIn VitroAnti-Wall Teichoic Acid IgG-Mediated Complement Activation and Opsonophagocytosis of Staphylococcus aureus

2015 ◽  
Vol 83 (11) ◽  
pp. 4247-4255 ◽  
Author(s):  
Jong-Ho Lee ◽  
Na-Hyang Kim ◽  
Volker Winstel ◽  
Kenji Kurokawa ◽  
Jesper Larsen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Teichoic Acid ◽  
Complement C3 ◽  
Glycerol Phosphate ◽  
Glycosylation Pattern ◽  
Wall Teichoic Acid ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Capsule Production ◽  
Cell Envelopes

ABSTRACTThe cell envelopes of many Gram-positive bacteria contain wall teichoic acids (WTAs).Staphylococcus aureusWTAs are composed of ribitol phosphate (RboP) or glycerol phosphate (GroP) backbones substituted withd-alanine andN-acetyl-d-glucosamine (GlcNAc) orN-acetyl-d-galactosamine (GalNAc). Two WTA glycosyltransferases, TarM and TarS, are responsible for modifying the RboP WTA with α-GlcNAc and β-GlcNAc, respectively. We recently reported that purified human serum anti-WTA IgG specifically recognizes β-GlcNAc of the staphylococcal RboP WTA and then facilitates complement C3 deposition and opsonophagocytosis ofS. aureuslaboratory strains. This prompted us to examine whether anti-WTA IgG can induce C3 deposition on a diverse set of clinicalS. aureusisolates. To this end, we compared anti-WTA IgG-mediated C3 deposition and opsonophagocytosis abilities using 13 different staphylococcal strains. Of note, the majority ofS. aureusstrains tested was recognized by anti-WTA IgG, resulting in C3 deposition and opsonophagocytosis. A minority of strains was not recognized by anti-WTA IgG, which correlated with either extensive capsule production or an alteration in the WTA glycosylation pattern. Our results demonstrate that the presence of WTAs with TarS-mediated glycosylation with β-GlcNAc in clinically isolatedS. aureusstrains is an important factor for induction of anti-WTA IgG-mediated C3 deposition and opsonophagocytosis.

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