Publications by authors named "Samanthi Waidyarachchi"

Article Synopsis
  • Scientists created new medicines called spectinamides to help treat tuberculosis (TB) more effectively.
  • One of these, named MBX-4888A, works well with other TB drugs like rifampin and pyrazinamide in mice.
  • The research showed that using MBX-4888A can help shorten the treatment time for TB and seems to be safe for long-term use in mice.
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Article Synopsis
  • Spectinamides are new medicines that help fight TB (tuberculosis), modified to work better in the body.
  • In studies with mice, one type called MBX-4888A showed it could improve treatment when used with other TB drugs.
  • This research tested how well it works in different mouse models, showing it's safe and might help cure TB faster.
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(), a nontuberculous mycobacterial (NTM) species, is an emerging pathogen with high intrinsic drug resistance. Current standard-of-care therapy results in poor outcomes, demonstrating the urgent need to develop effective antimycobacterial regimens. Through synthetic modification of spectinomycin (SPC), we have identified a distinct structural subclass of N-ethylene linked aminomethyl SPCs (eAmSPCs) that are up to 64-fold more potent against over the parent SPC.

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Article Synopsis
  • Researchers have developed a promising antimalarial drug lead, MBX-4055, by modifying a previously identified inhibitor to improve its bioavailability and stability while maintaining potency against malaria parasites.
  • MBX-4055 effectively enhances the permeability of host erythrocytes by targeting a specific plasmodial surface anion channel, an essential player in the parasite's nutrient acquisition.
  • The novel pyridazinone compounds show excellent absorption and tolerance in living organisms and are less likely to lead to drug resistance, making them a significant advancement in antimalarial treatment options.
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New antibiotics that are active against multi-drug-resistant strains and difficult-to-treat bacterial infections are needed. Synthetic modification of spectinomycin, a bacterial protein synthesis inhibitor, has been shown to increase antibacterial activity compared with spectinomycin. Aminomethyl spectinomycins are active against Gram-negative and Gram-positive bacterial pathogens.

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The most frequent ailment for which antibiotics are prescribed is otitis media (ear infections), which is most commonly caused by , , and Treatment of otitis media is complicated by the fact that the bacteria in the middle ear typically form biofilms, which can be recalcitrant to antibiotic treatment. Furthermore, bacterial respiratory infections can be greatly exacerbated by viral coinfection, which is particularly evidenced by the synergy between influenza and In this study, we sought to ascertain the efficacy of aminomethyl spectinomycin lead 1950, an effective antibacterial agent both and against in the context of complex respiratory infections and acute otitis media. A single dose of 1950 significantly reduced bacterial burden in the respiratory tract for all three pathogens, even when species were present in a coinfection model.

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Bacterial sexually transmitted infections are widespread and common, with (gonorrhea) and (chlamydia) being the two most frequent causes. If left untreated, both infections can cause pelvic inflammatory disease, infertility, ectopic pregnancy, and other sequelae. The recommended treatment for gonorrhea is ceftriaxone plus azithromycin (to empirically treat chlamydial coinfections).

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Spectinamides are a novel class of antitubercular agents with the potential to treat drug-resistant tuberculosis infections. Their antitubercular activity is derived from both ribosomal affinity and their ability to overcome intrinsic efflux mediated by the Mycobacterium tuberculosis Rv1258c efflux pump. This study explores the structure-activity relationships through analysis of 50 targeted spectinamides.

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The antibiotic spectinomycin is a potent inhibitor of bacterial protein synthesis with a unique mechanism of action and an excellent safety index, but it lacks antibacterial activity against most clinically important pathogens. A series of N-benzyl-substituted 3'-(R)-3'-aminomethyl-3'-hydroxy spectinomycins was developed on the basis of a computational analysis of the aminomethyl spectinomycin binding site and structure-guided synthesis. These compounds had ribosomal inhibition values comparable to spectinomycin but showed increased potency against the common respiratory tract pathogens Streptococcus pneumoniae, Haemophilus influenzae, Legionella pneumophila, and Moraxella catarrhalis, as well as the sexually transmitted bacteria Neisseria gonorrhoeae and Chlamydia trachomatis.

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Although the classical antibiotic spectinomycin is a potent bacterial protein synthesis inhibitor, poor antimycobacterial activity limits its clinical application for treating tuberculosis. Using structure-based design, we generated a new semisynthetic series of spectinomycin analogs with selective ribosomal inhibition and excellent narrow-spectrum antitubercular activity. In multiple murine infection models, these spectinamides were well tolerated, significantly reduced lung mycobacterial burden and increased survival.

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