scholarly journals Peptidoglycan hydrolysis is required for assembly and activity of the transenvelope secretion complex during sporulation inBacillus subtilis

2013 ◽  
Vol 89 (6) ◽  
pp. 1039-1052 ◽  
Author(s):  
Christopher D. A. Rodrigues ◽  
Kathleen A. Marquis ◽  
Jeffrey Meisner ◽  
David Z. Rudner
Keyword(s):  
Peptidoglycan Hydrolysis

scholarly journals Engineered Lysins With Customized Lytic Activities Against Enterococci and Staphylococci

2020 ◽  
Vol 11 ◽  
Author(s):  
Hana Sakina Binte Muhammad Jai ◽  
Linh Chi Dam ◽  
Lowella Servito Tay ◽  
Jodi Jia Wei Koh ◽  
Hooi Linn Loo ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Catalytic Domain ◽  
Therapeutic Potential ◽  
Multidrug Resistant ◽  
Species Specificity ◽  
Resistant Bacteria ◽  
Modular Architecture ◽  
Narrow Spectrum ◽  
Cell Wall Binding ◽  
Peptidoglycan Hydrolysis

The emergence of multidrug-resistant bacteria has made minor bacterial infections incurable with many existing antibiotics. Lysins are phage-encoded peptidoglycan hydrolases that have demonstrated therapeutic potential as a novel class of antimicrobials. The modular architecture of lysins enables the functional domains – catalytic domain (CD) and cell wall binding domain (CBD) – to be shuffled to create novel lysins. The CD is classically thought to be only involved in peptidoglycan hydrolysis whereas the CBD dictates the lytic spectrum of a lysin. While there are many studies that extended the lytic spectrum of a lysin by domain swapping, few have managed to introduce species specificity in a chimeric lysin. In this work, we constructed two chimeric lysins by swapping the CBDs of two parent lysins with different lytic spectra against enterococci and staphylococci. We showed that these chimeric lysins exhibited customized lytic spectra distinct from the parent lysins. Notably, the chimeric lysin P10N-V12C, which comprises a narrow-spectrum CD fused with a broad-spectrum CBD, displayed species specificity not lysing Enterococcus faecium while targeting Enterococcus faecalis and staphylococci. Such species specificity can be attributed to the narrow-spectrum CD of the chimeric lysin. Using flow cytometry and confocal microscopy, we found that the E. faecium cells that were treated with P10N-V12C are less viable with compromised membranes yet remained morphologically intact. Our results suggest that while the CBD is a major determinant of the lytic spectrum of a lysin, the CD is also responsible in the composition of the final lytic spectrum, especially when it pertains to species-specificity.

scholarly journals β-Lactam Resistance in Methicillin-Resistant Staphylococcus aureus USA300 Is Increased by Inactivation of the ClpXP Protease

2014 ◽  
Vol 58 (8) ◽  
pp. 4593-4603 ◽  
Author(s):  
Kristoffer T. Bæk ◽  
Angelika Gründling ◽  
René G. Mogensen ◽  
Louise Thøgersen ◽  
Andreas Petersen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Envelope ◽  
Penicillin Binding Protein ◽  
Gene Encoding ◽  
Resistance Level ◽  
Methicillin Resistant ◽  
Content Type ◽  
Usa300 Strain ◽  
Mrsa Strains ◽  
Peptidoglycan Hydrolysis

ABSTRACTMethicillin-resistantStaphylococcus aureus(MRSA) has acquired themecAgene encoding a peptidoglycan transpeptidase, penicillin binding protein 2a (PBP2a), which has decreased affinity for β-lactams. Quickly spreading and highly virulent community-acquired (CA) MRSA strains recently emerged as a frequent cause of infection in individuals without exposure to the health care system. In this study, we found that the inactivation of the components of the ClpXP protease substantially increased the β-lactam resistance level of a CA-MRSA USA300 strain, suggesting that the proteolytic activity of ClpXP controls one or more pathways modulating β-lactam resistance. These pathways do not involve the control ofmecAexpression, as the cellular levels of PBP2a were unaltered in theclpmutants. An analysis of the cell envelope properties of theclpXandclpPmutants revealed a number of distinct phenotypes that may contribute to the enhanced β-lactam tolerance. Both mutants displayed significantly thicker cell walls, increased peptidoglycan cross-linking, and altered composition of monomeric muropeptide species compared to those of the wild types. Moreover, changes in Sle1-mediated peptidoglycan hydrolysis and altered processing of the major autolysin Atl were observed in theclpmutants. In conclusion, the results presented here point to an important role for the ClpXP protease in controlling cell wall metabolism and add novel insights into the molecular factors that determine strain-dependent β-lactam resistance.

Cell wall active antibiotics reduce chromosomal DNA fragmentation by peptidoglycan hydrolysis in Staphylococcus aureus

2012 ◽  
Vol 194 (12) ◽  
pp. 967-975 ◽  
Author(s):  
María Tamayo ◽  
Rebeca Santiso ◽  
Jaime Gosálvez ◽  
Germán Bou ◽  
María del Cármen Fernández ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Dna Fragmentation ◽  
Chromosomal Dna ◽  
Peptidoglycan Hydrolysis

scholarly journals Molecular Mechanism of the Peptidoglycan Hydrolysis by FlgJ, A Putative Flagellar Rod Cap Protein From Salmonella

2010 ◽  
Vol 98 (3) ◽  
pp. 248a-249a
Author(s):  
Yuki Kikuchi ◽  
Hideyuki Matsunami ◽  
Midori Yamane ◽  
Katsumi Imada ◽  
Keiichi Namba
Keyword(s):  
Molecular Mechanism ◽  
Peptidoglycan Hydrolysis

scholarly journals DipM is required for peptidoglycan hydrolysis during chloroplast division

2014 ◽  
Vol 14 (1) ◽  
pp. 57 ◽  
Author(s):  
Shin-ya Miyagishima ◽  
Yukihiro Kabeya ◽  
Chieko Sugita ◽  
Mamoru Sugita ◽  
Takayuki Fujiwara
Keyword(s):  
Chloroplast Division ◽  
Peptidoglycan Hydrolysis

Lytic and Nonlytic Mechanism of Inactivation of Gram-Positive Bacteria by Lysozyme under Atmospheric and High Hydrostatic Pressure

2002 ◽  
Vol 65 (12) ◽  
pp. 1916-1923 ◽  
Author(s):  
BARBARA MASSCHALCK ◽  
DAPHNE DECKERS ◽  
CHRIS W. MICHIELS
Keyword(s):  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
Enzymic Activity ◽  
Heat Denaturation ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Egg White Lysozyme ◽  
Membrane Perturbation ◽  
Plate Counts ◽  
Peptidoglycan Hydrolysis

A different behavior was observed in three gram-positive bacteria exposed to hen egg white lysozyme by plate counts and phase-contrast microscopy. The inactivation of Lactobacillus johnsonii was accompanied by spheroplast formation, which is an indication of peptidoglycan hydrolysis. Staphylococcus aureus was resistant to lysozyme and showed no signs of peptidoglycan hydrolysis, and Listeria innocua was inactivated and showed indications of cell leakage but not of peptidoglycan hydrolysis. Under high hydrostatic pressure, S. aureus also became sensitive to lysozyme but did not form spheroplasts and was not lysed. These results suggested the existence of a nonlytic mechanism of bactericidal action of lysozyme on the latter two bacteria, and this mechanism was further studied in L. innocua. Elimination of the enzymic activity of lysozyme by heat denaturation or reduction with β-mercaptoethanol eliminated this bactericidal mechanism. By means of a LIVE/DEAD viability stain based on a membrane-impermeant fluorescent dye, the nonlytic mechanism was shown to involve membrane perturbation. In the absence of lysozyme, high-pressure treatment was shown to induce autolytic activity in S. aureus and L. innocua.

Factors affecting sensitivity of group B streptococci to an exogenous murein hydrolase

1985 ◽  
Vol 31 (5) ◽  
pp. 417-422
Author(s):  
Diane Horne ◽  
Alexander Tomasz
Keyword(s):  
Cell Wall ◽  
Cell Envelope ◽  
Group B Streptococci ◽  
Factors Affecting ◽  
Exogenous Enzyme ◽  
Colony Forming Units ◽  
Peptidoglycan Structure ◽  
Group B ◽  
Peptidoglycan Hydrolysis ◽  
Hydrolysis Of

Group B streptococci treated with cell wall synthesis inhibitors (penicillin or vancomycin) or by a variety of membrane-acting agents are sensitized to the lytic action of exogenous M1 muramidase. Muramidase without a sensitizing agent caused rupture of bacterial chains only, accompanied by the release of a small amount of cell wall peptidoglycan label and an increase of the number of colony-forming units. In combination with sensitizing agents the exogenous muramidase appeared to initiate hydrolysis of biosynthetically new peptidoglycan. Treatment of the cells with chloramphenicol or starvation for nutritionally required amino acids suppressed the rate of cell lysis and peptidoglycan hydrolysis during subsequent sensitization and muramidase treatment of the bacteria. Purified cell walls prepared from the amino acid starved cells were also hydrolyzed with a slower rate by muramidase. It is suggested that agents sensitizing the bacteria to the exogenous muramidase act by perturbing or removing some nonmurein components of the cell envelope which protect the peptidoglycan from the activity of exogenous enzyme. Agents increasing resistance against exogenous muramidase may also cause some alteration in peptidoglycan structure.

scholarly journals SleC Is Essential for Cortex Peptidoglycan Hydrolysis during Germination of Spores of the Pathogenic Bacterium Clostridium perfringens

2009 ◽  
Vol 191 (8) ◽  
pp. 2711-2720 ◽  
Author(s):  
Daniel Paredes-Sabja ◽  
Peter Setlow ◽  
Mahfuzur R. Sarker
Keyword(s):  
Clostridium Perfringens ◽  
Spore Germination ◽  
Dipicolinic Acid ◽  
Pathogenic Bacterium ◽  
Wild Type ◽  
Lytic Enzymes ◽  
Colony Forming Efficiency ◽  
Forming Efficiency ◽  
Peptidoglycan Hydrolysis

ABSTRACT Clostridial spore germination requires degradation of the spore's peptidoglycan (PG) cortex by cortex-lytic enzymes (CLEs), and two Clostridium perfringens CLEs, SleC and SleM, degrade cortex PG in vitro. We now find that only SleC is essential for cortex hydrolysis and viability of C. perfringens spores. C. perfringens sleC spores did not germinate completely with nutrients, KCl, or a 1:1 chelate of Ca2+ and dipicolinic acid (Ca-DPA), and the colony-forming efficiency of sleC spores was 103-fold lower than that of wild-type spores. However, sleC spores incubated with various germinants released most of their DPA, although slower than wild-type or sleM spores, and DPA release from sleC sleM spores was very slow. In contrast, germination and viability of sleM spores were similar to that of wild-type spores, although sleC sleM spores had 105-fold-lower viability. These results allow the following conclusions about C. perfringens spore germination: (i) SleC is essential for cortex hydrolysis; (ii) although SleM can degrade cortex PG in vitro, this enzyme is not essential; (iii) action of SleC alone or with SleM can accelerate DPA release; and (iv) Ca-DPA does not trigger spore germination by activation of CLEs.

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