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Here, we report for the first time, green-synthesized selenium nanoparticles (SeNPs) using pharmacologically potent herb of Polygonum bistorta Linn. for multiple biomedical applications. In the study, a facile and an eco-friendly approach is utilized for synthesis of SeNPs using an aqueous roots extract of P. bistorta Linn. followed by extensive characterization via Fourier transform infrared spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Energy Dispersive X-Ray (EDX) analysis. The XRD and FTIR data determine the phase composition and successful capping of plant extract onto the surface of NPs while SEM and TEM micrographic examination reveals the elliptical and spherical morphology of the particles with a mean size of 69 ± 23 nm. After comprehensive characterization, the NPs are investigated for antifungal, antibacterial, antileishmanial, antioxidant, and biocompatibility properties. The study reveals that Polygonum bistorta Linn. synthesized SeNPs exhibit significant antibacterial and antifungal activities with Staphylococcus aureus and Fusarium oxysporum inducing the highest zone of inhibition of 14 ± 1.0 mm and 20 ± 1.2 mm, respectively at the concentration of 40 mg/mL. The NPs are also found to have antiparasitic potential against promastigote and amastigote forms of Leishmania tropica. Furthermore, the NPs are discovered to have excellent potential in neutralizing harmful free radicals thus exhibiting considerable antioxidant potential. Most importantly, Polygonum bistorta Linn. synthesized SeNPs showed substantial compatibility against blood cells in vitro studies, which signifies the nontoxic nature of the NPs. The study thus concludes that medicinally important Polygonum bistorta Linn. roots can be utilized as an eco-friendly, sustainable, and green source for the synthesis of pharmacologically potent selenium nanoparticles., Competing Interests: Declarations. Conflict of interest: The authors declare no competing interests. Ethical approval: Not applicable., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Background: Typhoid fever is a fatal disease in humans that is caused by Salmonella typhi. S. typhi infections need immediate antibiotic therapy, and their extensive use has led to multidrug-resistant (MDR) pathogens. The use of bacteriophages is becoming a new way to treat these resistant bacteria. This research was directed to bacteriophage isolation against S. typhi and to determine phage-antibiotic synergism., Aims: To isolate bacteriophages targeting S. typhi, the causative agent of typhoid fever, and investigate their potential synergistic effects when combined with antibiotics., Study Design: A cross-sectional study., Methods: The Widal test was positive; twenty diarrheal stool samples were taken, and for confirmation of S. typhi, different biochemical tests were performed. The disc-diffusion technique was used to determine antimicrobial resistance, and the double agar overlay method was used for bacteriophage isolation from sewage water against S. typhi. To test antibiotic-phage synergism, the S. typhi bacteria was treated by phages together with varying antibiotic concentrations., Results: Eleven samples were positive for S. typhi with black colonies on SS-agar. These were catalase and MR positive with alkali butt on TSI. Clear plaques were observed after the agar overlay. Isolated phages were stable at various pH and temperature levels. Synergism was observed on agar plate. The zone was enlarged when phages were combined with bacterial lawn culture and ciprofloxacin disk. Bacterial growth inhibition had a significant p-value of 0.03 in titration plates, with the phage-ciprofloxacin combination being more effective than the phage and antibiotic alone., Conclusion: The study highlights the synergistic effects of isolated bacteriophages with antibiotics, which are not only effective against S. typhi infection but also decrease antibiotic resistance., (© 2023. The Author(s), under exclusive licence to Royal Academy of Medicine in Ireland.)

The present research paper reports the convenient synthesis, successful characterization, in vitro antibacterial, antifungal, antioxidant potency and biocompatibility of N-acyl-morpholine-4-carbothioamides (5a-5j). The biocompatible derivatives were found to be highly active against the tested bacterial and fungal strains. Moreover, some of the screened N-acyl-morpholine-4-carbothioamides exhibited excellent antioxidant potential. Docking simulation provided additional information about possibilities of their inhibitory potential against RNA. It has been predicted by in silico investigation of the binding pattern that compounds 5a and 5j can serve as the potential surrogate for design of novel and potent antibacterial agents. The results for the in vitro bioassays were promising with the identification of compounds 5a and 5j as the lead and selective candidate for RNA inhibition. Results of the docking computations further ascertained the inhibitory potential of compound 5a. Based on the in silico studies, it can be suggested that compounds 5a and 5j can serve as a structural model for the design of antibacterial agents with better inhibitory potential. Binding mode of compound 5j inside the active site of RNA in 3D space. 5j displayed highest antibacterial potential than the reference drug ampicillin with ZOI 10.50 mm against Staphylococcus aureus. 5j also displayed highest antifungal potential than the reference drug amphotericin B with ZOI 18.20 mm against Fusarium solani.

Lichens are composite organisms, comprising of a fungus (mycobiont) and a blue-green alga (photobiont). Along with the mycobiont, numerous non-obligate microfungi live in lichen thalli. These microfungi are called endolichenic fungi (ELF). In recent years, the ELF are emerging as promising natural sources because of their capability to exert unique drug molecules. The current study aimed to isolate the ELF from the lichen, Usnea longissima Ach., to control of biofilm formation and quorum sensing phenomenon in Pseudomonas aeruginosa PAO1, an opportunistic multidrug resistance pathogen that uses quorum sensing network to produce an array of pathogenic agents. Therefore, inhibiting quorum sensing to manage the infection caused by PAO1 could be the paramount alternative approach to conventional antibiotics. The isolated ELF was identified by amplifying the long subunit region of the fungal genome. The extracted metabolites of ELF (MELE) using the acetone solvent was further investigated for anti-quorum sensing activity using the biomarker strain Chromobacterium violaceum 12472 which exerts violacein pigment via the AHL mediated quorum sensing signalling. Moreover, the effect of MELE was also evaluated on the production of virulence factors and biofilm formation of P. aeruginosa PAO1. The molecular identification revealed that ELF (accession number MN171299) exhibited 100% similarity with Aspergillus quandricinctus strain CBS 135.52. The MELE showed significant anti-quorum sensing activity at the concentration of 4 mg/mL without affecting the bacterial cell viability of P. aeruginosa PAO1. The MELE diminished the production of virulence factors, including pyocyanin, protease, elastase, rhamnolipids, and extracellular polysaccharides of P. aeruginosa PAO1 in a concentration-dependent manner. The MELE also disturbed biofilm formation of P. aeruginosa PAO1. The 3-D analysis of biofilm architecture showed that the thickness and surface area covered by microcolonies was decreased as the concentration of MELE was increased. The GC-MS analysis of MELE exhibited that organic acids and fatty acids are major constituents of the MELE. The present study reports first time that the ELF, A. quandricinctus possesses potential to inhibit quorum sensing and biofilm formation of P. aeruginosa and can be further exploited for hospital and healthcare facilities., Competing Interests: Declaration of competing interest The authors declare no potential conflicts of interest among them., (Copyright © 2019. Published by Elsevier Ltd.)

The present study reports the convenient synthesis, spectroscopic characterization, bio-assays and computational evaluation of a novel series of N-acyl-1H-imidazole-1-carbothioamides. The screened derivatives displayed excellent antioxidant activity, moderate antibacterial and antifungal potential. The screened derivatives were found to be highly biocompatible against hRBCs. Molecular docking ascertained the mechanism and mode of action towards the molecular target delineating that ligands and complexes were stabilized at the active site by electrostatic and hydrophobic forces in accordance to the corresponding experimental results. Docking simulation provided additional information about the possibilities of inhibitory potential of the compounds against RNA. Computational evaluation predicted that N-acyl-1H-imidazole-1-carbothioamides 5c and 5g can serve as potential surrogates for hit to lead generation and design of novel antioxidant and antibacterial agents., (© 2020 Wiley-VHCA AG, Zurich, Switzerland.)

Chrysophanol is a unique anthraquinone having broad-spectrum therapeutic potential along with ecological importance. It is the first polyketide that has been reported to be biosynthesized in an organism-specific manner. The traditional Chinese and Korean medicinal systems provide evidence of the beneficial effects of chrysophanol on human health. The global distribution of chrysophanol encountered in two domains of life (bacteria and eukaryota) has motivated researchers to critically evaluate the properties of this compound. A plethora of literature is available on the pharmacological properties of chrysophanol, which include anticancer, hepatoprotective, neuroprotective, anti-inflammatory, antiulcer, and antimicrobial activities. However, the pharmacokinetics and toxicity studies on chrysophanol demand further investigations for it to be used as a drug. This is the first comprehensive review on the natural sources, biosynthetic pathways, and pharmacology of chrysophanol. Here we reviewed recent advancements made on the pharmacokinetics of the chrysophanol. Additionally, we have highlighted the knowledge gaps of its mechanism of action against diseases and toxicity aspects., Competing Interests: The authors declare no conflict of interest.

Silver nanoparticles (AgNP) have been widely applied because of their broad spectrum of antimicrobial activities against bacteria, fungi, and viruses. However, little research has been done to evaluate their effects on Cronobacter sakazakii, an opportunistic pathogen usually infecting infants and having a high fatality rate. The aims of this work were to investigate the antibacterial property of novel, synthesized, positively charged silver nanoparticles against C. sakazakii and to discuss the potential antibacterial mechanisms involved. In this study, the spherical and face-centered cubic silver nanoparticles had a mean particle size of 31.2 nm and were synthesized by reducing Ag + using citrate and dispersed by glycerol and polyvinylpyrrolidone (PVP) under alkaline conditions. Minimum inhibitory concentrations (MIC) and inhibition zone tests showed that the AgNP exhibited strong antibacterial activity against 4 tested C. sakazakii strains with mean MIC of 62.5 to 125 mg/L and average inhibition zone diameters of 13.8 to 16.3 mm. Silver nanoparticles caused cell membrane injury accompanied by adsorption of AgNP onto the cell surface, as shown by changes in cell morphology, cell membrane hyperpolarization, and accelerated leakage of intracellular reducing sugars and proteins outward from the cytoplasm. In addition, dysfunction of the respiratory chain was induced after treatment with AgNP, which was supported by a decrease in intracellular ATP and inhibition of related dehydrogenases. This research indicates that AgNP could be a novel and efficient antibacterial agent to control C. sakazakii contamination in environments producing powdered infant formulas from milk., (Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Chronic Pseudomonas ear infections are difficult to treat, particularly in immunodeficient patients. Vinegar therapy is a time-tested measure for the treatment of these infections. It is inexpensive, simple, easy to administer, and very effective. However, some physicians are reluctant to use it in immunocompromised patients or in the setting of a perforated tympanic membrane. We describe our successful use of vinegar therapy in a 32-year-old man with both of these conditions. His Pseudomonas ear infection had persisted for more than 5 years despite conventional drug treatment. Eventually, we treated him with instillations of topical vinegar, and his infection cleared in 3 weeks.

Anti-microbial resistance burden and hazard associated with chemical treatment of infections demanded for new anti-microbial natural products. Marine associated microorganisms are the enormous source of bioactive compounds. In this study we have isolated 272 marine bacteria among them 136 (50%) were antagonistic to at least one of the four pathogenic strains Listeria monocytogenes, Vibrio cholerae, E. coli and S. aureus. Only two strains exhibited antibacterial activity against all four test strains, which were identified by 16S rDNA sequencing as Bacillus sp. DK1-SA11 and Vibrio sp. DK6-SH8. Marine isolate DK1-SA11 has potential to resist boiling temperature and pH 2-12. Furthermore cell free extract (CFE) inhibited all test organisms including superbug MRSA and pathogenic yeast Candida albicans. Marine isolate Bacillus sp. DK1-SA11 could be a potential combatant for the battle of drugs and bugs.

After analysis using HPLC and electronic ion spray mass spectroscopy, the purified siderophore produced by the marine-derived Aureobasidium pullulans HN6.2 was found to be fusigen. The purified desferric fusigen still had strong inhibition of growth of the pathogenic Vibrio anguillarum while the fusigen chelated by Fe3+ lost the ability to inhibit the growth of the pathogenic bacterium. The added iron in the medium repressed expression of the hydroxylase gene encoding ornithine N5-oxygenase that catalyzes the N5-hydroxylation of ornithine for the first step of siderophore biosynthesis in the yeast cells while expression of the hydroxylase gene in the yeast cells grown in the medium plus ornithine was enhanced.

Chloroform extract (CE) of Achyranthes ferruginea and N-trans-feruloyl-4-methyldopamine (1) showed remarkable antimicrobial activities against a wide range of bacteria and fungi. Both crude extract (CE) and compound 1 showed significant cytotoxicity of LC(50) at 16.21 microg/ml and 11.70 microg/ml, respectively.