Today is known that genus Malassezia includes seven species: M. furfur, M. sympodialis, M. obtusa, M. globosa, M. restricta, M. sloofflae and M. pachydermatis, but role of each of the species in the pathogenesis of disease has not been elucidated yet, so further laboratory isolation and identification are necessary. We report the first case of isolation of Malassezia globosa in Serbia (Belgrade), in a patient suffering from Pityriasis versicolor. Identification of M. globosa was based on macroscopic, microscopic and biochemical characteristics. Isolation was done on Leeming and Notman medium and on mDixona agar, at 350C, during 7 days in aerobic conditions. Also the yeast's biochemical phenotype was determined as catalase (+), lipase (+), esculin degradation (-), Tween (20, 40, 60 and 80) assimilation (-). M. globosa is a lipophilic yeast of the genus Malassezia and the common member of the skin flora. In concordance with some predisponing factors M. globosa is implicated in the pathogenesis of several skin diseases (pityriasis versicolor, malassezia foliculitis, seborheic dermatitis and some forms of atopic dermatitis). In immunocompromised patients and neonates this yeast can even cause fatal systemic infections. Because the role of Malassezia spp. In pathogenesis of skin disease is not still determined, we suggest laboratory diagnosis and identification of these species as a routine diagnostic procedure.

NK and T cells play a pivotal role in host defense to Cryptococcus neoformans (C. neoformans) fungus which affects especially hosts with impaired cell mediated immunity. The vaccine against cryptococcosus is not developed yet, thus we established an animal BALB/c mice model to analyze anticryprococcal activity of immune cells. We detected that non-stimulated spleen mononuclear cells (MNC) from non-immunized mice have the capacity to exhibit anticriptococcal activity on the incapsulated C. neoformans strain (ATCC 34873) and this activity can be enhanced by non-adherent cells (NAC). In order to obtained antigen-specific anticryprococcal activity, MNC and NAC were stimulated in vitro with corpuscular (Ag1) or soluble (Ag2) C. neoformans antigen prepared from the acapsular strain Cap67 (ATCC 52817). In vitro stimulation of immune cells with both C. neoformans antigens enhanced the anticryptococcal activity of MNC and NAC. NAC fraction expressed the highest anticryptococcal activity, also in the presence and in the absence of accessory cells (AC). The highest anticryptococcal activity of effector cells was detected after immunization of mice with the same C. neoformans antigens and after additional stimulation of immune cells in vitro with the some antigens. These data demonstrated that growth inhibition of C. neoformans mediated by mice effector cells can be enhanced with corpuscular, as well as soluble antigens. Thus designin an animal model which is simple and reproducible and can be used for further studies and development of immunization strategies against human cryptococcosis

The encapsulated fungal pathogen Cryptococcus neoformans is a significant agent of life-threatening infections, particularly in people with suppressed cell-mediated immunity. The cellular cytotoxicity against C. neoformans infection is mainly mediated by NK and T cells, but effector mechanisms are not well understood. The objective of this study was (i) to determine whether prior exposure to the cryptococcal antigens enhances anticryptococcal activity of cytotoxic cells in mice and (ii) the contribution of perforin- and nonperforin-mediated cytotoxicity of NK and T cells in growth inhibition of C. neoformans. Our data showed that in vitro exposure of nonadherent (NA) spleen mononuclear cells from nonimmunized mice to heat-killed C. neoformans strain Cap67 unencapsulated mutant of B3501 (Ag1) or its supernatant (Ag2) demonstrated higher anticryptococcal activity. This effector mechanism can be enhanced further after immunization with either Ag1 or Ag2. There is a synergistic effect of immunization and in vitro incubation of the NA cells with the same antigens. Concanamycin A (CMA) and strontium chloride (SrCl2) inhibition assays were performed to clarify the contribution of perforin- and nonperforin-mediated anticryptococcal cytotoxicity of NA cells in these events. Treatment with these inhibitors demonstrated that anticryptococcal cytotoxicity of nonprimed NA cells was primarily perforin mediated. Anticryptococcal activity of the NA cells obtained from immunized mice after in vitro incubation with cryptococcal antigens was both perforin and nonperforin mediated. Taken together these data demonstrate that in mice a nonperforin-mediated pathway of anticryptococcal cytotoxicity can be induced by immunization. Further research is needed to examine their potential role for human vaccines strategies and/or therapies.

The fatality rate of invasive aspergillosis (IA) is still very high, especially in prolonged and untreated pulmonary cases. Aspergillus fumigatus is the main causative agent of IA and investigation of its metabolites could provide valuable insight into virulence factor(s) associated with this organism. We evaluated the A. fumigatus culture filtrate (CF) products generated during short- and long-term aerated and non-aerated conditions and tested for (i) inhibition of cysteine or serine proteases and (ii) cytotoxicity. In addition, the mathematical model was determined using response surface methodology (RSM) to estimate the influence of different fermentation conditions on A. fumigatus CF characteristics, predict enzyme inhibition and make possible correlations with in vivo conditions. Biosynthesis of A. fumigatus low molecular weight proteinaceous products (from 6.4 to 15.4 kDa) was observed after 6 days of growth under aerated and alkaline conditions. Also, only these CFs showed significant reduction in cell lines survival (Caco-2 and WISH 35.6% and 54.6%, respectively). Obtained results provide solid starting point for further studies that would include: (i) detailed chemical characterization of A. fumigatus CF, (ii) activity relationships and in vivo correlation with pathogenicity of prolonged pulmonary IA and (iii) possible use of biomolecules as diagnostic or therapeutic markers.

Adolescence brings with it different types of changes in people – such as physical, emotional and cognitive, which can be quite stressful. Some of the factors that can be protective against stress in the transition period of high school completion are the locus of control and perceived social support. The aim of the study is to examine whether, and to what extent, stress levels in adolescents can be predicted based on the locus of control of adolescents as well as based on perceived social support. The research examined 190 adult high school students (Nmale = 80; Nfemale = 110) from six municipalities in Serbia. The following instruments were used: Perceived Stress Scale (PSS-10), Multidimensional Scale of Perceived Social Support (MSPSS), and The Multidimensional Locus of Control (IPC). The results showed that the dimensions Internal locus of control (β = - .30, p < .000), Family support (β = -.21, p = .002) and Powerful others (β = .190, p = .020) contribute statistically significantly to explaining the level variance stress in adolescents. Considering the intergroup differences by gender, it can be concluded that boys and girls differ statistically significantly only on the variable Stress, i.e., that girls have a higher level of stress compared to boys, t (188) = -2.411, p =.017. The only statistically significant intergroup difference when it comes to the order of birth is observed in the variable Internal locus of control, t (188) = -2.116, p =.036, where in first-born children a statistically significantly lower level of internal locus of control can be found compared to children born later. Key words: stress, adolescence, locus of control, perceived social support