Echinocandin Drugs Induce Differential Effects in Cytokinesis Progression and Cell Integrity

Fission yeast contains three essential β(1,3)-D-glucan synthases (GSs), Bgs1, Bgs3, and Bgs4, with non-overlapping roles in cell integrity and morphogenesis. Only the bgs4+ mutants pbr1-8 and pbr1-6 exhibit resistance to GS inhibitors, even in the presence of the wild-type (WT) sequences of bgs1+ and bgs3+. Thus, Bgs1 and Bgs3 functions seem to be unaffected by those GS inhibitors. To learn more about echinocandins’ mechanism of action and resistance, cytokinesis progression and cell death were examined by time-lapse fluorescence microscopy in WT and pbr1-8 cells at the start of treatment with sublethal and lethal concentrations of anidulafungin, caspofungin, and micafungin. In WT, sublethal concentrations of the three drugs caused abundant cell death that was either suppressed (anidulafungin and micafungin) or greatly reduced (caspofungin) in pbr1-8 cells. Interestingly, the lethal concentrations induced differential phenotypes depending on the echinocandin used. Anidulafungin and caspofungin were mostly fungistatic, heavily impairing cytokinesis progression in both WT and pbr1-8. As with sublethal concentrations, lethal concentrations of micafungin were primarily fungicidal in WT cells, causing cell lysis without impairing cytokinesis. The lytic phenotype was suppressed again in pbr1-8 cells. Our results suggest that micafungin always exerts its fungicidal effect by solely inhibiting Bgs4. In contrast, lethal concentrations of anidulafungin and caspofungin cause an early cytokinesis arrest, probably by the combined inhibition of several GSs.

Determination of antimicrobial and fungicidal properties of experimental disinfectant "Sukhodez"

The results of the study of antimicrobial and fungicidal properties of the experimental preparation “Sukhodez” against microorganisms E. coli, Salmonella enteritidis, Staphylococcus aureus and fungi Candida albicans in the laboratory are presented. The aim of the research. To study the antimicrobial and fungicidal properties of powdered disinfectant and analyze the prospects for its further use in a set of anti-epizootic measures in particular in poultry farms. Materials and methods. The research was conducted during 2021 at the Department of Veterinary Examination, Microbiology, Zoohygiene and Safety and Quality of Animal Products of the Faculty of Veterinary Medicine of Sumy National Agrarian University. Evaluation of bactericidal properties of the experimental agent “Sukhodez” was determined on museum strains of E. coli ATCC 25922, Salmonella enteritidis ATCC 13076 and Staphylococcus aureus ATCC 6538, fungicidal properties were studied on fungi Candida albicans. All cultures were standardized to 109 CFU / cm3. Results. It is established that as a result of the conducted researches at studying preparation “Sukhodez” antimicrobic properties, it had high efficiency concerning action on strains of both gram-positive and gram-negative bacteria. It had a detrimental effect on bacteria when applied to concrete at an exposure of 1 hour with a rate of 75 mg per 1 m2, and had the same effect as when applied to a wooden surface, where it expressed antimicrobial action at a rate of 50 mg/m2 after 4 hours. When determining the fungicidal properties, it was found that when exposed to 5 hours, the preparation “Sukhodez” had an effect on study contaminated objects with a rate of 50 mg/m2, and with a rate of 75 mg/m2 inhibited the growth of fungi for 1 hour. Conclusions. It was found that the most sensitive to the preparation “Sukhodez” were the culture of Salmonella enteritidis – at a rate of 25 g / m2 and action on concrete and wooden surfaces, the disinfectant inhibited the growth of the culture when exposed to 5 hours, and at a rate of 50 g / m2 – for 2 years. Staphylococcus aureus was the most stable bacterial culture, so at a rate of 50 g / m2 on concrete and wood surfaces, bacterial growth was inhibited for 4 and 5 hours, respectively. At the same time, in the study of fungicidal properties, “Sukhodez” showed a fungicidal effect on Candida albicans when applied to a concrete surface at a rate of 50 mg / m2 for 3 hours, when applied to a wooden surface – for 4 hours. In general, at a rate of 75 g / m2, “Sukhodez” has an instant bactericidal and fungicidal effect on bacteria and fungi applied to concrete and wooden surfaces

Edible Chitosan/Propolis Coatings and Their Effect on Ripening, Development of Aspergillus flavus, and Sensory Quality in Fig Fruit, during Controlled Storage

Biodegradable alternatives for the control of Aspergillus flavus in fig fruit were tested with the application of coatings based on chitosan (CS) and propolis (P). To potentiate the fungicidal effect, nanoparticles of these two (CSNPs and PNPs) were also considered. The objectives of this research were to evaluate the effect of different formulations on: (a) the ripening process of the fig, (b) the incidence of A. flavus and the production of aflatoxins, and (c) the acceptance of the treated fruit by a panel. The nanostructured coatings did not influence the ripening process of the fruit during the 12 days of storage, however, the antioxidant activity increased by approximately 30% with the coating CS + PNPs + P. The figs treated with CS + CSNPs + PNPs + P, inhibited the growth of the fungus by about 20% to 30% under laboratory and semi-commercial conditions. For all treatments, the aflatoxin production was lower than 20 ppb compared to the control with values of c.a. 250 ppb. The sensory quality was acceptable among the panel. The edible coatings can be a non-toxic alternative for post-harvest preservation and the consumption of fig fruit. The next step will be its inclusion and evaluation at a commercial level in packing houses.

The effectiveness of using biological preparations in the production technology for seed material of potatoes

An integrated plant protection system must focus on the biologization of this process. Used phytohormones and phytofungicides have a biostimulating and fungicidal effect on potato plants. The biological products used to one degree or another increase the adaptogenic capabilities of plants. Biological preparations have provided a high level of immunity of potato plants to major diseases. The fungicidal properties of the preparations were well appeared. No increase in infection or spread was observed in experiments using biofungicides. To a greater extent, the preparations acted as prophylactic ones, preventing the penetration of the phytopathogen into plants. At the same time, there is a long period of suppression of its development, the formation of resistance to late blight. The immunostimulating effect of Zircon and Epin extra in relation to late blight is found to a lesser extent in comparison with the Trichodermin, Rizoplan and Baktofit biofungicides. The fungicidal action of these preparations proved to be highly effective.

Efficient Reduction of Food Related Mould Spores on Surfaces by Hydrogen Peroxide Mist

The aim of the study was to evaluate the fungicidal effect of a H2O2 mist generating system for disinfection of spores of six food-related moulds (Alternaria alternata, Aspergillus flavus, Geotrichum candidum, Mucor plumbeus, Paecilomyces variotii, and Penicillium solitum) dried on stainless steel. Exposure to H2O2 mist for 2 or 4 h lead to >3 log reduction in mould spores in the majority of the tests. The presence of the soils 2% skim milk or 3% BSA did not significantly alter the fungicidal effect, while the presence of raw meat juice had an adverse fungicidal effect against Penicillium and Mucor in two out of three tests. Fungicidal suspension tests with liquid H2O2 confirmed the effectiveness of H2O2 on reducing the mould spores. Both the surface test and the suspension test indicated that P. variotii is more resistant to H2O2 compared to the other moulds tested. The study shows the efficiency of H2O2 mist on reducing food-related mould spores on surfaces.