Compêndio de métodos e de boas práticas em coleção de cultura de leveduras do Instituto de Biologia do Exército / Compendium of methods and good practices in yeast culture collection of the Brazilian Army Biology Institute

Objetivo: O Compêndio de Métodos e de Boas Práticas em Coleção de Cultura de Leveduras do Instituto de Biologia do Exército (IBEx) foi elaborado com o propósito de operacionalizar as atividades de pesquisa, garantindo o desempenho seguro e confiável dos seus objetivos regimentais. Métodos: A Coleção de Cultura de Leveduras do IBEx foi criada a partir de cepas isoladas de quadros de candidíase sistêmica, através da utilização de metodologias manuais e automatizadas para autenticação das mesmas, com o propósito de garantir a pesquisa científica e atividades de ensino. Resultados: O Instituto adequou e modernizou seus laboratórios de pesquisa criando o Centro de Estudos em Biodefesa, com Nível de Biossegurança NB-3. Com base na necessidade de organização para atender às demandas da defesa biológica, o IBEx vem aprimorando sua estrutura para dominar e garantir novas tecnologias de identificação e manejo dos microrganismos envolvidos em Bioterrorismo. Conclusão: A compilação de metodologias na forma de um Compêndio proporcionou a operacionalização da Coleção de Cultura do IBEx.

Objective: The Compendium of Methods and Good Practices in Yeast Culture Collection of the Brazilian Army Biology Institute (IBEx) was elaborated with the purpose of operationalizing the research activities, guaranteeing the safe and reliable performance of its regimental objectives. Methods: The IBEx Yeast Culture Collection was created from isolated strains of systemic candidiasis, through the use of manual and automated methodologies to authenticate them, in order to guarantee scientific research and teaching activities. Results: The Institute adapted and modernized its research laboratories by creating the Center for Biodefense Studies, with Biosafety Level NB-3. Based on the need for organization to meet the demands of biological defense, the IBEx has been improving its structure to dominate and guarantee new technologies of identification and management of the microorganisms involved in Bioterrorism. Conclusion: The compilation of methodologies in the form of a Compendium provided the operationalization of the IBEx Culture Collection

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.

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.

Growth inhibition and ultrastructural alterations induced by Delta24(25)-sterol methyltransferase inhibitors in Candida spp. isolates, including non-albicans organisms.

BACKGROUND: Although Candida species are commensal microorganisms, they can cause many invasive fungal infections. In addition, antifungal resistance can contribute to failure of treatment.The purpose of this study was to evaluate the antifungal activity of inhibitors of Delta24(25)-sterol methyltransferase (24-SMTI), 20-piperidin-2-yl-5alpha-pregnan-3beta-20(R)-diol (AZA), and 24(R,S),25-epiminolanosterol (EIL), against clinical isolates of Candida spp., analysing the ultrastructural changes. RESULTS: AZA and EIL were found to be potent growth inhibitors of Candida spp. isolates. The median MIC50 was 0.5 microg.ml-1 for AZA and 2 microg.ml-1 for EIL, and the MIC90 was 2 microg.ml-1 for 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 Candida non-albicans (CNA) species, but several of them, such as C. guilliermondii, C. zeylanoides, and C. lipolytica, were susceptible to 24-SMTI, indicating a lack of cross-resistance. Reference strain C. krusei (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. CONCLUSION: Taken together, these results suggest that inhibition of 24-SMT may be a novel approach to control Candida spp. infections, including those caused by azole-resistant strains.

Prevalência e susceptibilidade in vitro a Itraconazol e Anfotericina B de isolados clínicos de Candida / Prevalence and in vitro susceptibility to Itraconazole and Amphotericin B of clinical Candida isolates

Foram avaliadas 58 cepas de Cândida spp. Recuperada de sangue e cateter de pacientes hospitalizados admitidos em dois hospitais terciários na cidade do Rio de Janeiro, Brasil, num período de três anos. Os isolados foram identificados empregando-se técnicas micológicas de rotina e apresentaram a seguinte distribuição: Cândida parasilosis (47,1%), C. albicans (38,0%), C. tropicalis (6,9%), C. guilliermondii (6,9%), C. iamata (3,4%) e C. globrata (1,7%). Um método de disco-difusão em Agar para estudo de susceptibilidade e antifúngicos foi analisado. Discos de papel com itraconaazol (10g) e anfotericina B (100g) foram depositados sobre o Agar Mueller-Hinton com 2% de glicose e 0,5g/mL de azul de metilene para os ensaios de susceptibilidade. AS cepas foram classificadas como susceptíveis, intermediárias e resistentes pela mensuração dos diâmetros dos halos de inibição. O percentual de susceptibilidade encontrado foi o seguinte: itraconazol, susceptíveis: 91,4% e intermediárias: 8,6%; anfotericina B, susceptíveis: 100%. Cepas resistentes não foram detectadas por este método.