Spórafelszíni fehérjéket kódoló gének jellemzése Mucor circinelloides-ben

Mucormycosis is an invasive fungal infection caused by certain members of the filamentous fungal order Mucorales. It most frequently occurs in patients who have an underlying immunocompromised status due to immunosuppressive treatment or haematological malignancy. The species most frequently identified as the etiological agents of mucormycosis belong to the genera Rhizopus, Lichtheimia and Mucor. The frequency of systemic mucormycosis has been increasing, mainly because of the elevating ratio of susceptible population. Furthermore, Mucorales fungi display intrinsic resistance to the majority of routinely used antifungal agents (e.g., echinocandins and azoles), which also limits the number of possible therapeutic options. All of the above mentioned issues urge the improvement of molecular identification methods and the discovery of new antifungal targets.To achieve these goals, clarification of the pathomechanism of mucormycosis, understanding the interaction of these fungi with their hosts, and the identification of potential virulence factors and new biomarkers are essential. All these studies need the adaptation and routine application of molecular and genetic manipulation methods. Appropriate tools for genetic manipulation, including efficient and reliable methods for genetic transformation, are basic requirements of cell biological and molecular studies, as well as of strain improvement by genetic and metabolic engineering. As recent results have pointed out the importance of the CotH protein family in connection with virulence, our research was focused mainly on the extensive analysis of these genes and the clarification of their role in the virulence. However, that only a subset of the putative spore surface proteins identified in the Mucor genome showed homology to Rhizopus proteins associated with fungal pathogenicity. Thus, we also had to consider the possibility that the CotH family is a diverse group of proteins involved in many biological processes, and so forth we designed several experiments to elucidate the role of spore surface proteins in Mucor. Based on this, we attempted to perform the functional analysis of the CotH proteins, which involved monitoring the phenotypic alterations of genetically stable mutants created using CRISPR-Cas9 system. To reveal whether CotH proteins play a role in the pathogenesis and other biological processes of the Mucor circinelloides fungus

In vitro Interactions of Pseudomonas aeruginosa With Scedosporium Species Frequently Associated With Cystic Fibrosis

Members of the Scedosporium apiospermum species complex are the second most frequently isolated pathogens after Aspergillus fumigatus from cystic fibrosis (CF) patients with fungal pulmonary infections. Even so, the main risk factors for the infection are unrevealed. According to previous studies, bacterial infections might reduce the risk of a fungal infection, but an antibacterial therapy may contribute to the airway colonization by several fungal pathogens. Furthermore, corticosteroids, which are often used to reduce lung inflammation in children and adults with CF, are also proved to enhance the growth of A. fumigatus in vitro. Considering all the above discussed points, we aimed to test how Pseudomonas aeruginosa influences the growth of scedosporia and to investigate the potential effect of commonly applied antibacterial agents and corticosteroids on Scedosporium species. Direct interactions between fungal and bacterial strains were tested using the disk inhibition method. Indirect interactions via volatile compounds were investigated by the plate-in-plate method, while the effect of bacterial media-soluble molecules was tested using a modified cellophane assay and also in liquid culture media conditioned by P. aeruginosa. To test the effect of bacterial signal molecules, antibacterial agents and corticosteroids on the fungal growth, the broth microdilution method was used. We also investigated the germination ability of Scedosporium conidia in the presence of pyocyanin and diffusible signal factor by microscopy. According to our results, P. aeruginosa either inhibited or enhanced the growth of scedosporia depending on the culture conditions and the mode of interactions. When the two pathogens were cultured physically separately from each other in the plate-in-plate tests, the presence of the bacteria was able to stimulate the growth of several fungal isolates. While in direct physical contact, bacterial strains inhibited the fungal growth. This effect might be attributed to bacterial signal molecules, which also proved to inhibit the germination and growth of scedosporia. In addition, antibacterial agents showed growth-promoting, while corticosteroids exhibited growth inhibitory effect on several Scedosporium isolates. These data raise the possibility that a P. aeruginosa infection or a previously administered antibacterial therapy might be able to increase the chance of a Scedosporium colonization in a CF lung

Characterization of the Sterol 24-C-Methyltransferase Genes Reveals a Network of Alternative Sterol Biosynthetic Pathways in Mucor lusitanicus

The fungal membrane contains ergosterol instead of cholesterol, which offers a specific point of attack for the defense against pathogenic fungi. Indeed, most antifungal agents target ergosterol or its biosynthesis

In Vitro Activity of Selected Phenolic Compounds against Planktonic and Biofilm Cells of Food-Contaminating Yeasts

Phenolic compounds are natural substances that can be obtained from plants. Many of them are potent growth inhibitors of foodborne pathogenic microorganisms, however, phenolic activities against spoilage yeasts are rarely studied. In this study, planktonic and biofilm growth, and the adhesion capacity of Pichia anomala, Saccharomyces cerevisiae, Schizosaccharomyces pombe and Debaryomyces hansenii spoilage yeasts were investigated in the presence of hydroxybenzoic acid, hydroxycinnamic acid, stilbene, flavonoid and phenolic aldehyde compounds. The results showed significant anti-yeast properties for many phenolics. Among the tested molecules, cinnamic acid and vanillin exhibited the highest antimicrobial activity with minimum inhibitory concentration (MIC) values from 500 µg/mL to 2 mg/mL. Quercetin, (−)-epicatechin, resveratrol, 4-hydroxybenzaldehyde, p-coumaric acid and ferulic acid were also efficient growth inhibitors for certain yeasts with a MIC of 2 mg/mL. The D. hansenii, P. anomala and S. pombe biofilms were the most sensitive to the phenolics, while the S. cerevisiae biofilm was quite resistant against the activity of the compounds. Fluorescence microscopy revealed disrupted biofilm matrix on glass surfaces in the presence of certain phenolics. Highest antiadhesion activity was registered for cinnamic acid with inhibition effects between 48% and 91%. The active phenolics can be natural interventions against food-contaminating yeasts in future preservative developments