scholarly journals Ribosome Rescue Pathways in Bacteria

2021 ◽  
Vol 12 ◽  
Author(s):  
Claudia Müller ◽  
Caillan Crowe-McAuliffe ◽  
Daniel N. Wilson
Keyword(s):  
Messenger Rna ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Polypeptide Chain ◽  
Drug Resistant ◽  
Bacterial Survival ◽  
Gram Positive Bacteria ◽  
Small Protein B ◽  
Recent Developments ◽  
Rescue System

Ribosomes that become stalled on truncated or damaged mRNAs during protein synthesis must be rescued for the cell to survive. Bacteria have evolved a diverse array of rescue pathways to remove the stalled ribosomes from the aberrant mRNA and return them to the free pool of actively translating ribosomes. In addition, some of these pathways target the damaged mRNA and the incomplete nascent polypeptide chain for degradation. This review highlights the recent developments in our mechanistic understanding of bacterial ribosomal rescue systems, including drop-off, trans-translation mediated by transfer-messenger RNA and small protein B, ribosome rescue by the alternative rescue factors ArfA and ArfB, as well as Bacillus ribosome rescue factor A, an additional rescue system found in some Gram-positive bacteria, such as Bacillus subtilis. Finally, we discuss the recent findings of ribosome-associated quality control in particular bacterial lineages mediated by RqcH and RqcP. The importance of rescue pathways for bacterial survival suggests they may represent novel targets for the development of new antimicrobial agents against multi-drug resistant pathogenic bacteria.

Evaluation of antibacterial, teratogenicity and antibiofilm effect of sulfated chitosans extracted from marine waste against microorganism

2021 ◽  
pp. 088391152110142
Author(s):  
Velu Gomathy ◽  
Venkatesan Manigandan ◽  
Narasimman Vignesh ◽  
Aavula Thabitha ◽  
Ramachandran Saravanan
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Inhibitory Effect ◽  
Diffusion Method ◽  
Marine Litter ◽  
Ionization Time ◽  
Gram Positive Bacteria ◽  
Mineral Components ◽  
Ft Ir

Biofilms play a key role in infectious diseases, as they may form on the surface and persist after treatment with various antimicrobial agents. The Staphylococcus aureus, Klebsiella pneumoniae, S. typhimurium, P. aeruginosa, and Escherichia coli most frequently associated with medical devices. Chitosan sulphate from marine litter (SCH-MW) was extracted and the mineral components were determined using atomic absorption spectroscopy (AAS). The degree of deacetylation (DA) of SCH was predicted 50% and 33.3% in crab and shrimp waste respectively. The elucidation of the structure of the SCH-MW was portrayed using FT-IR and 1H-NMR spectroscopy. The molecular mass of SCH-MW was determined with Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF). The teratogenicity of SCH-MW was characterized by the zebrafish embryo (ZFE) model. Antimicrobial activity of SCH-MW was tested with the agar well diffusion method; the inhibitory effect of SCH-MW on biofilm formation was assessed in 96 flat well polystyrene plates. The result revealed that a low concentration of crab-sulfated chitosan inhibited bacterial growth and significantly reduced the anti-biofilm activity of gram-negative and gram-positive bacteria relatively to shrimp. It is potentially against the biofilm formation of pathogenic bacteria.

scholarly journals Physics Comes to the Aid of Medicine—Clinically-Relevant Microorganisms through the Eyes of Atomic Force Microscope

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 969
Author(s):  
Mateusz Cieśluk ◽  
Piotr Deptuła ◽  
Ewelina Piktel ◽  
Krzysztof Fiedoruk ◽  
Łukasz Suprewicz ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Antimicrobial Agents ◽  
Antimicrobial Treatment ◽  
Point Of View ◽  
Diagnostic Methods ◽  
Drug Resistant ◽  
Bacterial Strains ◽  
Force Microscopy ◽  
Atomic Force ◽  
Recent Developments

Despite the hope that was raised with the implementation of antibiotics to the treatment of infections in medical practice, the initial enthusiasm has substantially faded due to increasing drug resistance in pathogenic microorganisms. Therefore, there is a need for novel analytical and diagnostic methods in order to extend our knowledge regarding the mode of action of the conventional and novel antimicrobial agents from a perspective of single microbial cells as well as their communities growing in infected sites, i.e., biofilms. In recent years, atomic force microscopy (AFM) has been mostly used to study different aspects of the pathophysiology of noninfectious conditions with attempts to characterize morphological and rheological properties of tissues, individual mammalian cells as well as their organelles and extracellular matrix, and cells’ mechanical changes upon exposure to different stimuli. At the same time, an ever-growing number of studies have demonstrated AFM as a valuable approach in studying microorganisms in regard to changes in their morphology and nanomechanical properties, e.g., stiffness in response to antimicrobial treatment or interaction with a substrate as well as the mechanisms behind their virulence. This review summarizes recent developments and the authors’ point of view on AFM-based evaluation of microorganisms’ response to applied antimicrobial treatment within a group of selected bacteria, fungi, and viruses. The AFM potential in development of modern diagnostic and therapeutic methods for combating of infections caused by drug-resistant bacterial strains is also discussed.

scholarly journals Genetically Encoded Photosensitizers as Light-Triggered Antimicrobial Agents

2019 ◽  
Vol 20 (18) ◽  
pp. 4608 ◽  
Author(s):  
Fabienne Hilgers ◽  
Nora Lisa Bitzenhofer ◽  
Yannic Ackermann ◽  
Alina Burmeister ◽  
Alexander Grünberger ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Fluorescent Protein ◽  
Photophysical Properties ◽  
Type I ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Intracellular Expression ◽  
Global Concern ◽  
Green Fluorescent

Diseases caused by multi-drug resistant pathogens have become a global concern. Therefore, new approaches suitable for treating these bacteria are urgently needed. In this study, we analyzed genetically encoded photosensitizers (PS) related to the green fluorescent protein (GFP) or light-oxygen-voltage (LOV) photoreceptors for their exogenous applicability as light-triggered antimicrobial agents. Depending on their specific photophysical properties and photochemistry, these PSs can produce different toxic ROS (reactive oxygen species) such as O2•− and H2O2 via type-I, as well as 1O2 via type-II reaction in response to light. By using cell viability assays and microfluidics, we could demonstrate differences in the intracellular and extracellular phototoxicity of the applied PS. While intracellular expression and exogenous supply of GFP-related PSs resulted in a slow inactivation of E. coli and pathogenic Gram-negative and Gram-positive bacteria, illumination of LOV-based PSs such as the singlet oxygen photosensitizing protein SOPP3 resulted in a fast and homogeneous killing of these microbes. Furthermore, our data indicate that the ROS type and yield as well as the localization of the applied PS protein can strongly influence the antibacterial spectrum and efficacy. These findings open up new opportunities for photodynamic inactivation of pathogenic bacteria.

Toxicity of hydrogen peroxide produced by electroplated coatings to pathogenic bacteria

1998 ◽  
Vol 44 (5) ◽  
pp. 441-447 ◽  
Author(s):  
Zhi-Hong Zhao ◽  
Yoshikazu Sakagami ◽  
Tetsuya Osaka
Keyword(s):  
Hydrogen Peroxide ◽  
Metal Ions ◽  
Pathogenic Bacteria ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Survival Rates ◽  
Gram Negative Bacteria ◽  
Bacterial Survival ◽  
Gram Positive Bacteria ◽  
Inhibitory Ability ◽  
Nickel Zinc

The ability of various electroplated coatings (cobalt, zinc, copper, and cobalt-containing alloys of nickel, zinc, chromium, etc.) to inhibit the growth of pathogenic bacteria (Gram-positive bacteria Enterococcus faecalis and methicillin-resistant Staphylococcus aureus and Gram-negative bacteria Escherichia coli, Pseudomonas aeruginosa, andKlebsiella pneumoniae) was determined by a drop-method antibacterial experiment. The amounts of H2O2 produced and metal ions dissolved from the surfaces of various electroplated coatings were measured and it was found that the inhibitory ability of coatings corresponded to the amounts of H2O2 produced. The more significant the inhibition of the coating to bacterial growth, the greater the amount of H2O2 production. In addition, the bacterial survival rates on the surfaces of coatings were almost zero when H2O2 was produced in amounts greater than 10-6 mmol/cm2. However, the dominant concentrations of metal ions dissolved from coatings were outside of the bacterial lethal range.Key words: electroplated coatings, pathogenic bacteria, inhibitory ability, hydrogen peroxide.

scholarly journals Mechanistic Study of Synergistic Antimicrobial Effects between Poly (3-hydroxybutyrate) Oligomer and Polyethylene Glycol

2020 ◽  
Author(s):  
Ziheng Zhang ◽  
Jun Li ◽  
Linlin Ma ◽  
Xingxing Yang ◽  
Bin Fei ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Antimicrobial Agents ◽  
Antimicrobial Effect ◽  
Mechanistic Study ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Drug Resistant ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Drug Resistant Bacteria

We reported previously that poly (3-hydroxybutyrate) (PHB) oligomer is an effective antimicrobial agent against gram-positive bacteria, gram-negative bacteria, fungi and multi-drug resistant bacteria. In this work, it was further found that polyethylene glycol (PEG) can promote the antimicrobial effect of PHB oligomer synergistically. Three hypothetic mechanisms were proposed, that is, generation of new antimicrobial components, degradation of PHB macromolecules and dissolution/dispersion of PHB oligomer by PEG. With a series of systematic experiments and characterizations of HPLC-MS, it was deducted that dissolution/dispersion of PHB oligomer dominated the synergistic antimicrobial effect between PHB oligomer and PEG. This work demonstrates a way for promoting antimicrobial effect of PHB oligomer and other antimicrobial agents through improving hydrophilicity.

scholarly journals Brief survey on organometalated antibacterial drugs and metal-based materials with antibacterial activity

2021 ◽  
Author(s):  
Przemysław Biegański ◽  
Łukasz Szczupak ◽  
Manuel Arruebo ◽  
Konrad Kowalski
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Drug Resistant ◽  
Antibacterial Drugs ◽  
Recent Developments ◽  
Resistant Strains ◽  
Drug Resistant Strains

Recent developments in the field of organometalated antibacterial drugs and metal-based materials with antibacterial activity are reviewed. They emerge as attractive candidates for combating pathogenic bacteria including drug resistant strains.

scholarly journals Structures of tmRNA and SmpB as they transit through the ribosome

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Charlotte Guyomar ◽  
Gaetano D’Urso ◽  
Sophie Chat ◽  
Emmanuel Giudice ◽  
Reynald Gillet
Keyword(s):  
High Resolution ◽  
Messenger Rna ◽  
Elongation Factor ◽  
Messenger Rnas ◽  
Small Protein ◽  
Small Protein B ◽  
High Resolution Structure ◽  
Rescue System ◽  
Shed Light ◽  
Resolution Structure

AbstractIn bacteria, trans-translation is the main rescue system, freeing ribosomes stalled on defective messenger RNAs. This mechanism is driven by small protein B (SmpB) and transfer-messenger RNA (tmRNA), a hybrid RNA known to have both a tRNA-like and an mRNA-like domain. Here we present four cryo-EM structures of the ribosome during trans-translation at resolutions from 3.0 to 3.4 Å. These include the high-resolution structure of the whole pre-accommodated state, as well as structures of the accommodated state, the translocated state, and a translocation intermediate. Together, they shed light on the movements of the tmRNA-SmpB complex in the ribosome, from its delivery by the elongation factor EF-Tu to its passage through the ribosomal A and P sites after the opening of the B1 bridges. Additionally, we describe the interactions between the tmRNA-SmpB complex and the ribosome. These explain why the process does not interfere with canonical translation.

scholarly journals The glmS ribozyme: use of a small molecule coenzyme by a gene-regulatory RNA

2010 ◽  
Vol 43 (4) ◽  
pp. 423-447 ◽  
Author(s):  
Adrian R. Ferré-D'Amaré
Keyword(s):  
Small Molecule ◽  
Conformational Changes ◽  
Active Site ◽  
Messenger Rna ◽  
Pathogenic Bacteria ◽  
Experimental System ◽  
Gram Positive Bacteria ◽  
New Antibiotics ◽  
Glms Ribozyme ◽  
Essential Enzyme

AbstractThe glmS ribozyme is the first known example of a natural ribozyme that has evolved to require binding of an exogenous small molecule for activity. In Gram-positive bacteria, this RNA domain is part of the messenger RNA (mRNA) encoding the essential enzyme that synthesizes glucosamine-6-phosphate (GlcN6P). When present at physiologic concentration, this small molecule binds to the glmS ribozyme and uncovers a latent self-cleavage activity that ultimately leads to degradation of the mRNA. Biochemical and structural studies reveal that the RNA adopts a rigid fold stabilized by three pseudoknots and the packing of a peripheral domain against the ribozyme core. GlcN6P binding to this pre-organized RNA does not induce conformational changes; rather, the small molecule functions as a coenzyme, providing a catalytically essential amine group to the active site. The ribozyme is not a passive player, however. Active site functional groups are essential for catalysis, even in the presence of GlcN6P. In addition to being a superb experimental system with which to analyze how RNA catalysts can exploit small molecule coenzymes to broaden their chemical versatility, the presence of the glmS ribozyme in numerous pathogenic bacteria make this RNA an attractive target for the development of new antibiotics and antibacterial strategies.

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