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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. [ABSTRACT FROM AUTHOR]

Interactions between C. albicans and the microbiota play an important role in maintaining the balance between commensal and pathogenic organisms. Although the exact role of bacteria in reducing the pathogenicity of yeast remains poorly understood, a few examples have been documented so far: probiotics administration effectively reduces the formation of biofilm and bacterial metabolites inhibit the formation of hyphae. The aim of the study was to analyze C. albicans virulence levels based on the changes in the morphological structure and enzymatic profile in experimental cultures mixed with Escherichia coli. Viable cell abundance, cell pleomorphism and enzymatic profile were analyzed in single and mixed cultures (C. albicans + E. coli). The microscope analysis showed a large decrease in the number of viable C. albicans cells in mixed cultures with E. coli from 485.3±132.1 immediately after the establishment of the culture to 238.1±71.2 after an hour of incubation and 24.4±5.4 after 24 h. The length of C. albicans cells differed significantly between the single-species cultures and the mixed cultures for 24 h. Our present findings indicate a significant reduction in the secretion of several enzymes by fungi following contact with E. coli , including acid phosphatase, N-acetyl-β-glucosaminidase, naphthol-AS-BI-phosphohydrolase and leucine arylamidase. The interactions between fungi and bacteria appear to be extremely complex. On the one hand, during C. albicans with E. coli co-incubation, the bacteria stimulated the elongation of yeast cells, leading to the formation of a filamentous form; however, the number of yeast cells and their enzymatic activity decreased significantly. Therefore, it can be concluded that while E. coli stimulates some pathogenic properties, e.g. cell elongation, it also inhibits other virulence features, e.g. enzymatic activity of C. albicans. [ABSTRACT FROM AUTHOR]

Migratory water birds, including the Mallard (Anas platyrhynchos) – one of the most abundant waterfowl species – are involved in the dispersal of microfungi. This study was undertaken to collect data on the possible differences in fungal biota between mallards in urban and non-urban areas. In total, 53 species of microfungi were found in samples taken from the bill cavity and the cloaca. Among them, 19% are pathogens of humans, including the most common fungus, Candida albicans (18.0% of all isolates). Mallards living in proximity to humans were colonised with a higher number of fungal species than were birds living in non-urban areas. This might be the result of conditions that are favourable for microfungi in cities. The differences between the urban and non-urban environments are responsible for the higher levels of similarity in the species structure of the fungi found in the bill cavity and the cloaca within the same environment rather than in the same ontocenoses from different sites. [ABSTRACT FROM AUTHOR]

Although previous cases of ethyl alcohol production by microorganisms present in the intestines, referred to as auto-brewery syndrome (ABS), have been reported, a recent case in our practice was characterized by the production of alcohol in the oral cavity. Our research indicates that legally significant levels of ethyl alcohol can be detected in exhaled air in cases where there has been no alcohol consumption but where the subject has oral candidiasis. In such cases, following the consumption of foods containing carbohydrates, a fermentation process occurs in the mouth, the first stage of which is glycolysis, proceeding according to the Embden-Meyerhof-Parnas pathway, which is typical in eukaryotes. The main organic substrate in this case is glucose, which is formed in the oral cavity from disaccharides (maltose, sucrose) by the activity of α-amylase. Some mutated fungal strains of the genus Candida acquire the ability to break down sucrose and produce glucoamylase. Glucose is converted into glyceraldehyde 3-phosphate and then into pyruvate. The next stage of fermentation is the decarboxylation of pyruvate into acetaldehyde, a reaction catalyzed by pyruvate decarboxylase. The final stage is the reduction of acetaldehyde to ethanol by alcohol dehydrogenase. Such endogenous production of alcohol can be confused with its consumption, which can cause not only legal, but also social and medical problems. [ABSTRACT FROM AUTHOR]