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Recent Developments in Therapies and Strategies Against COVID-19
Published in Hanadi Talal Ahmedah, Muhammad Riaz, Sagheer Ahmed, Marius Alexandru Moga, The Covid-19 Pandemic, 2023
Misbah Hameed, M. Zia-Ul-Haq, Marius Moga
Azithromycin is an antibiotic used against various bacterial infections. It belongs to the macrolide group of antibiotics. Azithromycin prevents bacterial growth by inhibiting the synthesis of protein. It binds to the 50S ribosomal subunit of the bacterial cell and inhibits the process of translation of mRNA. It is used in chest infections such as nose and throat infections, pneumonia, skin infection, and sexually transmitted infections. It has been suggested to be used in COVID-19 infection. It has been proven that Azithroymcin has good activity against Ebola and Zika viruses. Previously, has been part of adjunctive therapy to provide some immunomodulatory and anti-inflammatory results along with bacterial coverage of some respiratory tract infections like influenza. Currently, azithromycin has been tested in a number of trials along with HCQ as a treatment strategy in COVID-19 patients.
Tetracycline
Published in Anton C. de Groot, Monographs in Contact Allergy, 2021
Tetracycline is a broad-spectrum naphthacene antibiotic produced semisynthetically from chlortetracycline, an antibiotic isolated from the bacterium Streptomyces aureofaciens. It exerts a bacteriostatic effect on bacteria by binding reversibly to the bacterial 30S ribosomal subunit and blocking incoming aminoacyl tRNA from binding to the ribosome acceptor site. It also binds to some extent to the bacterial 50S ribosomal subunit and may alter the cytoplasmic membrane causing intracellular components to leak from bacterial cells. Tetracycline is used to treat a wide variety of infections caused by susceptible bacteria and is also widely utilized in the treatment of acne vulgaris and acne conglobata. In pharmaceutical products, tetracycline is employed as tetracycline hydrochloride (CAS number 64-75-5, EC number 200-593-8, molecular formula C22H25CIN2O8) (1).
Analysis of Small RNA Species: Phylogenetic Trends
Published in S. K. Dutta, DNA Systematics, 2019
Mirko Beljanski, Liliane Le Goff
Reconstitution experiments have demonstrated the importance of 5S rRNA as a structural component in the 50S ribosomal subunit.45,61 50S ribosomes that reconstitute without 5S rRNA are void of several proteins and show greatly reduced biological activity. All prokaryote 5S rRNAs tested were active in reconstituting B. stearothermophilus 50S ribosomal subunits, while eukaryotic 5S RNAs were not.62 Secondary structural features in the 5S RNA are important for biological activity.
Neonatal ocular prophylaxis in the United States: is it still necessary?
Published in Expert Review of Anti-infective Therapy, 2023
Susannah Franco, Margaret R. Hammerschlag
Erythromycin, the oldest antibiotic of the broad-spectrum macrolide class, exhibits its bacteriostatic action by binding to the 50S bacterial ribosomal subunit. This prevents the formation of peptide bonds and consequently the translocation of the peptidyl-tRNA. Binding to the 50S ribosomal subunit also blocks the peptide exit channel by interacting with 23S ribosomal RNA (rRNA) located within the 50S ribosomal subunit. Protein synthesis is ultimately inhibited due to the incomplete release of polypeptides from the bacterial ribosomes [20–22]. Bacterial resistance mechanisms against macrolides are thought to be genetic, either via specific nucleotide alterations in 23S rRNA or through modifications of the 23S rRNA subunit by rRNA methylases that prevent macrolide binding. Another theorized resistance mechanism is an overexpression of efflux pumps, particularly the MtrCDE efflux pump [20].
Strategies for targeting RNA with small molecule drugs
Published in Expert Opinion on Drug Discovery, 2023
Christopher L. Haga, Donald G. Phinney
Similarly, oxazolidinone-based antibiotics are known to bind to the peptidyltransferase center (PTC) of the 50S ribosomal subunit, preventing the formation of the initiation complex itself, thus resulting in inhibition of protein synthesis [36]. Oxazolidinone-based antibiotics are characterized by a core structure consisting of an oxazolidone ring with the S configuration of the substituent at C5, linked to an acylaminomethyl group and an N-aryl substituent [37]. The 50S ribosomal subunit is composed of 5S rRNA, the 23S rRNA, and structural proteins. Despite binding to rRNA in the ribosomal complex, the mechanism of action of oxazolidinone-based antibiotics differs greatly from aminoglycoside-based antibiotics and does not affect peptidyl elongation nor translational termination. Oxazolidinone-based antibiotics crosslink the 23S rRNA with other structural ribosomal proteins, binding to the universally conserved U2585 rRNA nucleotide, thereby stabilizing the base in an orientation that induces a nonproductive conformation of the PTC. Importantly, other RNA structures have been shown to efficiently bind to oxazolidinone derivatives and analogs. For instance, oxazolidinone analogs have been shown to bind to the non-ribosomal RNA T-box antiterminator, a key component of the T-box riboswitch [38] responsible for regulating RNA transcription in response to metabolic effector molecules in Gram-positive bacteria.
Novel linezolid loaded bio-composite films as dressings for effective wound healing: experimental design, development, optimization, and antimicrobial activity
Published in Drug Delivery, 2022
Dina Saeed Ghataty, Reham Ibrahim Amer, Reham Wasfi, Rehab Nabil Shamma
Numerous wound dressings are generally loaded up with antimicrobials to perform against contagious microorganisms and avoid undesirable events such as bacteremia and sepsis. Topical antibiotics play an essential role in treating and preventing abundant dermal bacterial infections due to abrasion, injury, and surgery (Hafezi et al., 2019). Linezolid (LNZ) is a synthetic oxazolidinone antibiotic that has been approved by the Food and Drug Administration (FDA) for the treatment of wound pathogens initiated by Gram-positive bacteria such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci (VRE), penicillin-resistant Streptococcus pneumonia and glycopeptide intermediate Staphylococcus aureus (GISA) (Ma et al., 2015; Hedaya et al., 2017; Carreño et al., 2020). LNZ inhibits the protein synthesis via attaching to the 50S ribosomal subunit, therefore obstructing bacterial growth (Haider et al., 2022). As topical wound dressings, LNZ treats various wounds caused by burns and diabetic foot ulcers due to its effectiveness (Ma et al., 2015; Haider et al., 2022).