Maryam Alnoman

Clostridium perfringens is a spore-forming bacterium that causes food poisoning. Given the high heat resistance of its spores, natural antimicrobial agents are considered as alternatives to thermal processing strategies to inactivate or eliminate such spores from food products. A high chitosan concentration (0.2%) can effectively inhibit the growth of C. perfringens spores in cooked chicken meat, whereas nisin cannot (even at concentrations four times higher than those permitted: 250 μM). However, nisin is an effective inhibitor when in combination with other preservatives. Therefore, we evaluated the inhibitory effects of a chitosan–nisin combination on the germination, outgrowth, and vegetative growth of C. perfringens spores in laboratory medium and chicken meat. Among many tested concentration combinations, a 0.025% chitosan and 0.075% nisin mixture was found to be the most effective for inhibiting spore germination and outgrowth in laboratory medium. Furthermore, a mixture of chitosan–nisin, at 0.025% each, blocked the vegetative growth of C. perfringens spores. However, four-times higher concentrations of chitosan–nisin (0.1% each) were required to effectively inhibit C. perfringens spore germination in chicken meat. Collectively, our results suggest that the combination of chitosan and nisin can be considered as an alternative approach to control C. perfringens spore germination in meat products.

Background and Objectives: The relationship between hepatitis C virus (HCV) infection and melanoma remains poorly understood. This study aimed to investigate the association between HCV and melanoma, assess outcomes in patients with both conditions, and explore potential molecular mechanisms connecting the two diseases. Materials and Methods: We conducted a retrospective cohort study of 142 melanoma patients, including 29 with HCV-related cirrhosis, and analyzed their clinical outcomes. For external validation, we used the TriNetX Global Collaborative Network database, comprising 219,960 propensity-matched patients per group. An in silico analysis was performed to identify the molecular pathways linking HCV and melanoma. Results: In the retrospective cohort, HCV-positive melanoma patients showed an increased risk of early relapse (41.4% vs. 18.6%, p = 0.014), recurrence (65.5% vs. 39.8%, p = 0.020), and mortality (65.5% vs. 23.0%, p < 0.001) compared to HCV-negative patients. TriNetX data analysis revealed that HCV-positive patients had a 53% lower risk of developing melanoma (RR = 0.470, 95% CI: 0.443–0.498, p < 0.001). However, HCV-positive melanoma patients had higher all-cause mortality (HR = 1.360, 95% CI: 1.189–1.556, p < 0.001). An in silico analysis identified key molecular players, including IL-6 and CTLA4, in the HCV-melanoma network. Conclusions: While HCV infection may be associated with a lower risk of melanoma development, HCV-positive patients who develop melanoma have poorer outcomes. The identified molecular pathways provide potential targets for future research and therapeutic interventions.

In this study, we investigated the spore germination phenotype of Clostridium perfringens strains isolated from diarrheic animals (animal strains). The transcripts of germination-specific genes and their protein products were also measured. Our study found the following results: (i) animal strains spores germinated at a slower rate with AK (mixture of L-asparagine and KCl), L-cysteine, or L-lysine, but the extent of germination varied based on strains and germinants used; (ii) none of the amino acids (excluding L-cysteine and L-lysine) were identified as a universal germinant for spores of animal strains; (iii) animal strain spores germinated better at a pH range of 6.0–7.0; (iv) all tested germination-specific genes were expressed in animal strains; the levels of expression of major germinant receptor gene (gerKC) were higher and the cortex hydrolysis machinery genes (cspB and sleC) were lower in animal strains, compared to the food poisoning strain SM101; and (v) the levels of CspB and SleC were significantly lower in spores of animal strains compared to strain SM101, suggesting that these animal strains lack an efficient spore cortex hydrolysis machinery. In summary, our findings suggest that the poor or slow spore germination in C. perfringens animal strains might be due to incomplete spore cortex hydrolysis.

Aim/Background: Oxidative and inflammatory damage induced by bacterial infections has been attributed as a more concerning health issue raised by health professionals and researchers due to large antibiotic drug resistance. Natural products and their derived medicines play an immense role in fighting pathogenic micro-organisms. Considering these factors, the study is aimed at exploring the biological effect of andrographolide against gram-positive and negative bacterial strains that induce oxidative and inflammatory onsets using in silico approaches. Materials and Methods: In silico docking analysis was conducted using AutoDock Vina to determine the biological interactivity of andrographolide with proteins (catalase (CAT), tumor necrosis factor (TNF-α), and cytochrome P450 VDH mutant T107A with bound Vitamin D₃) involved in pathogenesis caused by bacterial infection. Furthermore, absorption, distribution, metabolism and excretion (ADME) analysis was performed to evaluate the pharmacokinetic behavior of andrographolide by assessing several parameters such as lipophilicity, skin permeability, GI absorption, blood-brain barrier (BBB) permeability. Results: The results of the study showed that andrographolide exhibited significant interaction with TNF-α with amino acids such as GLN B: 27, ILE B: 136, and ASP B: 45 for site 1 and ASN D: 30, ARG C: 31, and ARG C: 82 for site 2. However, the effect of andrographolide was found to be comparable with that of other proteins. In ADME analysis, the boiled egg plot represents the andrographolide that exists in the white region, which represents a good distribution of andrographolide, while lipophilicity in the form of the consensus logP was found to be 2.3 with high GI-absorption and no BBB permeability. Conclusion: The study concludes that andrographolide can be a promising agent against oxidative and inflammatory stress induced by bacterial onsets and may reduce the vitality of several gram-positive and gram-negative bacterial strains.

In this study, bimetallic nanoparticles (NPs) of silver (Ag) and zinc oxide (ZnO) were synthesized using Leptadenia pyrotechnica leaf extract for the first time. Monometallic NPs were also obtained for comparison. The characterization of the prepared NPs was carried out using various techniques, including UV-Visible spectroscopy (UV-Vis), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The latter confirmed the crystalline nature and diameter of the monometallic and bimetallic NPs of Ag and ZnO. The SEM images of the prepared NPs revealed their different shapes. The biological activities of the NPs were evaluated concerning their antibacterial, antioxidant, and cytotoxic properties. The antibacterial activities were measured using the time-killing method. The results demonstrated that both the monometallic and bimetallic NPs inhibited the growth of Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. The antioxidant activities of the NPs were evaluated using the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay and their cytotoxicity was checked using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The results indicated that the controlled quantity of the monometallic and bimetallic NPs did not affect the viability of the cells. However, the decreased cell (L-929) viability suggested that the NPs could have anticancer properties. Furthermore, the photocatalytic degradation of methyl violet and 4-nitrophenol was investigated using the prepared Ag/ZnO NPs, examining the factors affecting the degradation process and conducting a kinetic and thermodynamic study. The prepared Ag/ZnO NPs demonstrated good photocatalytic degradation (88.9%) of the methyl violet (rate constant of 0.0183 min⁻¹) in comparison to 4-nitrophenol (NPh), with a degradation rate of 81.37% and 0.0172 min⁻¹, respectively. Overall, the bimetallic NPs showed superior antibacterial, antioxidant, cytotoxic, and photocatalytic properties compared to the monometallic NPs of Ag and ZnO.

Fusarium solani, the causative agent of root rot disease is one of the major constraints of faba bean (Vicia faba L.) yield worldwide. Essential oils have become excellent plant growth stimulators besides their antifungal properties. Foeniculum vulgare Mill. (fennel) is a familiar medicinal plant that has inhibitory effects against phytopathogenic fungi. Herein, different concentrations of fennel seed essential oil (FSEO) (12.5, 25, 50, 100, 200 and 400 μL/mL) were examined against F. solani KHA10 (accession number MW444555) isolated from rotted roots of faba bean in vitro and in vivo. The chemical composition of FSEO, through gas chromatography/mass spectroscopy, revealed 10 major compounds. In vitro, FSEO inhibited F. solani with a minimum inhibitory concentration (MIC) of 25 µL/mL. In vivo, FSEO suppressed Fusarium root rot disease in Vicia faba L. by decreasing the disease severity (61.2%) and disease incidence (50%), and acted as protective agent (32.5%) of Vicia faba L. Improvements in morphological and biochemical parameters were recorded in FSEO-treated faba seeds. Moreover, the expression level of the defense-related genes defensin and chitinase was noticeably enhanced in treated plants. This study suggested using FSEO as a promising antifungal agent against F. solani not only to control root rot disease but also to enhance plant growth and activate plant defense.

An endophytic strain of Streptomyces antimycoticus L-1 was isolated from healthy medicinal plant leaves of Mentha longifolia L. and used for the green synthesis of silver nanoparticles (Ag-NPs), through the use of secreted enzymes and proteins. UV–vis spectroscopy, Fourier-transform infrared (FT-IR), transmission electron microscopy (TEM), X-ray diffraction (XRD), and dynamic light scattering (DLS) analyses of the Ag-NPs were carried out. The XRD, TEM, and FT-IR analysis results demonstrated the successful biosynthesis of crystalline, spherical Ag-NPs with a particle size of 13–40 nm. Further, the stability of the Ag-NPs was assessed by detecting the surface Plasmon resonance (SPR) at 415 nm for one month or by measuring the NPs surface charge (−19.2 mV) by zeta potential analysis (ζ). The green-synthesized Ag-NPs exhibited broad-spectrum antibacterial activity at different concentrations (6.25–100 ppm) against the pathogens Staphylococcus aureus, Bacillus subtilis Pseudomonas aeruginosa, Escherichia coli, and Salmonella typhimurium with a clear inhibition zone ranging from (9.5 ± 0.4) nm to (21.7 ± 1.0) mm. Furthermore, the green-synthesized Ag-NPs displayed high efficacy against the Caco-2 cancerous cell line (the half maximal inhibitory concentration (IC₅₀) = 5.7 ± 0.2 ppm). With respect to antibacterial and in-vitro cytotoxicity analyses, the Ag-NPs concentration of 100 ppm was selected as a safe dose for loading onto cotton fabrics. The scanning electron microscopy connected with energy-dispersive X-ray spectroscopy (SEM-EDX) for the nano-finished fabrics showed the distribution of Ag-NPs as 2% of the total fabric elements. Moreover, the nano-finished fabrics exhibited more activity against pathogenic Gram-positive and Gram-negative bacteria, even after 10 washing cycles, indicating the stability of the treated fabrics.