The Exploitation of Host Iron Sources by Candida albicans during Oral Infection

Tight binding of iron by host proteins provides a natural resistance to microbial infections described as “nutritional immunity”. Inside oral epithelial cells, iron is stored in ferritin. The aim of this study was to determine the natural iron sources for the human pathogenic fungus Candida albicans during oral infection. In vitro, C. albicans can grow at physiological pH with ferritin as the sole source of iron while the baker’s yeast Saccharomyces cerevisiae cannot. Moreover, C. albicans is only able to use ferritin as an iron source under conditions which permit acid production and acidification of the surrounding environment. A screen of mutants lacking components of each of the three iron acquisition systems of C. albicans revealed that only the reductive pathway is involved in ferritin iron utilisation. Additionally, hyphae but not yeast cells of this fungus can bind ferritin and this binding is essential for iron acquisition from ferritin. Transcriptional analysis of C. albicans cells binding ferritin suggested a role for the hyphal-associated protein Als3p in binding of ferritin. Indeed, hyphae of a mutant lacking Als3p were unable to bind ferritin. Furthermore, heterologous expression of Als3p allowed S. cerevisiae to bind ferritin, suggesting that Als3p is a ferritin receptor. Immunofluorescence localisation of ferritin in epithelial cells infected with C. albicans showed ferritin surrounding hyphae from wild type but not Dals3 mutant cells. In summary, this study suggests that C. albicans can use ferritin as an iron source via direct binding by Als3 on the surface of hyphae; iron release is then mediated by acidification and uptake is facilitated by the reductive pathway. This is the first study which demonstrates that a pathogenic microbe can directly use ferritin as an iron source

Métodos alternativos para a detecção de pirogênios em produtos e ambientes sujeitos a Vigilância Sanitária: avanços e perspectivas no Brasil a partir do reconhecimento internacional do Teste de Ativação de Monócitos

Introduction: The detection of pyrogens is essential for the quality control of injectable products. The Rabbit Pyrogen Test remains widely used, despite the existence of alternative methods such as the Monocyte Activation Test (MAT). Objective: To review the use of alternative methods for pyrogen testing, pointing out advances and perspectives from the recognition of MAT by the European pharmacopoeia and its acceptance for regulatory purposes in Brazil. Method: A search was performed on the PubMed and BVS databases, with further classification, categorization by topic and critical analysis of the results. Results: Twenty-four papers were identified, addressing topics such as applications of MAT, its validation and comparisons with in vivo tests. MAT presented better results when compared to other tests, both in the evaluation of biological products and in the detection of non-endotoxin pyrogens. Limitations to diffusion include difficulties in obtaining whole human blood as a source of monocytes, for which several alternatives have been proposed. Conclusions: MAT is a promising method, with application in safety evaluation of new technologies. Its application in Brazil depends on a national implementation policy, which might include greater integration between BraCVAM, Concea and RENAMA in search for its recognition for regulatory purposes.Introdução: A detecção de pirogênios é imprescindível no controle da qualidade de produtos injetáveis. O Teste de Pirogênio em coelhos ainda tem larga aplicação, apesar da existência de métodos alternativos como o Teste de Ativação de Monócitos (MAT). Objetivo: Revisar o uso dos métodos alternativos no teste de pirogênio, apontando avanços e perspectivas a partir do reconhecimento do MAT pela Farmacopeia Europeia e sua aceitação para fins regulatórios no Brasil. Método: Uma busca foi realizada nas bases PubMed e BVS, com posterior classificação, categorização por assuntos e análise crítica dos resultados. Resultados: Foram identificados 24 trabalhos, abordando temas como as aplicações do MAT, sua validação e comparação com testes in vivo. O MAT apresentou melhores resultados quando comparado a outros testes, tanto na avaliação de produtos biológicos como na detecção de pirogênios não-endotoxinas. Limitações para sua difusão incluem a dificuldade de obtenção de sangue total humano como fonte de monócitos, para o qual diversas alternativas têm sido propostas. Conclusões: O MAT se mostra um método promissor, com aplicação na avaliação da segurança de novas tecnologias. Sua aplicação no Brasil depende de uma política nacional de implantação, que inclua maior Integração entre BraCVAM, Concea e RENAMA na busca por seu reconhecimento para fins regulatórios

ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

USO DE COMPUESTOS NATURALES PARA REDUCIR LA CARGA BACTERIANA DE LA CAVIDAD ORAL: UN ARTÍCULO DE REVISIÓN

Currently, there is a wide range of pharmaceutical products that off er great benefi ts for the treatment of various oral diseases. Most of these products are of synthetic origin with antibacterial properties but there are the numerous side eff ects associated with their use. An alternative is the use of natural products from plants and insects in the reduction of the bacterial load of the oral cavity as chamomile (Chamaemelum nobile (L.) All.), cocoa (Th eobroma cacao L.), aloe (Aloe vera L.), moringa (Moringa oleifera Lam.), oregano (Origanum vulgare L.), coconut (Cocos nucifera L.), garlic (Allium sativum L.), clove (Syzgium aromaticum L.), cardamom (Elettaria cardamomum L.), stevia (Stevia rebaudiana Bertoni), honey bee and propolis, addressed in this literature review. Th is review attempts to address the use of diff erent natural compounds in reducing the bacterial load of the oral cavity. It can be concluded that there are several studies about the eff ects of natural products on the part of man in medicine, where there are a large number of works and publications related to natural substances with active ingredients in reducing the bacterial load of the oral cavity.Actualmente, existe una amplia gama de productos farmacéuticos que ofrecen grandes benefi cios para el tratamiento de diversas enfermedades orales. La mayoría de estos productos son de origen sintético con propiedades antibacterianas, pero existen numerosos efectos secundarios asociados con su uso. Una alternativa es el uso de productos naturales de plantas e insectos en la reducción de la carga bacteriana de la cavidad oral como la manzanilla (Chamaemelum nobile (L.) All.), el cacao (Th eobroma cacao L.), el aloe (Aloe vera L.), la moringa (Moringa oleífera Lam.), el orégano (Origanum vulgare L.), coco (Cocos nucifera L.), ajo (Allium sativum L.), clavo (Syzgium aromaticum L.), cardamomo (Elettaria cardamomum L.), stevia (Stevia rebaudiana Bertoni), miel de abeja y propóleos, abordados en esta revisión de la literatura. Esta revisión intenta abordar el uso de diferentes compuestos naturales para reducir la carga bacteriana de la cavidad oral. Se puede concluir que existen varios estudios sobre los efectos de los productos naturales por parte del hombre en la medicina, donde hay una gran cantidad de trabajos y publicaciones relacionadas con sustancias naturales con ingredientes activos para reducir la carga bacteriana de la cavidad oral

Aspergillus fumigatus calcineurin interacts with a nucleoside diphosphate kinase

The Ca2+-calcineurin pathway affects virulence and morphogenesis in filamentous fungi. Here, we identified 37 CalA-interacting proteins that interact with the catalytic subunit of calcineurin (CalA) in Aspergillus fumigatus, including the nucleoside diphosphate kinase (SwoH). The in vivo interaction between CalA and SwoH was validated by bimolecular fluorescence complementation. A. fumigatus swoH is an essential gene. Therefore, a temperature-sensitive conditional mutant strain with a point mutation in the active site, SwoH(V83F), was constructed, which demonstrated reduced growth and increased sensitivity to elevated temperatures. The SwoH(V83F) mutation did not cause a loss in virulence in the Galleria mellonella infection model. Taken together these results imply that CalA interacts with SwoH. (C) 2012 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), BrazilConselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brazi

Evaluation of brushing efficiency in reducing oral microbiota in mechanically ventilated patients admitted to an intensive care unit

Summary: Background: Patients admitted to the Intensive Care Unit (ICU) are at greater risk of developing nosocomial infections due to their investigations, treatment and changes in the immune system. One of the most prevalent nosocomial infections is respiratory tract infection, such as hospital acquired pneumonia and ventilator-associated pneumonia (VAP). The bacteria commonly found in the oral cavity in the hospital environment are Streptococcus viridians, Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus spp., and Klebsiella pneumoniae. There is a need to test and define appropriate standard protocols for oral hygiene in patients undergoing mechanical ventilation in ICUs through the intervention of a dental specialist, preventing the proliferation of microorganisms into the respiratory tract, thus reducing hospitalization time, the use of antibiotics, and increased morbidity/mortality. Objective: This study aimed to evaluate the effectiveness of dental brushing in the reduction of the pathogenic buccal microbiota associated with mechanical ventilation in patients admitted to the Evangelical Hospital from Londrina, Paraná, Brazil. Methodology: The sample consisted of 90 patients (of both sexes), mean age of 65 years, under mechanical ventilation by orotracheal tube and tracheostomized patients, without suspected or confirmed diagnosis of pneumonia. Patients were randomized ∗∗∗ Results: Results showed that oral hygiene using a toothbrush by suction, with chlorhexidine gel 0.12% (Group B), was more effective than conventional hygiene using gauze soaked with chlorhexidine 0.12% (Group A) in reducing pathogenic buccal microbiota. Conclusions: There was a reduction of the pathogenic buccal microbiota in mechanically ventilated patients receiving oral hygiene using a toothbrush by suction with chlorhexidine gel 0.12% (Group B

In Vitro Evaluation of the Remineralizing Potential and Antimicrobial Activity of a Cariostatic Agent with Silver Nanoparticles

<div><p>Abstract Cariostatic treatment has been shown to successfully arrest caries. However, it blackens the carious tooth structure. This study evaluated the effects of an experimental cariostatic agent with silver nanoparticles (Ag-Nano) using microhardness (MH) and microbiological tests. The cariostatic agents tested were: Saforide®, Cariestop®, Ancarie® and Ag-Nano. Sixty-six samples from deciduous enamel were submitted to initial (after pH cycling to obtain initial caries-like lesion) and final (after cariostatic application) MH testing and %MH values were calculated. After longitudinal sectioning, internal (I) MH was evaluated. Strains of Streptococcus mutans, Escherichia coli, and Enterococcus faecalis in brain-heart infusion culture were treated with the cariostatic agents. Agar diffusion tests (ADTs) were performed and minimum inhibitory concentrations were determined. The statistical tests used were: Kruskal-Wallis and Dunn (%MD; ADT; MIC) and ANOVA followed by Tukey’s test (I-MH) (p<0.05). The %MH of Saforide® was significantly greater than that of Ag-Nano (p<0.05). Internal MH showed progressive improvement in the enamel remineralization for all cariostatic tested. In ADTs showed greater inhibition of S. mutans, E. faecalis, and E. coli by Saforide® than by Ancarie® and Ag-Nano. Ag-Nano was able to inhibit 100% microorganism growth at a lower concentration than required for the other agents. It was concluded that Ag-Nano treatment promoted remineralization of deciduous tooth enamel with initial caries-like lesion and bactericidal activity.</p></div

ChIP-seq reveals a role for CrzA in the Aspergillus fumigatus high-osmolarity glycerol response (HOG) signalling pathway

Aspergillus fumigatus is an opportunistic pathogen and allergen of mammals. Calcium signalling is essential for A. fumigatus pathogenicity and is regulated by the CrzA transcription factor. We used ChIP-seq (Chromatin Immunoprecipitation DNA sequencing) to explore CrzA gene targets in A. fumigatus. In total, 165 potential binding peaks including 102 directly regulated genes were identified, resulting in the prediction of the A[GT][CG]CA[AC][AG] CrzA-binding motif. The 102 CrzA putatively regulated genes exhibited a diverse array of functions. The phkB (Afu3g12530) histidine kinase and the sskB (Afu1g10940) MAP kinase kinase kinase of the HOG (high-osmolarity glycerol response) pathway were regulated by CrzA. Several members of the two-component system (TCS) and the HOG pathway were more sensitive to calcium. CrzAConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP