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Background and Aim: Aspergillus flavus causes human and animal diseases through either inhalation of fungal spores or ingestion of mycotoxins as aflatoxins produced in human and animal feed as secondary metabolites. This study was aimed to detect the incidence of A. flavus and its aflatoxins in human sputum and milk powder samples and explore the efficacy of pure propolis (PP) and propolis nanoemulsion (PNE) as natural decontaminants against fungal growth and its released aflatoxins. Materials and Methods: A. flavus was isolated by mycological culture and identified macroscopically and microscopically. Coconut agar medium and thin-layer chromatography (TLC) were used to qualitatively detect aflatoxins in the isolated strains. Toxins were extracted from toxigenic strains by the fast extraction technique. The quantitative detection of toxin types was explored by high-performance liquid chromatography (HPLC). PNE was prepared by a novel method using natural components and characterized by Fourier-transform infrared spectroscopy, Zetasizer, and transmission electron microscopy. The effects of PP and PNE on A. flavus growth and its toxin were determined by the well-diffusion method and HPLC. Results: The mycological culture showed that 30.9% and 29.2% of sputum and milk powder samples were positive for A. flavus, respectively. TLC confirmed the production of 61.8% and 63.2% aflatoxin by the isolated strains in sputum and milk powder, respectively. PP and PNE showed antifungal activity on A. flavus growth with mean±standard error (SE) inhibition zones of 27.55±3.98 and 39.133±5.32 mm, respectively. HPLC revealed positive contamination of toxin extracts with AFB1, AFB2, and AFG2 at 0.57±0.026, 0.28±0.043, and 0.1±0.05 mg/L, respectively. After treatment with PP and PNE, a significant decrease in AFB1, AFB2, and AFG2 concentrations was observed. Conclusion: This study suggested using propolis and its nanoformulation as antifungal and antitoxins in human medicine and the food industry to increase the food safety level and stop food spoilage.

Background and Aim: Aspergillus fumigatus is a zoonotic fungus that causes several diseases in humans ranging from allergic reaction to fatal disseminated invasive infection, especially in immunocompromised patients. This study aimed to investigate the incidence of invasive A. fumigatus in patients admitted to the intensive care unit (ICU) of Assiut University Hospital, highlight the factors associated with their infection, and determine the antifungal effect of thyme nano-emulsion (TNE) and carvacrol nano-emulsion (CNE) on isolated A. fumigatus strains. Materials and Methods: Mycological culture method and scanning electron microscopy (SEM) were used in the identification of A. fumigatus in 630 blood samples collected from 210 patients. TNE and CNE at five concentrations (1%, 2%, 4%, 6%, and 8%) and average sizes of 90.3 and 75.6 nm, respectively, were characterized by transmission electron microscopy. Their effect on A. fumigatus isolate growth was evaluated by the well-diffusion method and SEM, which was used for the detection of the degenerative effect of A. fumigatus ultrastructure. Results: A. fumigatus was detected in 54 of 210 (25.7%) patients in the ICU. Advanced age and chronic diseases were considered important risk factors for invasive aspergillosis, especially in patients with more than 1 clinical disease. TNE and CNE showed an inhibitory effect on A. fumigatus isolates, which significantly increased with high concentrations. The respective values for TNE at concentrations of 6% and 8% were 6±0.41 mm and 15±0.67 mm. CNE completely inhibited A. fumigatus growth at concentrations of 4%, 6%, and 8%, while mean inhibition zones of 22±0.68 mm and 30±0.32 mm appeared at concentrations of 1% and 2%. SEM demonstrated degenerative changes in A. fumigatus structure. Conclusion: TNE and CNE can be used in bioactive treatments against A. fumigatus, and additional studies are required to determine the safe and effective doses and best method for application in human and veterinary medicine.

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Food safety is a worldwide health goal so foodborne diseases are a main health concern. A total 150 of dairy products samples (locally made yoghurt, ice cream and Talaga cheese) (50 for each type) were examined for E.coli O157:H7 detection and PCR confirmation using fliCH7 gene. E. coli O157:H7 was detected at 18%, 4%, 8% respectively, in samples. The isolates showed broad antibiotic resistance against vancomycin (84.6%), penicillin G (76.9%), cloxacillin (69.2%) and tetracycline (61.5%). Because of increasing number of microorganisms that are resistant to multiple antibiotics causing continuing economic losses in dairy manufacturing, there is an urgent need for development of alternative, cost-effective, and efficient antimicrobial agents to overcome antimicrobial resistance. Here, silver nanoparticle (AgNPs) solution was prepared, identified by transmission electron microscopy (TEM) with an average size 26.5 nm and examined for bactericidal activity against E. coli O157:H7 by using well diffusion assay. The mean inhibition zones of 25 and 50 µg/ml concentrations of Ag-NPs were 15.0±1.2 and 20.9±1.4 mm, respectively. In addition, the statistical analysis showed highly significant differences in the bactericidal effect of different Ag-NPs concentrations on E. coli O157:H7 strains. Bacterial sensitivity to nanoparticles is a key factor in manufacture, so nanoparticles were considered suitable for long life application in food packaging and food safety.

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