Activated ADI pathway: the initiator of intermediate vancomycin resistance inStaphylococcus aureus

2017 ◽  
Vol 63 (3) ◽  
pp. 260-264 ◽  
Author(s):  
Xin-Ee Tan ◽  
Hui-min Neoh ◽  
Mee-Lee Looi ◽  
Siok Fong Chin ◽  
Longzhu Cui ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cell Walls ◽  
Vancomycin Resistance ◽  
Cell Wall Biosynthesis ◽  
Ornithine Carbamoyltransferase ◽  
Proteomic Profiling ◽  
Arginine Catabolism ◽  
By Products ◽  
Catabolism Pathway

Comparative proteomic profiling between 2 vancomycin-intermediate Staphylococcus aureus (VISA) strains, Mu50Ω-vraSm and Mu50Ω-vraSm-graRm, and vancomycin-susceptible S. aureus (VSSA) strain Mu50Ω revealed upregulated levels of catabolic ornithine carbamoyltransferase (ArcB) of the arginine catabolism pathway in VISA strains. Subsequent analyses showed that the VISA strains have higher levels of cellular ATP and ammonia, which are by-products of arginine catabolism, and displayed thicker cell walls. We postulate that elevated cytoplasmic ammonia and ATP molecules, resulting from activated arginine catabolism upon acquisition of vraS and graR mutations, are important requirements facilitating cell wall biosynthesis, thereby contributing to thickened cell wall and consequently reduced vancomycin susceptibility in VISA strains.

scholarly journals Penicillin-Binding Protein 2 Is Essential for Expression of High-Level Vancomycin Resistance and Cell Wall Synthesis in Vancomycin- Resistant Staphylococcus aureus Carrying the Enterococcal vanA Gene Complex

2004 ◽  
Vol 48 (12) ◽  
pp. 4566-4573 ◽  
Author(s):  
Anatoly Severin ◽  
Shang Wei Wu ◽  
Keiko Tabei ◽  
Alexander Tomasz
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Binding Protein ◽  
Inducible Promoter ◽  
Protein Product ◽  
Vancomycin Resistance ◽  
Penicillin Binding Protein ◽  
Oxacillin Resistance ◽  
Vancomycin Resistant ◽  
High Level

ABSTRACT A combination of biochemical and genetic experiments were performed in order to better understand the mechanism of expression of high-level vancomycin resistance in Staphylococcus aureus. The transcription of pbp2 of the highly vancomycin- and oxacillin-resistant strain COLVA200 and its mutant derivative with inactivated mecA were put under the control of an inducible promoter, and the dependence of oxacillin and vancomycin resistance and cell wall composition on the concentration of the isopropyl-β-d-thiogalactopyranoside inducer was determined. The results indicate that mecA—the genetic determinant of oxacillin resistance—while essential for oxacillin resistance, is not involved with the expression of vancomycin resistance. Penicillin binding protein 2A, the protein product of mecA, appears to be unable to utilize the depsipeptide cell wall precursor produced in the vancomycin-resistant cells for transpeptidation. The key penicillin binding protein essential for vancomycin resistance and for the synthesis of the abnormally structured cell walls characteristic of vancomycin-resistant S. aureus (A. Severin, K. Tabei, F. Tenover, M. Chung, N. Clarke, and A. Tomasz, J. Biol. Chem. 279:3398-3407, 2004) is penicillin binding protein 2.

scholarly journals LambdaSa1 and LambdaSa2 Prophage Lysins of Streptococcus agalactiae

2007 ◽  
Vol 73 (22) ◽  
pp. 7150-7154 ◽  
Author(s):  
David G. Pritchard ◽  
Shengli Dong ◽  
Marion C. Kirk ◽  
Robert T. Cartee ◽  
John R. Baker
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Streptococcus Agalactiae ◽  
Synthetic Peptide ◽  
Cell Walls ◽  
Peptide Substrate ◽  
Amidase Activity ◽  
Cleavage Specificity ◽  
Endopeptidase Activity

ABSTRACT Putative N-acetylmuramyl-l-alanine amidase genes from LambdaSa1 and LambdaSa2 prophages of Streptococcus agalactiae were cloned and expressed in Escherichia coli. The purified enzymes lysed the cell walls of Streptococcus agalactiae, Streptococcus pneumoniae, and Staphylococcus aureus. The peptidoglycan digestion products in the cell wall lysates were not consistent with amidase activity. Instead, the structure of the muropeptide digestion fragments indicated that both the LambdaSa1 and LambdaSa2 lysins exhibited γ-d-glutaminyl-l-lysine endopeptidase activity. The endopeptidase cleavage specificity of the lysins was confirmed using a synthetic peptide substrate corresponding to a portion of the stem peptide and cross bridge of Streptococcus agalactiae peptidoglycan. The LambdaSa2 lysin also displayed β-d-N-acetylglucosaminidase activity.

scholarly journals Staphylococcus aureus cell wall structure and dynamics during host-pathogen interaction

2021 ◽  
Vol 17 (3) ◽  
pp. e1009468
Author(s):  
Joshua A. F. Sutton ◽  
Oliver T. Carnell ◽  
Lucia Lafage ◽  
Joe Gray ◽  
Jacob Biboy ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cell Walls ◽  
Ex Vivo ◽  
Cell Wall Structure ◽  
Wall Structure ◽  
Bacterial Cells ◽  
Human Macrophages ◽  
Structure And Dynamics

Peptidoglycan is the major structural component of the Staphylococcus aureus cell wall, in which it maintains cellular integrity, is the interface with the host, and its synthesis is targeted by some of the most crucial antibiotics developed. Despite this importance, and the wealth of data from in vitro studies, we do not understand the structure and dynamics of peptidoglycan during infection. In this study we have developed methods to harvest bacteria from an active infection in order to purify cell walls for biochemical analysis ex vivo. Isolated ex vivo bacterial cells are smaller than those actively growing in vitro, with thickened cell walls and reduced peptidoglycan crosslinking, similar to that of stationary phase cells. These features suggested a role for specific peptidoglycan homeostatic mechanisms in disease. As S. aureus penicillin binding protein 4 (PBP4) has reduced peptidoglycan crosslinking in vitro its role during infection was established. Loss of PBP4 resulted in an increased recovery of S. aureus from the livers of infected mice, which correlated with enhanced fitness within murine and human macrophages. Thicker cell walls correlate with reduced activity of peptidoglycan hydrolases. S. aureus has a family of 4 putative glucosaminidases, that are collectively crucial for growth. Loss of the major enzyme SagB, led to attenuation during murine infection and reduced survival in human macrophages. However, loss of the other three enzymes Atl, SagA and ScaH resulted in clustering dependent attenuation, in a zebrafish embryo, but not a murine, model of infection. A combination of pbp4 and sagB deficiencies resulted in a restoration of parental virulence. Our results, demonstrate the importance of appropriate cell wall structure and dynamics during pathogenesis, providing new insight to the mechanisms of disease.

Antibacterial Mechanism of Long-Chain Polyphosphates in Staphylococcus aureus

1994 ◽  
Vol 57 (4) ◽  
pp. 289-294 ◽  
Author(s):  
RUBY M. LEE ◽  
PAUL A. HARTMAN ◽  
H. MICHAEL STAHR ◽  
DENNIS G. OLSON ◽  
FRED D. WILLIAMS
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cell Walls ◽  
Metal Ion ◽  
Antibacterial Mechanism ◽  
Essential Metals ◽  
Bacterial Leakage ◽  
Metal Ion Chelation ◽  
Free Metal ◽  
Long Chain

The results of previous studies indicated that the antibacterial effects of long-chain polyphosphates (sodium polyphosphate glassy [SPG] and sodium ultraphosphate [UP]) to Staphylococcus aureus ISP40 8325 could be attributed to damage to the cell envelope (cell wall or cell membrane). Also, Ca2+ (0.01 M) or Mg2+ (0.01 M) reversed the bactericidal and bacteriolytic effects of polyphosphates in S. aureus. In the present study, 0.4 M sodium chloride (NaCl) protected the cells from leakage caused by SPG and 0.6 M NaCl protected the cells from leakage by UP. Polymyxin, a peptide antibiotic that causes cell membrane damage, induced leakage even in the presence of 0.6 M NaCl. In the presence of 0.4 M NaCl, bacterial leakage was significantly reduced by disodium ethylenediamine tetraacetate (EDTA), a metal chelator that causes cell wall damage. Bacterial leakage by polyphosphates was significantly greater at pH 8 than at pH 6, which suggested that metal-ion chelation was involved in the antibacterial mechanism. A dialysis membrane (MWCO 100) was used to separate free metal and polyphosphate-bound metal. Levels of free Ca2+ and Mg2+ in polyphosphate-treated cells were significantly lower than those of the cells without polyphosphate. This free-metal dialysis study provided Chemical evidence to show that long-chain polyphosphates interacted with S. aureus cell walls by a metal-ion chelation mechanism. In addition, long-chain polyphosphates were shown to bind to the cell wall, chelate metals, and remain bound without releasing metal ions from the cell wall into the suspending medium. A hypothesis is proposed in which the antibacterial mechanism of long-chain polyphosphates is caused by binding of long-chain polyphosphates to the cell wall of early-exponential phase cells of S. aureus ISP40 8325. The polyphosphates chelate structurally essential metals (Ca2+ and Mg2+) of the cell wall, resulting in bactericidal and bacteriolytic effects. The structurally essential metals probably form cross bridges between the teichoic acid chains in the cell walls of gram-positive bacteria.

scholarly journals Two-component system VraSR positively modulates the regulation of cell-wall biosynthesis pathway in Staphylococcus aureus

2004 ◽  
Vol 49 (3) ◽  
pp. 807-821 ◽  
Author(s):  
Makoto Kuroda ◽  
Hiroko Kuroda ◽  
Taku Oshima ◽  
Fumihiko Takeuchi ◽  
Hirotada Mori ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cell Wall Biosynthesis ◽  
Biosynthesis Pathway ◽  
Two Component System ◽  
Component System ◽  
Two Component

scholarly journals Complete Reconstitution of the Vancomycin-Intermediate Staphylococcus aureus Phenotype of Strain Mu50 in Vancomycin-Susceptible S. aureus

2016 ◽  
Vol 60 (6) ◽  
pp. 3730-3742 ◽  
Author(s):  
Yuki Katayama ◽  
Miwa Sekine ◽  
Tomomi Hishinuma ◽  
Yoshifumi Aiba ◽  
Keiichi Hiramatsu
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Mutant Strain ◽  
Vancomycin Resistance ◽  
Wall Thickening ◽  
Cell Physiology ◽  
Content Type ◽  
Sequence Deletion ◽  
Quadruple Mutant ◽  
Genetic Events

Complete reconstitution of the vancomycin-intermediateStaphylococcus aureus(VISA) phenotype of strain Mu50 was achieved by sequentially introducing mutations into six genes of vancomycin-susceptibleS. aureus(VSSA) strain N315ΔIP. The six mutated genes were detected in VISA strain Mu50 but not in N315ΔIP. Introduction of the mutation Ser329Leu intovraS, encoding the sensor histidine kinase of thevraSRtwo-component regulatory (TCR) system, and another mutation, Glu146Lys, intomsrR, belonging to the LytR-CpsA-Psr (LCP) family, increased the level of vancomycin resistance to that detected in heterogeneous vancomycin-intermediateS. aureus(hVISA) strain Mu3. Introduction of two more mutations, Asn197Ser intograRof thegraSRTCR system and His481Tyr intorpoB, encoding the β subunit of RNA polymerase, converted the hVISA strain into a VISA strain with the same level of vancomycin resistance as Mu50. Surprisingly, however, the constructed quadruple mutant strain ΔIP4 did not have a thickened cell wall, a cardinal feature of the VISA phenotype. Subsequent study showed that cell wall thickening was an inducible phenotype in the mutant strain, whereas it was a constitutive one in Mu50. Finally, introduction of the Ala297Val mutation intofdh2, which encodes a putative formate dehydrogenase, or a 67-amino-acid sequence deletion intosle1[sle1(Δ67aa)], encoding the hydrolase ofN-acetylmuramyl-l-alanine amidase in the peptidoglycan, converted inducible cell wall thickening into constitutive cell wall thickening.sle1(Δ67aa) was found to cause a drastic decrease in autolysis activity. Thus, all six mutated genes required for acquisition of the VISA phenotype were directly or indirectly involved in the regulation of cell physiology. The VISA phenotype seemed to be achieved through multiple genetic events accompanying drastic changes in cell physiology.

scholarly journals Oritavancin Exhibits Dual Mode of Action to Inhibit Cell-Wall Biosynthesis in Staphylococcus aureus

2008 ◽  
Vol 377 (1) ◽  
pp. 281-293 ◽  
Author(s):  
Sung Joon Kim ◽  
Lynette Cegelski ◽  
Dirk Stueber ◽  
Manmilan Singh ◽  
Evelyne Dietrich ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Mode Of Action ◽  
Cell Wall Biosynthesis ◽  
Dual Mode
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