scholarly journals Correlation of Daptomycin Resistance in a ClinicalStaphylococcus aureusStrain with Increased Cell Wall Teichoic Acid Production and d-Alanylation

2011 ◽  
Vol 55 (8) ◽  
pp. 3922-3928 ◽  
Author(s):  
Ute Bertsche ◽  
Christopher Weidenmaier ◽  
Daniel Kuehner ◽  
Soo-Jin Yang ◽  
Stefanie Baur ◽  
...  
Keyword(s):  
Cell Wall ◽  
Parental Strain ◽  
Teichoic Acid ◽  
Side Chain ◽  
Wall Thickening ◽  
Wall Teichoic Acid ◽  
Transmission Electron ◽  
Dry Cell Weight ◽  
Cross Linkage ◽  
Resistant Strains

ABSTRACTCell wall thickening is a common feature among daptomycin-resistantStaphylococcus aureusstrains. However, the mechanism(s) leading to this phenotype is unknown. We examined a number of cell wall synthesis pathway parameters in an isogenic strain set ofS. aureusbloodstream isolates obtained from a patient with recalcitrant endocarditis who failed daptomycin therapy, including the initial daptomycin-susceptible parental strain (strain 616) and two daptomycin-resistant strains (strains 701 and 703) isolated during daptomycin therapy. Transmission electron microscopy demonstrated significantly thicker cell walls in the daptomycin-resistant strains than in the daptomycin-susceptible strain, a finding which was compatible with significant differences in dry cell weight of strain 616 versus strains 701 to 703 (P< 0.05). Results of detailed analysis of cell wall muropeptide composition, the degree of peptide side chain cross-linkage, and the amount of the peptidoglycan precursor, UDP-MurNAc-pentapeptide, were similar in the daptomycin-susceptible and daptomycin-resistant isolates. In contrast, the daptomycin-resistant strains contained less O-acetylated peptidoglycan. Importantly, both daptomycin-resistant strains synthesized significantly more wall teichoic acid (WTA) than the parental strain (P< 0.001). Moreover, the proportion ofd-alanylated WTA species was substantially higher in the daptomycin-resistant strains than in the daptomycin-susceptible parental strain (P< 0.05 in comparing strain 616 versus strain 701). The latter phenotypic findings correlated with (i) enhancedtagAanddltAgene expression, respectively, and (ii) an increase in surface positive charge observed in the daptomycin-resistant versus daptomycin-susceptible isolates. Collectively, these data suggest that increases in WTA synthesis and the degree of itsd-alanylation may play a major role in the daptomycin-resistant phenotype in someS. aureusstrains.

scholarly journals Wall Teichoic Acid Deficiency in Staphylococcus aureus Confers Selective Resistance to Mammalian Group IIA Phospholipase A2 and Human β-Defensin 3

2008 ◽  
Vol 76 (5) ◽  
pp. 2169-2176 ◽  
Author(s):  
Tomaz Koprivnjak ◽  
Christopher Weidenmaier ◽  
Andreas Peschel ◽  
Jerrold P. Weiss
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Electrostatic Interactions ◽  
Bacterial Resistance ◽  
Teichoic Acid ◽  
Host Cells ◽  
Wall Teichoic Acid ◽  
Transmission Electron ◽  
Magainin Ii ◽  
Wall Teichoic Acids

ABSTRACT Wall teichoic acids (WTAs) and membrane lipoteichoic acids (LTAs) are the major polyanionic polymers in the envelope of Staphylococcus aureus. WTAs in S. aureus play an important role in bacteriophage attachment and bacterial adherence to certain host cells, suggesting that WTAs are exposed on the cell surface and could also provide necessary binding sites for cationic antimicrobial peptides and proteins (CAMPs). Highly cationic mammalian group IIA phospholipase A2 (gIIA PLA2) kills S. aureus at nanomolar concentrations by an action(s) that depends on initial electrostatic interactions, cell wall penetration, membrane phospholipid (PL) degradation, and activation of autolysins. A tagO mutant of S. aureus that lacks WTA is up to 100-fold more resistant to PL degradation and killing by gIIA PLA2 and CAMP human β-defensin 3 (HBD-3) but has the sensitivity of the wild type (wt) to other CAMPs, such as Magainin II amide, hNP1-3, LL-37, and lactoferrin. In contrast, there is little or no difference in either gIIA PLA2 activity toward cell wall-depleted protoplasts of the wt and tagO strains of S. aureus or in binding of gIIA PLA2 to wt and tagO strains. Scanning and transmission electron microscopy reveal increased surface protrusions in the S. aureus tagO mutant that might account for reduced activity of bound gIIA PLA2 and HBD-3 toward the tagO mutant. In summary, the absence of WTA in S. aureus causes a selective increase in bacterial resistance to gIIA PLA2 and HBD-3, the former apparently by reducing access and/or activity of bound antibacterial enzyme to the bacterial membrane.

scholarly journals Synergism Effect of the Essential Oil fromOcimum basilicumvar. Maria Bonita and Its Major Components with Fluconazole and Its Influence on Ergosterol Biosynthesis

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Nathalia N. R. Cardoso ◽  
Celuta S. Alviano ◽  
Arie F. Blank ◽  
Maria Teresa V. Romanos ◽  
Beatriz B. Fonseca ◽  
...  
Keyword(s):  
Cell Wall ◽  
Ergosterol Biosynthesis ◽  
Wall Thickening ◽  
Potential Source ◽  
Transmission Electron ◽  
Genetically Improved ◽  
Resistant Strains ◽  
Subinhibitory Concentrations ◽  
Capsule Size ◽  
Synergism Effect

The aim of this study was to evaluate the activity of the EO and its major components ofOcimum basilicumvar. Maria Bonita, a genetically improved cultivar, against the fluconazole sensitive and resistant strains ofCandida albicansandCryptococcus neoformans. Geraniol presented better results than the EO, with a low MIC (76 μg/mL againstC. neoformansand 152 μg/mL against bothCandidastrains). The combination of EO, linalool, or geraniol with fluconazole enhanced their antifungal activity, especially against the resistant strain (MIC reduced to 156, 197, and 38 μg/mL, resp.). The ergosterol assay showed that subinhibitory concentrations of the substances were able to reduce the amount of sterol extracted. The substances tested were able to reduce the capsule size which suggests they have an important mechanism of action. Transmission electron microscopy demonstrated cell wall destruction ofC. neoformansafter treatment with subinhibitory concentrations. InC. albicansultrastructure alterations such as irregularities in the membrane, presence of vesicles, and cell wall thickening were observed. The biofilm formation was inhibited in bothC. albicansstrains at MIC and twice MIC. These results provide further support for the use ofO. basilicumEO and its major components as a potential source of antifungal agents.

scholarly journals Alterations of Cell Wall Structure and MetabolismAccompany Reduced Susceptibility to Vancomycin in an IsogenicSeries of Clinical Isolates of Staphylococcusaureus

2003 ◽  
Vol 185 (24) ◽  
pp. 7103-7110 ◽  
Author(s):  
K. Sieradzki ◽  
A. Tomasz
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Teichoic Acid ◽  
Qualitative Change ◽  
Resistant Cell ◽  
Wall Structure ◽  
Wall Teichoic Acid ◽  
In Vitro Hydrolysis ◽  
Cross Linkage

ABSTRACT A series of isogenic methicillin-resistant Staphylococcus aureus isolates recovered from a bacteremic patient were shown to acquire gradually increasing levels of resistance to vancomycin during chemotherapy with the drug (K. Sieradzki, T. Leski, L. Borio, J. Dick, and A. Tomasz, J. Clin. Microbiol. 41:1687-1693, 2003). We compared properties of the earliest (parental) vancomycin-susceptible isolate, JH1 (MIC, 1 μg/ml), to two late (progeny) isolates, JH9 and JH14 (vancomycin MIC, 8 μg/ml). The resistant isolates produced abnormally thick cell walls and poorly separated cells when grown in antibiotic-free medium. Chemical analysis of the resistant isolates showed decreased cross-linkage of the peptidoglycan and drastically reduced levels of PBP4 as determined by the fluorographic assay. Resistant isolates showed reduced rates of cell wall turnover and autolysis. In vitro hydrolysis of resistant cell walls by autolytic extracts prepared from either susceptible or resistant strains was also slow, and this abnormality could be traced to a quantitative (or qualitative) change in the wall teichoic acid component of resistant isolates. Some change in the structure and/or metabolism of teichoic acids appears to be an important component of the mechanism of decreased susceptibility to vancomycin in S. aureus.

scholarly journals Teichoic Acid Is an Essential Polymer in Bacillus subtilis That Is Functionally Distinct from Teichuronic Acid

2004 ◽  
Vol 186 (23) ◽  
pp. 7865-7873 ◽  
Author(s):  
Amit P. Bhavsar ◽  
Laura K. Erdman ◽  
Jeffrey W. Schertzer ◽  
Eric D. Brown
Keyword(s):  
Cell Wall ◽  
Bacillus Subtilis ◽  
Teichoic Acid ◽  
Wall Thickening ◽  
Glycerol Phosphate ◽  
Wall Teichoic Acid ◽  
Teichoic Acids ◽  
Gram Positive Bacteria ◽  
Teichuronic Acid ◽  
Wall Teichoic Acids

ABSTRACT Wall teichoic acids are anionic, phosphate-rich polymers linked to the peptidoglycan of gram-positive bacteria. In Bacillus subtilis, the predominant wall teichoic acid types are poly(glycerol phosphate) in strain 168 and poly(ribitol phosphate) in strain W23, and they are synthesized by the tag and tar gene products, respectively. Growing evidence suggests that wall teichoic acids are essential in B. subtilis; however, it is widely believed that teichoic acids are dispensable under phosphate-limiting conditions. In the work reported here, we carefully studied the dispensability of teichoic acid under phosphate-limiting conditions by constructing three new mutants. These strains, having precise deletions in tagB, tagF, and tarD, were dependent on xylose-inducible complementation from a distal locus (amyE) for growth. The tarD deletion interrupted poly(ribitol phosphate) synthesis in B. subtilis and represents a unique deletion of a tar gene. When teichoic acid biosynthetic proteins were depleted, the mutants showed a coccoid morphology and cell wall thickening. The new wall teichoic acid biogenesis mutants generated in this work and a previously reported tagD mutant were not viable under phosphate-limiting conditions in the absence of complementation. Cell wall analysis of B. subtilis grown under phosphate-limited conditions showed that teichoic acid contributed approximately one-third of the wall anionic content. These data suggest that wall teichoic acid has an essential function in B. subtilis that cannot be replaced by teichuronic acid.

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 Control of teichoic acid and teichuronic acid biosynthesis in chemostat cultures of Bacillus subtilis var. niger

1969 ◽  
Vol 111 (1) ◽  
pp. 1-5 ◽  
Author(s):  
D C Ellwood ◽  
D. W. Tempest
Keyword(s):  
Cell Wall ◽  
Bacillus Subtilis ◽  
Teichoic Acid ◽  
Extracellular Fluid ◽  
Acid Synthesis ◽  
Growth Cycle ◽  
Wall Material ◽  
Wall Teichoic Acid ◽  
Anionic Polymers ◽  
Teichuronic Acid

1. Quantitative determination of the anionic polymers present in the walls of Bacillus subtilis var. niger organisms undergoing transition, in a chemostat culture, from either Mg2+-limitation to PO43−-limitation or K+-limitation to PO43−-limitation showed that teichuronic acid synthesis started immediately the culture became PO43−-limited and proceeded at a rate substantially faster than the rate of biomass synthesis. 2. Simultaneously, the cell-wall teichoic acid content diminished at a rate greater than that due to dilution by newly synthesized wall material, and fragments of teichoic acid and mucopeptide accumulated in the culture extracellular fluid. 3. Equally rapid reverse changes occurred when a PO43−-limited B. subtilis var. niger culture was returned to being Mg2+-limited. 4. It is concluded that in this organism both teichoic acid and teichuronic acid syntheses are expressions of a single genotype, and a mechanism for the control of synthesis of both polymers is suggested. 5. These results are discussed with reference to the constantly changing environmental conditions that obtain in a batch culture and the variation in bacterial cell-wall composition that is reported to occur throughout the growth cycle.

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