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The increasing prevalence of fungal strains showing acquired resistance and multidrug resistance is an increasing therapeutic problem, especially in patients with a severely weakened immune system and undergoing chemotherapy. What is also extremely disturbing is the similarity of the resistance mechanisms of fungal cells and other eukaryotic cells, including human cells, which may contribute to the development of cross-resistance in fungi in response to substances used in e.g. anticancer treatment. An example of such a drug is methotrexate, which is pumped out of eukaryotic cells by ABC transmembrane transporters - in fungi, used to remove azoles from fungal cells. For this reason, the aim of the study was to analyze the expression levels of genes: ERG11, MDR1 and CDR1, potentially responsible for the occurrence of cross-resistance in Candida albicans and Candida parapsilosis as a result of fungal exposure to methotrexate (MTX). In vitro exposure of C. albicans and C. parapsilosis strains to methotrexate showed a high increase in resistance to fluconazole and a partial increase in resistance to voriconazole. Analysis of the expression of resistance genes showed varied responses of the tested strains depending on the species. In the case of C. albicans, an increase in the expression of the MDR1 gene was observed, and a decrease in ERG11 and CDR1. However, for C. parapsilosis there was an increase in the expression of the CDR1 gene and a decrease in ERG11 and MDR1. We noted the relationship between the level of resistance to voriconazole and the level of ERG11 gene expression in C. albicans. This indicates that this type of relationship is different for each species. Our research confirms that the mechanisms by which fungi acquire resistance and develop cross-resistance are highly complex and most likely involve several pathways simultaneously. The emergence of multidrug resistance may be related to the possibility of developing tolerance to antimycotics by fungi., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.)

In recent years, there has been a rapid increase in the incidence of Candida infections. The different species of the genus Candida vary in their virulence abilities and susceptibility to antifungal agents, depending on several external factors. The result of such modifications may be cross-resistance, which is understood as an acquired resistance to a certain antimicrobial agent after exposure to another drug. The aim of this study was to determine the possibility of cross-resistance between fluconazole, voriconazole, itraconazole, and methotrexate in Candida albicans and Meyerozyma guilliermondii (syn. Candida guilliermondii). Fieen strains of M. guilliermondii and eight strains of C. albicans, including the standard strains, were tested. For all strains, the minimum inhibitory concentrations (MICs) for fluconazole, voriconazole, and itraconazole were determined before and after stimulation with methotrexate. The median MICs in M. guilliermondii before and after stimulation were 9.333 and 64 mg/L (p =0.005) for fluconazole; 0.917 and 1.667 mg/L (p =0.001) for itraconazole, respectively. No significant change in MIC was observed for voriconazole. For C. albicans strains, the median MICs before and after stimulation were 0.917 and 64 mg/L (p =0.012) for fluconazole; 0.344 and 1.135 mg/L (p =0.018) for voriconazole, respectively. There was no significant change in MIC values for itraconazole. Thus, this study demonstrates the presence of cross-resistance between voriconazole, itraconazole, fluconazole, and methotrexate for the selected strains. Methotrexate exposure induces different responses when certain drugs are used for various species. Therefore, if a patient was previously exposed to methotrexate, there may be a higher risk of treatment failure with fluconazole than with other azoles such as voriconazole for fungemia caused by M. guilliermondii or itraconazole for C. albicans infection. [ABSTRACT FROM AUTHOR]

Microfungi occurring in surface water may represent an important health risk. Recreational water reservoirs are a potential reservoir of pathogenic fungi. The aim of the study was to assess the diversity of mycobiota in selected artificial bathing reservoirs with regard to its biosafety for the human population. The studies were conducted during the summer of 2016 in three research seasons (June (I), July and August (II), and September (III)), taking into account the various periods of recreational activities. Filamentous fungi were isolated from water samples collected at five different ponds utilized for recreation. From 162 water samples, 149 fungal taxa of filamentous fungi were identified: 140 were classified to species level and only nine to genus level. Aspergillus fumigatus was the dominant species. The highest species richness (S) was noted in June, with 93 fungal taxa (Menhinick's index from 2.65 to 4.49). Additionally, in season I, the highest diversity of fungal species was revealed (Simpson's diversity index from 0.83 to 0.99). The average number of CFU/1 mL sample ranged between 0.4 and 4.6 depending on the time of sampling and ponds. Of all the isolated species, 128 were clinically relevant (11 from RG-2 and 117 from RG-1), highlighting the need to introduce seasonal mycological monitoring of such reservoirs. [ABSTRACT FROM AUTHOR]

Introduction: Rapid increase of resistance of antropopathogenic fungi to routinely used antimycotic drugs forces researchers to search for new alternative methods of antifungal therapies. Among compounds investigated there are glucosinolates (GLS), whose antimycotic activity was proved against plant pathogens. Aim of the study: The aim of this study was to determine the value of minimal inhibition concentration (MIC) of GLS degradation products on yeast and yeast-like fungi isolated from human ontocenoses. Material and methods: Fungi were obtained from the collection of Department of Mycology, University of Warmia and Mazury in Olsztyn and isolated from the human respiratory system and digestive tract. GLS degradation products were originated from seeds of broccoli, small radish, mustard and cabbage and were prepared at the Department of Food Chemistry and Biodynamics of the Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences in Olsztyn using HPLC method. The MIC value was conducted with the disk-diffusion method. Results: Experiments showed that the strongest antifungal activity was demonstrated for GLS degradation products from broccoli (MIC reached 1.62±0.11 μmol/g), the lowest for GLS degradation products from small radish (MIC reached 5.87±4.08 μmol/g). Conclusions: The analysis of the inhibiting effect of GLS degradation products on the growth of fungi showed their possible usefulness for antimycotic therapy and prophylaxis. [ABSTRACT FROM AUTHOR]