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Several biodegradation experiments were carried out using 10 different yeast strains.Saccharomyces spp., Kluyveromyces spp. andRhodotorula spp. were tested for biodegradation of selected mycotoxins (ochratoxin A, nivalenol, deoxynivalenol and fumonisin B1) standardsin vitro. There was confirmed that some yeast strains are able to degrade some mycotoxins. However, great differences between individual strains were observed. Moreover, 12Saccharomyces cerevisiae strains were tested for their potential capability to degrade zearalenone and fumonisins in Sabouraud broth. Two strains were capable to degrade zearalenone totally, one strain decreased the mycotoxin concentration up to 25%, and one strain up to 75% of original amount. Two strains were capable to degrade fumonisins partially.

Introduction. The virulence of Candida albicans is conditioned by several virulence factors, one of which is the formation of biofilm which reduces the sensitivity of the yeast to conventional antimycotics. This study determines the antifungal and antibiofilm activity of five essential oils (EOs) of the Lamiaceae family: Salvia officinalis, Thymus vulgaris, Rosmarinus officinalis, Origanum vulgare, and Hyssopus officinalis. Materials and method. In the preliminary research, the antifungal effect of eachof the EOs was tested in the concentration range of 200-0.4 mg/mL on planktonic Candida albicans (C. albicans) cells. A total of 13 C. albicans clinical isolates and one reference strain were evaluated on biofilm formation. Results. Nine isolates (69.2%) showed weak biofilm production and four strains (30.8%) were detected as moderate biofilm producers. The EOs of Thymus vulgaris and Origanum vulgare were seen as effective antifungal agents on planktonic cells with the MIC 0.4 mg/mL. The highest average MIC values were recorded in Salvia officinalis EO (24.0 and 14.8 mg/mL). All isolates were used to determine EOs efficacy on the inhibition of adherence phase and biofilm formation. The biofilm production of C. albicans after exposition by EOs was quantitatively examined by crystal violet dye. Conclusions.The most effective for adherence phase and biofilm formation were EOs of Origanum vulgare (0.1 mg/mL and 0.3 mg/mL) and Thymus vulgaris (0.1 mg/mL and 0.4 mg/mL). The obtained results show that EOs of Thymus vulgaris and Origanum vulgare are potential agents for antifungal treatment or prophylaxis by reducing the resistance of pathogen.

The cereal samples were taken immediately after harvest from the selected localities of Poland (45 samples) and East Slovakia (60 samples). Fungal contamination of these samples was investigated and subsequently the presence of two important mycotoxins, deoxynivalenol (DON) and ochratoxin A (OTA), was quantitatively examined. Concerning mould contamination, no difference was observed between the samples from Poland and East Slovakia. The highest incidence was observed of Fusarium, Aspergillus, and Penicillium genera. However, most of the investigated samples of wheat, rye, and barley contained less than 10 4 cfu/g. The limit 750 ppb for DON in cereals and their products, recommended by the European Mycotoxin Awareness Network (EMAN), was exceeded only by one wheat sample (4.5%) from Poland, but by seven wheat samples (14.6%) from Slovakia. None cereal sample investigated for OTA exceeded the allowed limit -5 µg/kg.

The aim of the study was to determine the effect of repeated applications of aflatoxin B1 (AFB1) on immunocompetent cells (CD3 T cells) and alkaline phosphatase in the intestinal mucosa. Mice were orally treated with AFB1 for 24 days. The mucosa of the intestine showed a significant decrease in the number of CD3 T cells and a significantly lower level activity of alkaline phosphatase on day 24 in AFB1 treated mice. Similarly, with changes in the small intestine, qualitative haematological parameters were modified in systemic immunity as lymphopenia, and neutropenia, monocytopenia. AFB1 treated animals showed reduction in body weight gain and increased liver weight. We supposed that changes found in the small intestine are secondary to primary systemic haematological lesions. The decrease in CD3 T cells suggests a connection with the decrease in the host's resistance to infectious diseases.

The antifungal activities of 14 selected essential oils (at the concentrations of 0.5 %, 5 %, and 30 %) against the yeast Malassezia pachydermatis (18 isolates and one reference strain) were investigated. The isolates of M. pachydermatis were obtained from swabs of external ear canals of healthy dogs using sterile swabs. The determination of the efficacy was based on a modified disc diffusion method (CLSI M44-A2). The best antifungal efficacy (100 %) was shown by clove, cinnamon and oregano at the concentration of 30 %; less significant efficacy was shown at the concentration of 5 % (38 %, 33 % and 5 %, respectively). Satureja inhibited the growth of Malassezia (efficacy of 16 %) only at the concentration of 30 %. Bergamot, lavender, juniper, cedar, sage, tea-tree, grapefruit, pine, chamomile and yarrow essential oils were not able to form inhibition zones as defined in the methodology used (greater or equal to 15 mm) in all concentrations used. Therefore, according to the interpretation criterion, they were considered ineffective. In all cases, the concentration of 0.5 % was not effective against the growth of Malassezia yeasts.

Yeasts from the genus Malassezia belongs to normal commensal skin flora of warm-blooded vertebrates. These yeasts may act as opportunistic pathogens and cause skin diseases in humans and animals under certain conditions. The identification of Malassezia species is based on the phenotypic or genotypic diagnostics. The methods used for the phenotypic identification is determined by: the growth on Sabouraud agar, growth on selective media (Leeming-Notman agar, Dixon agar, Chrom Malassezia agar), the ability to utilise different concentrations of Tween, monitoring of the growth on CEL agar (soil enriched with castor oil) and TE agar (Tween-esculine agar), and the catalase test. The genotypic identification uses molecular methods like: the pulsed field gel electrophoresis (PFGE), random amplified polymorphic DNA (RAPD), amplified fragment lenght polymorphism (AFLP), denaturing gradient gel electrophoresis (DGGE), and the DNA sequence analysis.