Assessing the efficacy of zinc oxide nanoparticles against Penicillium expansum by automated turbidimetric analysis

Abstract

Public concerns about food safety have triggered a worldwide implementation of new legislations aimed at banning many of the most popular food conventional antifungal treatments. There is therefore an urgent need to identify novel and safer solutions to prevent fungal contamination of food. The antifungal effect of zinc oxide nanoparticles (ZnO NPs) against the postharvest pathogenic fungus Penicillium expansum has been investigated in this study. An automated turbidimetric assay, with a standard 96-well microplate, has been developed and optimised regarding the selection of the inoculum size in order to collect sequential optical density measurements. Data were processed by the updated version of the Lambert Pearson model to estimate the minimum inhibitory concentration and the non-inhibitory concentration values which were found to be 9.8 and 1.8 mM (i.e. 798 and 147 ppm), respectively. The current results show that turbidimetry is a reliable technique for assessing the antifungal activity of metal nanoparticles and that zinc oxide (ZnO) is an effective fungicide which can be potentially used to control food safety.

<p>Antifungal Activity of ZnO Nanoparticles and Nystatin and Downregulation of SAP1-3 Genes Expression in Fluconazole-Resistant <em>Candida albicans</em> Isolates from Vulvovaginal Candidiasis</p>

“…17,27 We used sub-MIC (3±1.7µg/mL) concentrations of ZnO nanoparticles and Nystatin to inhibit the expression of SAP1-3 genes. The results revealed that both ZnO and Nystatin decreased the SAP1-3 genes expression in all isolates that is in accordance with the findings of Cho et al 10,[28][29][30] This finding shows that ZnO nanoparticles 5±1.3µg/mL and Nystatin 3±1.3µg/mL Figure 5 Comparison of the expression of SAP1-3 of VVC C. albicans isolates with 3±1.7µg/mL concentrations of ZnO-nanoparticles and Nystatin compared to the calibrated gene in the control group (Value of the nonadjacent samples was zero). The ACT1 gene was used as an internal control (P<0.05).…”

“…3 The yeasts were first identified according to their morphological characteristics using several phenotypic techniques such as production of germ tube in human serum, culture on CHROMagar Candida (Chromagar, France), and Cornmeal agar (Sharlo, USA), containing Tween 80. 10 After identification of primary morphology, DNA extraction was performed using the Phenol-chloroform-isoamyl alcohol method. DNA was amplified using the ITS1 (5ʹ-TCC GTA GGT GAA CCT GCG G-3ʹ) and ITS4 (5ʹ-TCC TCC GCT TAT TGA TAT GC-3ʹ) primers, which were used for PCR amplification of the ITS1-5.8S-ITS2 rDNA region.…”

“…6 Also, mutations in the ERG11 gene exist and contribute to resistance in about 65% of Fluconazole-resistant candida species. 6,10 Among the Fluconazole-resistant isolates, mutations in the ERG11 gene among the candida species are responsible for significant differences in their susceptibility to Fluconazole. 11 Secreted Aspartyl Proteinases (SAP) are considered as a potential factor that may affect the virulence of this yeast.…”

Application of ZnO-nanoparticles to manage Rhizopus soft rot of sweet potato and prolong shelf-life

“…By contrast, the application of ZnO concentrations did not reveal antifungal activities against R. stolonifer. Our results were in accordance with those of others who had demonstrated the fungicidal efficacy of ZnO-NPs against post-harvest pathogens, including Penicillium expansum Yehia and Ahmed, 2013;Sardella et al, 2018) Fusarium oxysporum (Yehia and Ahmed, 2013) and Botrytis cinerea . Also, Jamdagni et al (2018a) stated that green-synthesized ZnO-NPs had a good antifungal activity against Alternaria alternata, Aspergillus niger, Botrytis cinerea, Fusarium oxysporum and Penicillium expansum showing a minimum inhibitory concentration (MIC) of 64, 16, 128, 64 and 128 µg L -1 , respectively.…”

Tackling Multidrug Resistance in Streptococci – From Novel Biotherapeutic Strategies to Nanomedicines

“…Copper nanoparticles have also been used as antimicrobial against a wide range of microorganisms including bacteria, fungi, and even algae ( Hou et al, 2018 ; Sardella et al, 2018 ). As for AgNPs, the size is related to CuNP activity due to the dramatic increase of the surface/volume ratio, which promote the generation of ROS that trigger cell damage according, such as oxidation of proteins, cleavage of DNA/RNA molecules or lipid peroxidation in membranes ( Shaikh et al, 2019 ).…”