This study utilized Aspergillus flavus to produce selenium nanoparticles (Se-NPs) in an environmentally friendly and ecologically sustainable manner, targeting several medicinal applications. These biosynthesized Se-NPs were meticulously characterized using X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, transmission electron microscope (TEM), and UV–visible spectroscopy (UV), revealing their spherical shape and size ranging between 28 and 78 nm. We conducted further testing of Se-NPs to evaluate their potential for biological applications, including antiviral, anticancer, antibacterial, antioxidant, and antibiofilm activities. The results indicate that biosynthesized Se-NPs could be effective against various pathogens, including Salmonella typhimurium (ATCC 14028), Bacillus pumilus (ATCC 14884), Staphylococcus aureus (ATCC 6538), Clostridium sporogenes (ATCC 19404), Escherichia coli (ATCC 8739), and Bacillus subtilis (ATCC 6633). Additionally, the biosynthesized Se-NPs exhibited anticancer activity against three cell lines: pancreatic carcinoma (PANC1), cervical cancer (Hela), and colorectal adenocarcinoma (Caco-2), with IC50 values of 177, 208, and 216 μg/mL, respectively. The nanoparticles demonstrated antiviral activity against HSV-1 and HAV, achieving inhibition rates of 66.4% and 15.1%, respectively, at the maximum non-toxic concentration, while also displaying antibiofilm and antioxidant properties. In conclusion, the biosynthesized Se-NPs by A. flavus present a promising avenue for various biomedical applications with safe usage.

Background and Objectives: Urinary tract infections [UTIs] are considered the third most known risk of infection in human health around the world. There is increasing appreciation for the pathogenicity of Gram-positive and Gram-negative strains in UTIs, aside from fungal infection, as they have numerous virulence factors. Materials and Methods: In this study, fifty urine samples were collected from patients suffering from UTI. Among the isolates of UTI microbes, six isolates were described as MDR isolates after an antibiotic susceptibility test carried out using ten different antibiotics. An alternative treatment for microbial elimination involved the use of biosynthesized silver nanoparticles (AgNPs) derived from Solanum lycopersicum [S. cumin]. Results: The sizes and shapes of AgNPs were characterized through TEM imaging, which showed spherical particles in a size range of 35–80 nm, of which the average size was 53 nm. Additionally, the silver nanoparticles (AgNPs) demonstrated inhibitory activity against Staphylococcus aureus (OR648079), exhibiting a 31 mm zone of inhibition at a minimum inhibitory concentration (MIC) of 4 mg/mL and a minimum bactericidal concentration (MBC) of 8 mg/mL. This was followed by Aspergillus niger (OR648075), which showed a 30 mm inhibition zone at an MIC of 16 mg/mL and a minimum fungicidal concentration (MFC) of 32 mg/mL. Then, Enterococcus faecalis (OR648078), Klebsiella pneumoniae (OR648081), and Acinetobacter baumannii (OR648080) each displayed a 29 mm zone of inhibition at an MIC of 8 mg/mL and an MBC of 16 mg/mL. The least inhibition was observed against Candida auris (OR648076), with a 25 mm inhibition zone at an MIC of 16 mg/mL and an MFC of 32 mg/mL. Furthermore, AgNPs at different concentrations removed DPPH and H₂O₂ at an IC50 value of 13.54 μg/mL. Also, AgNPs at 3 mg/mL showed remarkable DNA fragmentation in all bacterial strains except Enterococcus faecalis. The phytochemical analysis showed the presence of different active organic components in the plant extract, which concluded that rutin was 88.3 mg/g, garlic acid was 70.4 mg/g, and tannic acid was 23.7 mg/g. Finally, AgNPs concentrations in the range of 3–6 mg/mL showed decreased expression of two of the fundamental genes necessary for biofilm formation within Staphylococcus aureus, fnbA (6 folds), and Cna (12.5 folds) when compared with the RecA gene, which decreased by one-fold when compared with the control sample. These two genes were submitted with NCBI accession numbers [OR682119] and [OR682118], respectively. Conclusions: The findings from this study indicate that biosynthesized AgNPs from Solanum lycopersicum exhibit promising antimicrobial and antioxidant properties against UTI pathogens, including strains resistant to multiple antibiotics. This suggests their potential as an effective alternative treatment for UTIs. Further research is warranted to fully understand the mechanisms of action and to explore the therapeutic applications of these nanoparticles in combating UTIs.

The hepatitis C virus (HCV) is a major global health challenge and a leading cause of morbidity and mortality. Many direct-acting antivirals (DAAs) target essential macromolecules involved in the virus’ life cycle. Although such DAAs achieve great success in reducing the viral load in genotype 1 infections, other genotypes demonstrate different levels of response. This study focused on mutation sites associated with patients with genotype 4a infections that failed to respond to treatment with sofosbuvir. The genotyping of HCV samples from patients with virological failure, and responder patients, was conducted using Geno2Pheno webserver-based full NS5B sequences. We constructed 3D structural models for all the samples and used structural analysis to investigate the effect of amino acid substitution on the observed resistance to SOF-based treatment, and the docking of sofosbuvir into the active sites of the 10 models was performed. Finally, 10 molecular dynamic (MD) simulation experiments were conducted to compare the stability of the 3D models of the resistant samples against the stability of the 3D models of the responder samples. The results highlighted the presence of HCV subtype 4a in all ten samples; in addition, an amino acid (aa) substitution in the palm region may hinder HCV polymerase activity. In this study, we provide evidence that a mutation in the NS5B gene that induces resistance to sofosbuvir in patients with the S282T/C/R mutant virus is present in the Egyptian population. Overall, the docking and MD results support our findings and highlight the significant impact of the identified mutations on the resistance of HCV NS5B RNA-dependent RNA polymerase to direct-acting antivirals (DAAs).

Acne vulgaris (AV) is a chronic inflammatory disease of the pilosebaceous follicles that affects nearly 90% of teenagers; half of them continue to experience symptoms as adults. There have been several reports of monomorphic acneiform eruptions in patients treated with intramuscular cobalamin injections. The eruptions resolved after the cessation of the therapy. Cyanocobalamin, pyridoxine (B6), and riboflavin (B2) have been reported to exacerbate existing acne. Moreover, it was reported that in acne patients, the serum level of vitamin B12 was significantly decreased after treatment, but no explanation was given. We propose a vitamin B12-mediated bacterial mechanism for acne pathogenesis on the evidence mentioned above. One hundred twenty AV patients were recruited. Our results proved that vitamin B12 was involved in the pathogenesis of AV; in vivo, it proved that AV patients had significantly higher serum levels of the vitamin than controls and showed a positive correlation to the disease duration and severity. In vitro, it proved that vitamin B12 supplementation to p. acnes cultures significantly raised the porphyrins produced in these cultures when compared to the non-supplemented ones. It also proved that this shift in the metabolism is secondary to inhibition of the cbiL gene of the vitamin B12 synthesis in the bacteria; as porphyrins and vitamin B12 share the same precursors, vitamin B12 does has a role in either elicitation or aggravation of AV.

Biofilm‐associated infections account for a majority of chronic bacterial diseases. These infections also present a therapeutic challenge due to their intrinsic tolerance to conventional antibiotics. Carbon dots (CDs) have emerged as a versatile nanoplatform with the potential to combat these resilient structures. This review critically evaluates the burgeoning field of CD‐based antibiofilm agents. We move beyond a catalog of studies to analyze how the physicochemical properties of CDs dictate their mechanisms of action against a panel of microorganisms. The antibiofilm activity of CDs is multi‐sided, stemming from their ability to (1) electrostatically interact with and disrupt the biofilm matrix and bacterial cell envelopes, (2) penetrate deep into biofilms due to their ultrasmall size, (3) generate ROS that degrade the extracellular polymeric substance (EPS) and kill embedded cells, and (4) downregulate key genes involved in quorum sensing and biofilm formation. An analysis of the literature reveals an efficacy bias towards Gram‐positive bacteria, highlighting the barrier posed by the outer membrane of Gram‐negative pathogens. We dissect how synthetic strategies and surface passivation techniques (e.g., with cationic polymers, lysozyme, or targeting ligands) are being deployed to overcome these challenges. While CDs represent a frontier in antibiofilm therapy, the field faces hurdles, including a lack of standardized testing protocols, limited in vivo validation, and unresolved questions about toxicity. This review identifies these critical gaps and proposes future research directions focused on the rational design of next‐generation CDs with enhanced specificity, potency, and translational potential for treating recalcitrant biofilm infections.