Mycocinogeny in smut yeast-like fungi of the genus Pseudozyma

The fungistatic agent secreted by Pseudozyma prolifica VKM Y-2835 shows activity against some representatives of the Ustilaginales under acidic conditions. This mycocin, with a molecular mass of no less than 15 kDa, is thermolabile and sensitive to proteolytic cleavage.     

Effect of the cultivation conditions of Candida species yeast-like fungi on their sensitivity to levorin]

The effect of levorin on yeast-like fungi under (different) cultivation conditions was studied. It was shown that the medium composition and incubation temperature affected the results of determination of the test-culture sensitivity to levorin. There was correlation between the time of the population lag-phase and the critical time of the zone formation and these values depended on the temperature of the test-microbe vegetation. Strain 037 of C. utilis was more sensitive to levorin and had a longer lag-phase as compared to the other species of the yeast-like fungi, which provided favourable conditions for formation of the growth inhibition zones.     

The characteristics of the ultrastructural changes in yeast-like fungi of the genus Candida exposed to therapeutic-range ultrasound and nystatin]

The electron microscopic study of the ultrastructure of yeast-like fungi of the genus Candida under the action of nystatin and sonication, as well as the action of these two factors used in combination, was carried out. In this study the degree of preservation of the structure of fungal cells was evaluated and the percentage of cells with different ultrastructural changes was determined. Observations made 3 and 24 hours after sonication and treatment with nystatin, used in combination, showed that ultrastructural changes in fungal cells were more pronounced than in the cells subjected to the action of nystatin alone. 24 hours after the combined physico-medicinal treatment of Candida the percentage of nonviable blastospores among them was 5-fold higher than that of such cells among Candida subjected to treatment with nystatin alone and more than 20-fold higher than among Candida subjected only to sonication. These data on the increased fungicidal effect of nystatin used in combination with sonication substantiate the expediency of the above-mentioned physico-medicinal treatment in cases of candidal lesions of the skin and its appendages, which is one of the ways for increasing the effectiveness of the treatment of this mycosis.     

Adhesiveness of yeast-like fungi in the system "Candida albicans--vaginal epitheliocytes"

The influence of vaginal liquid on adhesive reactions in the system "Candida albicans - vaginal epitheliocytes". Preliminary treatment of C. albicans by mucin, natural or absorbed vaginal liquid resulted in decrease of adhesive activity (p<0.05). C. albicans did not change its adhesive properties in case of preliminary treatment of vaginal epitheliocytes by the same substances. In the system "Candida albicans - vaginal epitheliocytes" vaginal liquid has the expressed antiadhesive effect, which probably belongs to mucin.     

Immunochemical study of surface glycoconjugates of yeast-like fungus of the Candida genus

Two complex preparations (extract I and extract II) of surface antigens were obtained from the yeast-like fungus Candida maltosa by treatment of intact cells with beta-mercaptoethylamine and pronase. Immune diffusion in agar gel revealed antigenic heterogeneity of the preparations. Both of the extracts were found to have at least 3 antigenic components. The extracts induce hypersensitivity of intact guinea pigs and candida sensitization on the 12th day after the injection of Candida maltose intact cells into the animals. The common antigen components of extracts I and II were found by means of immunochemical and chromatographic assays. The extracts preserved the antigenic activity after enzyme hydrolysis with pronase.     

Lysozyme activity of fungi of the genus Candida

The capacity of fungi belonging to the genus Candida to produce lysozyme was studied. All 60 strains under study were found to possess pronounced muramidase activity. Among these cultures highly active lysozyme producers were discovered, which would make it possible to use them for production purposes in future.     

Sensitivity of fungi of the genus Candida to antifungal drugs

Seventy two Candida strains isolated from patients with candidiosis of the oral mucosa were studied with respect to their sensitivity to nystatin, levorin, decamine, ethonium, sanguiritrin and clotrimazole. At concentrations of 0.5 to 5 micrograms/ml all the Candida species i.e. C. albicans, C. tropicalis, C. krusei and C. quilliermondii were highly sensitive to clotrimazole. Fungistatic action of levorin, nystatin and sanguiritrin was observed in 91, 67 and 38 per cent of the strains respectively. The Candida strains were resistant to decamine and ethonium used in the above concentrations.     

Use of the coagglutination reaction of yeast-like Candida maltosa fungi for detecting fimbriae in intestinal bacteria

The capacity of nonpathogenic yeast-like C. maltosa strains to coagglutinate Escherichia coli has been studied. C. maltosa cells have also been shown to coagglutinate E. coli possessing mannose-sensitive adhesins in a wide range of their concentrations (5-140 bacterial cells per C. maltosa cell). Strains belonging to types CFA/I and CFA/II with fimbriae, similarly to their corresponding paired genetically related strains without these adhesins, are practically incapable of agglutinating C. maltosa cells, while strains K88 and B41 react with them. The reaction occurs at a concentration of 9.5-37.0 and 38.0-55.5 bacteria respectively per C. maltosa cell and is not inhibited by 1% d-mannose. The suggestion that C. maltosa cell surface glycoproteins contain not only receptors for E. coli fimbriae, type I, but also components similar in their structure to receptors specific to the mannose-resistant adhesins of strains K88, K99 and 41, has been confirmed by hemagglutination inhibition with C. maltosa surface antigens as inhibiting agents.     

Search for biological remedies for fungi of the Candida genus

51 bacterial strains were studied with a view to find out anticandidial activity; of these, 15 strains were found to have activity, more on less expressed with respect to fungi of the genus Candida. In most cases the anticandidial activity of an antagonist strain was manifested to a similar degree against several Candida strains. The preliminary analysis of antifungal substances produced by microbial strains makes it possible to suggest their antibiotic nature.