Growth inhibition and ultrastructural alterations induced by Δ24(25)-sterol methyltransferase inhibitors in Candida spp. isolates, including non-albicans organisms

<p>Abstract</p> <p>Background</p> <p>Although <it>Candida </it>species are commensal microorganisms, they can cause many invasive fungal infections. In addition, antifungal resistance can contribute to failure of treatment.</p> <p>The purpose of this study was to evaluate the antifungal activity of inhibitors of Δ²⁴⁽²⁵⁾-sterol methyltransferase (24-SMTI), 20-piperidin-2-yl-5α-pregnan-3β-20(R)-diol (AZA), and 24(R,S),25-epiminolanosterol (EIL), against clinical isolates of <it>Candida </it>spp., analysing the ultrastructural changes.</p> <p>Results</p> <p>AZA and EIL were found to be potent growth inhibitors of <it>Candida </it>spp. isolates. The median MIC₅₀was 0.5 μg.ml^-1for AZA and 2 μg.ml^-1for EIL, and the MIC₉₀was 2 μg.ml^-1for both compounds. All strains used in this study were susceptible to amphotericin B; however, some isolates were fluconazole- and itraconazole-resistant. Most of the azole-resistant isolates were <it>Candida </it>non-<it>albicans </it>(CNA) species, but several of them, such as <it>C. guilliermondii, C. zeylanoides</it>, and <it>C. lipolytica</it>, were susceptible to 24-SMTI, indicating a lack of cross-resistance. Reference strain <it>C. krusei </it>(ATCC 6258, FLC-resistant) was consistently susceptible to AZA, although not to EIL. The fungicidal activity of 24-SMTI was particularly high against CNA isolates. Treatment with sub-inhibitory concentrations of AZA and EIL induced several ultrastructural alterations, including changes in the cell-wall shape and thickness, a pronounced disconnection between the cell wall and cytoplasm with an electron-lucent zone between them, mitochondrial swelling, and the presence of electron-dense vacuoles. Fluorescence microscopy analyses indicated an accumulation of lipid bodies and alterations in the cell cycle of the yeasts. The selectivity of 24-SMTI for fungal cells versus mammalian cells was assessed by the sulforhodamine B viability assay.</p> <p>Conclusion</p> <p>Taken together, these results suggest that inhibition of 24-SMT may be a novel approach to control <it>Candida </it>spp. infections, including those caused by azole-resistant strains.</p

Nosocomial candidiasis in Rio de Janeiro State: Distribution and fluconazole susceptibility profile

One hundred and forty-one Candida species isolated from clinical specimens of hospitalized patients in Rio de Janeiro, Brazil, during 2002 to 2007, were analized in order to evaluate the distribution and susceptibility of these species to fluconazole. Candida albicans was the most frequent species (45.4%), followed by C. parapsilosis sensu lato (28.4%), C. tropicalis (14.2%), C. guilliermondii (6.4%), C. famata (2.8%), C. glabrata (1.4%), C. krusei (0.7%) and C. lambica (0.7%). The sources of fungal isolates were blood (47.5%), respiratory tract (17.7%), urinary tract (16.3%), skin and mucous membrane (7.1%), catheter (5.6%), feces (2.1%) and mitral valve tissue (0.7%). The susceptibility test was performed using the methodology of disk-diffusion in agar as recommended in the M44-A2 Document of the Clinical and Laboratory Standards Institute (CLSI). The majority of the clinical isolates (97.2%) was susceptible (S) to fluconazole, although three isolates (2.1%) were susceptible-dose dependent (S-DD) and one of them (0.7%) was resistant (R). The S-DD isolates were C. albicans, C. parapsilosis sensu lato and C. tropicalis. One isolate of C. krusei was resistant to fluconazole. This work documents the high susceptibility to fluconazole by Candida species isolated in Rio de Janeiro, Brazil

Cellular characterisation of Candida tropicalis presenting fluconazole-related trailing growth

We assessed fluconazole susceptibility in 52 Candida tropicalis clinical strains using seven antifungal susceptibility methods, including broth microdilution (BMD) [standard M27 A3 (with neutral and acid pH), ATB Fungus 3, Vitek 2 system and flow cytometric analysis] and agar-based methods (disk diffusion and E-test). Trailing growth, detection of cell-associated secreted aspartic proteases (Saps) and morphological and ultrastructural traits of these clinical strains were also examined. The ranges of fluconazole 24 h-minimum inhibitory concentration (MIC) values were similar among all methods. The essential agreement among the methods used for MIC determinations was excellent and all methods categorised all strains as susceptible, except for one strain that showed a minor error. The presence of the trailing effect was assessed by six methods. Trailing positivity was observed for 86.5-100% of the strains. The exception was the BMD-Ac method where trailing growth was not observed. Morphological and ultrastructural alterations were detected in C. tropicalis trailing cells, including mitochondrial swelling and cell walls with irregular shapes. We tested the production of Saps in 13 C. tropicalis strains expressing trailing growth through flow cytometry. Our results showed that all of the C. tropicalis strains up-regulated surface Sap expression after 24 h or 48 h of exposure to fluconazole, which was not observed in untreated yeast strains. We concluded that C. tropicalis strains expressing trailing growth presented some particular features on both biological and ultrastructural levels

Duration of post-vaccination immunity against yellow fever in adults

Submitted by Nuzia Santos ([email protected]) on 2015-06-22T17:37:43Z No. of bitstreams: 1 2014_152.pdf: 756403 bytes, checksum: c18d98237e29e19e785cf895a2a68ddc (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2015-06-22T17:37:52Z (GMT) No. of bitstreams: 1 2014_152.pdf: 756403 bytes, checksum: c18d98237e29e19e785cf895a2a68ddc (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2015-06-22T17:58:36Z (GMT) No. of bitstreams: 1 2014_152.pdf: 756403 bytes, checksum: c18d98237e29e19e785cf895a2a68ddc (MD5)Made available in DSpace on 2015-06-22T17:58:36Z (GMT). No. of bitstreams: 1 2014_152.pdf: 756403 bytes, checksum: c18d98237e29e19e785cf895a2a68ddc (MD5) Previous issue date: 2014Fundação Oswaldo Cruz. Brasilia, DF, BrasilFundação Oswaldo Cruz. Escola Nacional de Saúde Pública. Rio de Janeiro, RJ, BrazilFundação Oswaldo Cruz. Centro de Pesquisa Rene Rachou. Laboratório de Biomarcadores Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicosde Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos de Bio-Manguinhos. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Centro de Pesquisa Rene Rachou. Laboratório de Biomarcadores. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisa Rene Rachou. Laboratório de Biomarcadores. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisa Rene Rachou. Laboratório de Imunopatologia .Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisa Rene Rachou. Laboratório de Esquistossomose. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisa Rene Rachou. Laboratório de Biomarcadores. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisa Rene Rachou. Laboratório de Biomarcadores. Belo Horizonte, MG, BrasilFood and Drug Administration Center for Biologics Evaluation and Research. Bethesda, USA.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratorio de Fla-vivirus. Rio de JaneiroFundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratorio de Fla-vivirus. Rio de JaneiroFundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratorio de Fla-vivirus. Rio de JaneiroInstituto de Biologia do Exército. Rio de Janeiro, RJ, BrasilInstituto de Biologia do Exército. Rio de Janeiro, RJ, BrasilInstituto de Biologia do Exército. Rio de Janeiro, RJ, BrasilInstituto de Biologia do Exército. Rio de Janeiro, RJ, BrasilInstituto de Biologia do Exército. Rio de Janeiro, RJ, BrasilInstituto de Biologia do Exército. Rio de Janeiro, RJ, BrasilMinas Gerais. Secretaria Estadual de Saude. Belo Horizonte, MG, BrasilMinas Gerais. Secretaria Estadual de Saude. Belo Horizonte, MG, BrasilMinas Gerais. Secretaria Estadual de Saude. Belo Horizonte, MG, BrasilMinas Gerais. Secretaria Estadual de Saude. Belo Horizonte, MG, BrasilUniversidade Federal de Alfenas. Alfenas, MG, BrasilUniversidade de Brasília. Faculdade de Medicina. Brasilia, DF, BrasilFundação Oswaldo Cruz. Instituto Evandro Chagas. Ananindeua, PA, BrasilINTRODUCTION: Available scientific evidence to recommend or to advise against booster doses of yellow fever vaccine (YFV) is inconclusive. A study to estimate the seropositivity rate and geometric mean titres (GMT) of adults with varied times of vaccination was aimed to provide elements to revise the need and the timing of revaccination. METHODS: Adults from the cities of Rio de Janeiro and Alfenas located in non-endemic areas in the Southeast of Brazil, who had one dose of YFV, were tested for YF neutralising antibodies and dengue IgG. Time (in years) since vaccination was based on immunisation cards and other reliable records. RESULTS: From 2011 to 2012 we recruited 691 subjects (73% males), aged 18-83 years. Time since vaccination ranged from 30 days to 18 years. Seropositivity rates (95%C.I.) and GMT (International Units/mL; 95%C.I.) decreased with time since vaccination: 93% (88-96%), 8.8 (7.0-10.9) IU/mL for newly vaccinated; 94% (88-97), 3.0 (2.5-3.6) IU/mL after 1-4 years; 83% (74-90), 2.2 (1.7-2.8) IU/mL after 5-9 years; 76% (68-83), 1.7 (1.4-2.0) IU/mL after 10-11 years; and 85% (80-90), 2.1 (1.7-2.5) IU/mL after 12 years or more. YF seropositivity rates were not affected by previous dengue infection. CONCLUSIONS:Eventhough serological correlates of protection for yellow fever are unknown, seronegativity in vaccinated subjects may indicate primary immunisation failure, or waning of immunity to levels below the protection threshold. Immunogenicity of YFV under routine conditions of immunisation services is likely to be lower than in controlled studies. Moreover, infants and toddlers, who comprise the main target group in YF endemic regions, and populations with high HIV infection rates, respond to YFV with lower antibody levels. In those settings one booster dose, preferably sooner than currently recommended, seems to be necessary to ensure longer protection for all vaccinee

Booster dose after 10 years is recommended following 17DD-YF primary vaccination

Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiologicos Bio-Manguinhos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiologicos Bio-Manguinhos. Rio de Janeiro, RJ, Brasil.Governo do Estado de Minas Gerais. Secretaria de Estado de Saúde. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiologicos Bio-Manguinhos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiologicos Bio-Manguinhos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiologicos Bio-Manguinhos. Rio de Janeiro, RJ, Brasil.Universidade Federal de Alfenas. Alfenas, MG, Brasil.Instituto de Biologia do Exercito. Rio de Janeiro, RJ, Brasil.Instituto de Biologia do Exercito. Rio de Janeiro, RJ, Brasil.Instituto de Biologia do Exercito. Rio de Janeiro, RJ, Brasil.Instituto de Biologia do Exercito. Rio de Janeiro, RJ, Brasil.Instituto de Biologia do Exercito. Rio de Janeiro, RJ, Brasil.Instituto de Biologia do Exercito. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Assessoria Clínica de Bio-Manguinhos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiologicos Bio-Manguinhos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiologicos Bio-Manguinhos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Assessoria Clínica de Bio-Manguinhos. Rio de Janeiro, RJ, Brasil.Ministerio da Saude. Secretaria de Vigilancia em Saude. Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Brasil.Universidade de Brasília. Brasilia, DF, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.US Food and Drug Administration. Center for Biologics Evaluation and Research. Silver Spring, MD USAFundação Oswaldo Cruz. Diretoria Regional de Brasília. Brasília, DF, Brasil.Fundação Oswaldo Cruz. Escola Nacional de Saúde Publica. Rio de Janeiro, DF, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Renê Rachou. Belo Horizonte, MG, Brasil.A single vaccination of Yellow Fever vaccines is believed to confer life-long protection. In this study, results of vaccinees who received a single dose of 17DD-YF immunization followed over 10 y challenge this premise. YF-neutralizing antibodies, subsets of memory T and B cells as well as cytokine-producing lymphocytes were evaluated in groups of adults before (NVday0) and after (PVday30-45, PVyear1-4, PVyear5-9, PVyear10-11, PVyear12-13) 17DD-YF primary vaccination. YF-neutralizing antibodies decrease significantly from PVyear1-4 to PVyear12-13 as compared to PVday30-45, and the seropositivity rates (PRNT≥2.9Log10mIU/mL) become critical (lower than 90%) beyond PVyear5-9. YF-specific memory phenotypes (effector T-cells and classical B-cells) significantly increase at PVday30-45 as compared to na've baseline. Moreover, these phenotypes tend to decrease at PVyear10-11 as compared to PVday30-45. Decreasing levels of TNF-α(+) and IFN-γ(+) produced by CD4(+) and CD8(+) T-cells along with increasing levels of IL-10(+)CD4(+)T-cells were characteristic of anti-YF response over time. Systems biology profiling represented by hierarchic networks revealed that while the na've baseline is characterized by independent micro-nets, primary vaccinees displayed an imbricate network with essential role of central and effector CD8(+) memory T-cell responses. Any putative limitations of this cross-sectional study will certainly be answered by the ongoing longitudinal population-based investigation. Overall, our data support the current Brazilian national immunization policy guidelines that recommend one booster dose 10 y after primary 17DD-YF vaccination