Conformational analysis of bacterial cell wall peptides indicates how particular conformations have influenced the evolution of penicillin-binding proteins, ?-lactam antibiotics and antibiotic resistance mechanisms

2002 ◽  
Vol 15 (3) ◽  
pp. 113-125 ◽  
Author(s):  
Barry M. Grail ◽  
John W. Payne
Keyword(s):  
Cell Wall ◽  
Antibiotic Resistance ◽  
Conformational Analysis ◽  
Bacterial Cell ◽  
Binding Proteins ◽  
Resistance Mechanisms ◽  
Bacterial Cell Wall ◽  
Penicillin Binding Proteins

scholarly journals Interplay between Penicillin-binding proteins and SEDS proteins promotes bacterial cell wall synthesis

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Sophie Leclercq ◽  
Adeline Derouaux ◽  
Samir Olatunji ◽  
Claudine Fraipont ◽  
Alexander J. F. Egan ◽  
...  
Keyword(s):  
Cell Wall ◽  
Bacterial Cell ◽  
Binding Proteins ◽  
Bacterial Cell Wall ◽  
Cell Wall Synthesis ◽  
Penicillin Binding Proteins

scholarly journals Single-Walled Carbon Nanotube-Assisted Antibiotic Delivery and Imaging in S. epidermidis Strains Addressing Antibiotic Resistance

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1685 ◽  
Author(s):  
Afeefah Khazi-Syed ◽  
Md Tanvir Hasan ◽  
Elizabeth Campbell ◽  
Roberto Gonzalez-Rodriguez ◽  
Anton V. Naumov
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Antibiotic Resistance ◽  
Bacterial Cell ◽  
Mammalian Cells ◽  
Near Infrared ◽  
Bacterial Cell Wall ◽  
Near Infrared Fluorescence ◽  
Single Walled Carbon ◽  
Antibiotic Delivery

Although conventional antibiotics have evolved as a staple of modern medicine, increasing antibiotic resistance and the lack of antibiotic efficacy against new bacterial threats is becoming a major medical threat. In this work, we employ single-walled carbon nanotubes (SWCNTs) known to deliver and track therapeutics in mammalian cells via intrinsic near-infrared fluorescence as carriers enhancing antibacterial delivery of doxycycline and methicillin. SWCNTs dispersed in water by antibiotics without the use of toxic bile salt surfactants facilitate efficacy enhancement for both antibiotics against Staphylococcus epidermidis strain showing minimal sensitivity to methicillin. Doxycycline to which the strain did not show resistance in complex with SWCNTs provides only minor increase in efficacy, whereas the SWCNTs/methicillin complex yields up to 40-fold efficacy enhancement over antibiotics alone, suggesting that SWCNT-assisted delivery may circumvent antibiotic resistance in that bacterial strain. At the same time SWCNT/antibiotic formulations appear to be less toxic to mammalian cells than antibiotics alone suggesting that nanomaterial platforms may not restrict potential biomedical applications. The improvement in antibacterial performance with SWCNT delivery is tested via 3 independent assays—colony count, MIC (Minimal Inhibitory Concentration) turbidity and disk diffusion, with the statistical significance of the latter verified by ANOVA and Dunnett’s method. The potential mechanism of action is attributed to SWCNT interactions with bacterial cell wall and adherence to the membrane, as substantial association of SWCNT with bacteria is observed—the near-infrared fluorescence microscopy of treated bacteria shows localization of SWCNT fluorescence in bacterial clusters, scanning electron microscopy verifies SWCNT association with bacterial surface, whereas transmission electron microscopy shows individual SWCNT penetration into bacterial cell wall. This work characterizes SWCNTs as novel advantageous antibiotic delivery/imaging agents having the potential to address antibiotic resistance.

scholarly journals Inflammasome Activation by Bacterial Outer Membrane Vesicles Requires Guanylate Binding Proteins

mBio ◽  
2017 ◽  
Vol 8 (5) ◽  
Author(s):  
Ryan Finethy ◽  
Sarah Luoma ◽  
Nichole Orench-Rivera ◽  
Eric M. Feeley ◽  
Arun K. Haldar ◽  
...  
Keyword(s):  
Cell Wall ◽  
Outer Membrane ◽  
Bacterial Cell ◽  
Binding Proteins ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Bacterial Cell Wall ◽  
Cell Wall Component ◽  
Gram Negative

ABSTRACT The Gram-negative bacterial cell wall component lipopolysaccharide (LPS) is recognized by the noncanonical inflammasome protein caspase-11 in the cytosol of infected host cells and thereby prompts an inflammatory immune response linked to sepsis. Host guanylate binding proteins (GBPs) promote infection-induced caspase-11 activation in tissue culture models, and yet their in vivo role in LPS-mediated sepsis has remained unexplored. LPS can be released from lysed bacteria as “free” LPS aggregates or actively secreted by live bacteria as a component of outer membrane vesicles (OMVs). Here, we report that GBPs control inflammation and sepsis in mice injected with either free LPS or purified OMVs derived from Gram-negative Escherichia coli. In agreement with our observations from in vivo experiments, we demonstrate that macrophages lacking GBP2 expression fail to induce pyroptotic cell death and proinflammatory interleukin-1β (IL-1β) and IL-18 secretion when exposed to OMVs. We propose that in order to activate caspase-11 in vivo, GBPs control the processing of bacterium-derived OMVs by macrophages as well as the processing of circulating free LPS by as-yet-undetermined cell types. IMPORTANCE The bacterial cell wall component LPS is a strong inducer of inflammation and is responsible for much of the toxicity of Gram-negative bacteria. Bacteria shed some of their cell wall and its associated LPS in the form of outer membrane vesicles (OMVs). Recent work demonstrated that secreted OMVs deliver LPS into the host cell cytosol by an unknown mechanism, resulting in the activation of the proinflammatory LPS sensor caspase-11. Here, we show that activation of cytosolic caspase-11 by OMVs requires additional host factors, the so-called guanylate binding proteins (GBPs). The discovery of GBPs as regulators of OMV-mediated inflammation paves the way toward a mechanistic understanding of the host response toward bacterial OMVs and may lead to effective strategies to ameliorate inflammation induced by bacterial infections. IMPORTANCE The bacterial cell wall component LPS is a strong inducer of inflammation and is responsible for much of the toxicity of Gram-negative bacteria. Bacteria shed some of their cell wall and its associated LPS in the form of outer membrane vesicles (OMVs). Recent work demonstrated that secreted OMVs deliver LPS into the host cell cytosol by an unknown mechanism, resulting in the activation of the proinflammatory LPS sensor caspase-11. Here, we show that activation of cytosolic caspase-11 by OMVs requires additional host factors, the so-called guanylate binding proteins (GBPs). The discovery of GBPs as regulators of OMV-mediated inflammation paves the way toward a mechanistic understanding of the host response toward bacterial OMVs and may lead to effective strategies to ameliorate inflammation induced by bacterial infections.

Role of bacterial cell wall proteinase in antihypertension

2002 ◽  
Vol 22 (1-2) ◽  
pp. 209-222 ◽  
Author(s):  
Bénédicte Flambard
Keyword(s):  
Cell Wall ◽  
Bacterial Cell ◽  
Bacterial Cell Wall
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