The impact of silver and chitosan nanoparticles on A. fumigatus isolates from Ras cheese and sputum of respiratory patients

Abstract

This work was designed to study the incidence of Aspergillus fumigatus (A. fumigatus) in Ras cheese sold in different markets at Sohag city, Egypt and also in sputum samples of respiratory diseases patients admitted to Sohag University Hospital, as well as study the effect of silver (SNPs) and chitosan (CNPs) nanoparticles against the A. fumigatus isolates. Potato dextrose agar (PDA) was used for mycological culture of samples and the antifungal effect of nanoparticles (with different concentrations) using well diffusion method. High resolution transmission electron microscope (HRTEM) was used for detection of nanoparticles size, and scanning electron microscope (SEM) was used for investigation of nanoparticles effect on A.fumigatus morphology. The isolation rate of A. fumigatus was 22.11 % (21/95), 32.17 % (37/115) from Ras cheese and sputum samples, respectively. SNPs had inhibitory effect at concentrations 1 and 2 µg/ml, and complete growth inhibition with concentrations 4, 8, and 16 µg/ ml. While CNPs had no effect in concentrations 1 and 2 µg/ ml, but at concentrations 4, 8 and 16 µg/ ml represented inhibitory effect with mean inhibition zones 5±0.21, 9±0.41 mm and 11 ±0.77mm, respectively. SNPs and CNPs by SEM patently damaged the A. fumigatus cell structure. Using nanoparticles against A. fumigatus from food and human sources is important to stop food spoilage and protect human health. So, further studies are necessary for the investigation of suitable application methods, and the expected hazards which may occur after nanoparticles usage.

Keywords

• ras cheese
• a. fumigatus
• respiratory patients
• silver nanoparticles
• chitosan nanoparticles
• scanning electron microscope