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1.
Proc Natl Acad Sci U S A ; 119(34): e2202144119, 2022 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-35969785

RESUMO

The metabolic capacity of many cells is tightly regulated and can adapt to changes in metabolic resources according to environmental changes. Tissue-resident memory (TRM) CD8+ T cells are one of the most abundant T cell populations and offer rapid protection against invading pathogens, especially at the epithelia. TRM cells metabolically adapt to their tissue niche, such as the intestinal epithelial barrier. In the small intestine, the types of TRM cells are intraepithelial lymphocytes (IELs), which contain high levels of cytotoxic molecules and express activation markers, suggesting a heightened state of activation. We hypothesize that the tissue environment may determine IEL activity. We show that IEL activation, in line with its semiactive status, is metabolically faster than circulating CD8+ T cells. IEL glycolysis and oxidative phosphorylation (OXPHOS) are interdependently regulated and are dependent on rapid access to metabolites from the environment. IELs are restrained by local availability of metabolites, but, especially, glucose levels determine their activity. Importantly, this enables functional control of intestinal TRM cells by metabolic means within the fragile environment of the intestinal epithelial barrier.


Assuntos
Linfócitos T CD8-Positivos , Linfócitos Intraepiteliais , Células T de Memória , Linfócitos T CD8-Positivos/citologia , Mucosa Intestinal/citologia , Intestinos/citologia , Linfócitos Intraepiteliais/citologia , Ativação Linfocitária , Células T de Memória/citologia , Fosforilação Oxidativa
2.
J Eukaryot Microbiol ; 71(1): e13005, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37877451

RESUMO

Spiny brown dinoflagellate cysts are commonly used as sea-ice indicators in the Arctic, but their biological affinities are not well known. We present the first indication of hitherto temperate Protoperidinium tricingulatum in the Arctic based on single-cell LSU rDNA sequencing from sediments of the Disko Bay-Vaigat Sound, West Greenland. The morphological similarity of the sequenced cyst morphotype to the sea-ice indicator Islandinium? cezare morphotype 1 is striking. The morphology of the isolated cysts, as well as those observed in the total cyst assemblage following standard palynological preparation, both resemble either I.? cezare morphotype 1 or P. tricingulatum, suggesting that the specimens may in fact be close morphological variants of the same species. In addition, nine LSU rDNA sequences were obtained from morphological variants assigned to Islandinium minutum s.l.: including both subspecies minutum and subspecies barbatum. The two subspecies could not be differentiated based on partial LSU rDNA sequencing. Overall, Arctic spiny brown dinoflagellate cyst species may be morphologically more diverse and taxonomically more complex than shown earlier and further genetic and morphological studies are needed. Importantly, the value of cysts as palaeoecological indicators depends on a sound understanding of their biological affinity and taxonomy.


Assuntos
Dinoflagellida , Groenlândia , DNA Ribossômico/genética , Sedimentos Geológicos , Regiões Árticas
3.
Glob Chang Biol ; 29(23): 6503-6516, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37772765

RESUMO

The Pikialasorsuaq (North Water polynya) is an area of local and global cultural and ecological significance. However, over the last decades, the region has been subject to rapid warming, and in some recent years, the seasonal ice arch that has historically defined the polynya's northern boundary has failed to form. Both factors are deemed to alter the polynya's ecosystem functioning. To understand how climate-induced changes to the Pikialasorsuaq impact the basis of the marine food web, we explored diatom community-level responses to changing conditions, from a sediment core spanning the last 3800 years. Four metrics were used: total diatom concentrations, taxonomic composition, mean size, and diversity. Generalized additive model statistics highlight significant changes at ca. 2400, 2050, 1550, 1200, and 130 cal years BP, all coeval with known transitions between colder and warmer intervals of the Late Holocene, and regime shifts in the Pikialasorsuaq. Notably, a weaker/contracted polynya during the Roman Warm Period and Medieval Climate Anomaly caused the diatom community to reorganize via shifts in species composition, with the presence of larger taxa but lower diversity, and significantly reduced export production. This study underlines the high sensitivity of primary producers to changes in the polynya dynamics and illustrates that the strong pulse of early spring cryopelagic diatoms that makes the Pikialasorsuaq exceptionally productive may be jeopardized by rapid warming and associated Nares Strait ice arch destabilization. Future alterations to the phenology of primary producers may disproportionately impact higher trophic levels and keystone species in this region, with implications for Indigenous Peoples and global diversity.


Assuntos
Diatomáceas , Diatomáceas/fisiologia , Ecossistema , Gelo , Clima , Cadeia Alimentar
4.
Environ Microbiol ; 24(10): 4702-4713, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35726894

RESUMO

The expansion of mcr-carrying bacteria is a well-recognized public health problem. Measures to contain mcr spread have mainly been focused on the food-animal production sector. Nevertheless, the spread of MCR producers at the environmental interface particularly driven by the increasing population of gulls in coastal cities has been less explored. Occurrence of mcr-carrying Escherichia coli in gull's colonies faeces on a Portuguese beach was screened over 7 months. Cultural, molecular and genomic approaches were used to characterize their diversity, mcr plasmids and adaptive features. Multidrug-resistant mcr-1-carrying E. coli were detected for 3 consecutive months. Over time, multiple strains were recovered, including zoonotic-related pathogenic E. coli clones (e.g. B2-ST131-H22, A-ST10 and B1-ST162). Diverse mcr-1 genetic environments were mainly associated with ST2/ST4-HI2 (ST10, ST131, ST162, ST354 and ST4204) but also IncI2 (ST12990) plasmids or in the chromosome (ST656). Whole-genome sequencing revealed enrichment of these strains on antibiotic resistance, virulence and metal tolerance genes. Our results underscore gulls as important spreaders of high-priority bacteria and genes that may affect the environment, food-animals and/or humans, potentially undermining One-Health strategies to reduce colistin resistance.


Assuntos
Charadriiformes , Infecções por Escherichia coli , Proteínas de Escherichia coli , Animais , Antibacterianos/farmacologia , Células Clonais , Colistina , Farmacorresistência Bacteriana/genética , Escherichia coli , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Humanos , Proteína 1 Semelhante a Receptor de Interleucina-1/genética , Gado , Testes de Sensibilidade Microbiana , Plasmídeos/genética
5.
Euro Surveill ; 27(22)2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35656830

RESUMO

Up to 27 May 2022, Portugal has detected 96 confirmed cases of monkeypox. We describe 27 confirmed cases (median age: 33 years (range: 22-51); all males), with an earliest symptom onset date of 29 April. Almost all cases (n = 25) live in the Lisbon and Tagus Valley health region. Most cases were neither part of identified transmission chains, nor linked to travel or had contact with symptomatic persons or with animals, suggesting the possible previously undetected spread of monkeypox.


Assuntos
Monkeypox virus , Mpox , Surtos de Doenças , Humanos , Masculino , Mpox/diagnóstico , Mpox/epidemiologia , Monkeypox virus/genética , Portugal/epidemiologia , Viagem
6.
Environ Microbiol ; 23(12): 7563-7577, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34327794

RESUMO

Expansion of mcr-carrying Enterobacteriaceae (MCR-E) is a well-recognized problem affecting animals, humans and the environment. Ongoing global control actions involve colistin restrictions among food-animal production, but their impact on poultry-derived products is largely unknown, justifying comprehensive farm-to-fork studies. Occurrence of MCR-E among 53 chicken-meat batches supplied from 29 Portuguese farms shortly after colistin withdrawal was evaluated. Strains (FT-IR/MLST/WGS), mcr plasmids and their adaptive features were characterized by cultural, molecular and genomic approaches. We found high rates of chicken-meat batches (80%-100% - 4 months; 12% - the last month) with multiple MDR + mcr-1-carrying Escherichia coli (Ec-including ST117 and ST648-Cplx) and Klebsiella pneumoniae (Kp-ST147-O5:K35) clones, some of them persisting over time. The mcr-1 was located in the chromosome (Ec-ST297/16-farms) or dispersed IncX4 (Ec-ST602/ST6469/5-farms), IncHI2-ST2/ST4 (Ec-ST533/ST6469/5 farms and Kp-ST147/6-farms) or IncI2 (Ec-ST117/1-farm) plasmids. WGS revealed high load and diversity in virulence, antibiotic resistance and metal tolerance genes. This study supports colistin withdrawal potential efficacy in poultry production and highlights both poultry-production chain as a source of mcr-1 and the risk of foodborne transmission to poultry-meat consumers. Finally, in the antibiotic reduction/replacement context, other potential co-selective pressures (e.g., metals-Cu as feed additives) need to be further understood to guide concerted, effective and durable actions under 'One Health' perspective.


Assuntos
Colistina , Proteínas de Escherichia coli , Animais , Antibacterianos/farmacologia , Galinhas , Colistina/farmacologia , Farmacorresistência Bacteriana/genética , Enterobacteriaceae/genética , Proteínas de Escherichia coli/genética , Fazendas , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Plasmídeos/genética , Portugal , Aves Domésticas , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Planta Med ; 87(10-11): 754-763, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33882591

RESUMO

To fight the rising resistance of microorganisms to antibiotics, a strategy followed by several researchers is to focus on natural compounds, such as essential oils, as a source of potent antibacterial compounds. These last decades, hundreds of original papers have been written about microbiological assays that prove the antibacterial activity of essential oils and their use in the medical field. But can we really compare all the data available in the literature when the raw material, the microbiological assays, and/or the strains are different from one article to another? This review will point out the differences and the inadequate practices found in published articles that tested 2 lesser-studied essential oils-Spanish lavender and the ajowan-by the broth dilution method against Staphylococcus aureus, a human pathogenic bacterium. Many pitfalls were found in the literature, for example, a variable chemical composition rarely underlined by the authors, unidentified strains or clinical strains used without a related antibiogram, a lack of quality controls, and the assertion of questionable positive results. At last, some general guidelines that should be followed by every scientific researcher will be discussed.


Assuntos
Anti-Infecciosos , Carum , Lavandula , Óleos Voláteis , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Óleos Voláteis/farmacologia
8.
Planta Med ; 87(10-11): 841-849, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34020491

RESUMO

Cocoa bean shell is one of the main by-products of chocolate manufacturing and possesses several compounds with biofunctionalities. It can function as an antibacterial agent, and its action is mostly reported against Streptococcus mutans. However, only a few studies have investigated the cocoa bean shell compounds responsible for this activity. This study aimed to evaluate several extracts of cocoa bean shells from different geographical origins and cocoa varieties and estimate their antimicrobial properties against different fungal and bacterial strains by determining their minimal inhibitory concentration. The results demonstrated antimicrobial activity of cocoa bean shell against one of the tested strains, S. mutans. Cocoa bean shell extracts were further analysed via LC-HRMS for untargeted metabolomic analysis. LC-HRMS data were analysed (preprocessing and statistical analyses) using the Workflow4Metabolomics platform. The latter enabled us to identify possible compounds responsible for the detected antimicrobial activity by comparing the more and less active extracts. Active extracts were not the most abundant in polyphenols but contained higher concentrations of two metabolites. After tentative annotation of these metabolites, one of them was identified and confirmed to be 7-methylxanthine. When tested alone, 7-methylxanthine did not display antibacterial activity. However, a possible cocktail effect due to the synergistic activity of this molecule along with other compounds in the cocoa bean shell extracts cannot be neglected. In conclusion, cocoa bean shell could be a functional ingredient with benefits for human health as it exhibited antibacterial activity against S. mutans. However, the antimicrobial mechanisms still need to be confirmed.


Assuntos
Cacau , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Polifenóis , Streptococcus mutans
9.
Environ Microbiol ; 22(7): 2829-2842, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32281716

RESUMO

Emergence and expansion of frequent multidrug-resistant (MDR) major Salmonella clones/serotypes has been a significant threat in the last years. Metal compounds, such as copper, commonly used in animal-production settings, have been pointed out as possible contributors for the selection of such strains/clones. However, the scarcity of studies limits our understanding of the impact of other metal environmental contaminants as arsenic (used in insecticides/herbicides/coccidiostats). We analysed arsenic tolerance (AsT) dispersion by phenotypic and genotypic (PCR/sequencing/I-CeuI/S1/XbaI-PFGE/hybridization) assays among Salmonella with diverse epidemiological and genetic backgrounds. Then, to better understand ars operon genetic contexts, the whole genome of five representative strains was sequenced. We found a high dispersion of ars operons conferring AsT, especially among copper-tolerant and relevant serotypes/clones related to pig-production setting. The acr3-type was found dispersed in the chromosome of diverse serotypes, including the emergent S. Rissen. Conversely, arsBII was almost confined to the MDR ST34 European clone of S. Typhimurium/S. 4,[5],12:i:-, always along with copper/silver tolerance sil + pco clusters in an integrative conjugative element. These data suggest that AsT is an essential adaptive feature for the ecological success of these epidemic clones/serotypes and alerts for global strategies to reduce arsenic-based compounds' impact thus preventing environmental/food contamination with frequent MDR foodborne pathogens.


Assuntos
Farmacorresistência Bacteriana Múltipla/genética , Óperon/genética , Salmonella/efeitos dos fármacos , Salmonella/genética , Animais , Arsênio/toxicidade , Células Clonais , Cobre/toxicidade , Poluentes Ambientais/toxicidade , Genótipo , Fenótipo , Reação em Cadeia da Polimerase , Infecções por Salmonella/microbiologia , Sorogrupo , Suínos
10.
Glob Chang Biol ; 26(12): 6767-6786, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32885894

RESUMO

Climate warming is rapidly reshaping the Arctic cryosphere and ocean conditions, with consequences for sea ice and pelagic productivity patterns affecting the entire marine food web. To predict how ongoing changes will impact Arctic marine ecosystems, concerted effort from various disciplines is required. Here, we contribute multi-decadal reconstructions of changes in diatom production and sea-ice conditions in relation to Holocene climate and ocean conditions off northwest Greenland. Our multiproxy study includes diatoms, sea-ice biomarkers (IP25 and HBI III) and geochemical tracers (TOC [total organic carbon], TOC:TN [total nitrogen], δ13 C, δ15 N) from a sediment core record spanning the last c. 9,000 years. Our results suggest that the balance between the outflow of polar water from the Arctic, and input of Atlantic water from the Irminger Current into the West Greenland Current is a key factor in controlling sea-ice conditions, and both diatom phenology and production in northeastern Baffin Bay. Our proxy record notably shows that changes in sea-surface conditions initially forced by Neoglacial cooling were dynamically amplified by the shift in the dominant phase of the Arctic Oscillation (AO) mode that occurred at c. 3,000 yr BP, and caused drastic changes in community composition and a decline in diatom production at the study site. In the future, with projected dominant-positive AO conditions favored by Arctic warming, increased water column stratification may counteract the positive effect of a longer open-water growth season and negatively impact diatom production.


Assuntos
Ecossistema , Camada de Gelo , Regiões Árticas , Cadeia Alimentar , Groenlândia
11.
Reprod Health ; 16(1): 140, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31511027

RESUMO

BACKGROUND: The existing knowledge on the interplay between reproductive and sexual health, migration and acculturation is recent and inconsistent, particularly on the sociocultural motives and constraints regarding fertility. Therefore, sexual and reproductive health (SRH) surveys are needed to provide accurate and comparable indicators to identify and address SRH inequalities, with specific focus on under researched aspects, such as the interrelation between migration and gender. FEMINA (FErtility, MIgratioN and Acculturation) aims to investigate intersectional SRH inequalities among Cape Verdean immigrant and Portuguese native families and how they impact on fertility in Portugal. This study will use a comprehensive approach exploring simultaneously the components of SRH, namely regarding identities, perceptions and practices of both women and men among lay people and relevant experts and stakeholders. The project has three main goals: 1) to identify social determinants of SRH among Cape Verdean immigrant and Portuguese native men and women of reproductive age; 2) to gain understanding of the diversity of the sexual and reproductive experiences and expectations of Cape Verdean immigrant and Portuguese native men and women of reproductive age, considering the singularities of their migratory, social and family dynamics; and 3) to produce recommendations for policy makers, employers and service providers on how to better address the SRH needs of Portuguese-born and immigrant populations. METHODS: The study will address these goals using a mixed methods approach, including: a cross-sectional telephone survey with a probabilistic sample of 600 Cape Verdean immigrant and 600 Portuguese native women and men (women aged 18 to 49 and men aged 18 to 54), residents of the Greater Lisbon Area; a qualitative research through in-depth interviews with a subsample of 30 Cape Verdean immigrants and 30 Portuguese native men and women; and a Delphi technique for finding consensus on good practices in SRH for the entire population with a special emphasis on immigrants, namely extra-EU migrants. DISCUSSION: Data will be used to produce a comprehensive set of indicators to monitor SRH in Portugal, to foster a greater understanding of its specificities and challenges to policy and decision makers, and to provide targeted recommendations to promote inclusive and migrant sensitive SRH services.


Assuntos
Aculturação , Fertilidade , Conhecimentos, Atitudes e Prática em Saúde , Saúde Reprodutiva/estatística & dados numéricos , Saúde Sexual/estatística & dados numéricos , Fatores Socioeconômicos , Migrantes/estatística & dados numéricos , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
12.
J Mater Sci Mater Med ; 29(8): 129, 2018 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-30066293

RESUMO

The 4th Translational Research Symposium (TRS) was organised at the annual meeting of the European Society for Biomaterials (ESB) 2017, Athens, Greece, with a focus on 'Academia-Industry Clusters of Research for Innovation Catalysis'. Collaborations between research institutes and industry can be sustained in several ways such as: European Union (EU) funded consortiums; syndicates of academic institutes, clinicians and industries; funding from national governments; and private collaborations between universities and companies. Invited speakers from industry and research institutions presented examples of these collaborations in the translation of research ideas or concepts into marketable products. The aim of the present article is to summarize the key messages conveyed during these lectures. In particular, emphasis is put on the challenges to appropriately identify and select unmet clinical needs and their translation by ultimately implementing innovative and efficient solutions achieved through joint academic and industrial efforts.


Assuntos
Materiais Biocompatíveis , Pesquisa Translacional Biomédica , Indústria Farmacêutica , Setor de Assistência à Saúde , Humanos , Apoio à Pesquisa como Assunto
13.
J Sex Marital Ther ; 43(8): 760-773, 2017 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-27911184

RESUMO

Few studies explore the clinicians' knowledge, attitudes, and practices regarding sexuality, despite their role in the sexual-health socialization process. This study focuses on Portuguese sexologists engaged in clinical practice. It aims to characterize sexologists' sex education and training and their clinical practices, including diagnostic and therapeutic approaches. This research followed the methodology of an European survey on sexology as a profession (Euro-Sexo). From the 91 respondents who completed questionnaires, 51 (56%) were active in clinical practice. Results indicate that the Portuguese clinical sexologist is significantly older, predominantly male, has had training in sexology, performs more scientific research, and is more engaged in teaching activities when compared to nonclinical working sexologists. This article describes the main sexual problems presented by patients to Portuguese clinical sexologists and highlights differences in the professional groups and approaches toward treating these problems by medical doctors and nonmedical professionals. Results reinforce the idea that there are intra-European differences in the educational background of sexologists and reveal important variations in Portuguese sexologists' education, training, and clinical practice. The representations and practices of the sexologists in Portugal, as in other European countries, are embedded in cultural scenarios and sexual cultures, with implications for the clinical practice.


Assuntos
Competência Clínica , Conhecimentos, Atitudes e Prática em Saúde , Relações Médico-Paciente , Educação Sexual/métodos , Sexologia/métodos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Papel do Médico , Portugal
14.
Eur J Public Health ; 27(suppl_4): 40-43, 2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-29028231

RESUMO

If public health is the field that diagnoses and strives to cure social ills, then understanding political causes and cures for health problems should be an intrinsic part of the field. In this article, we argue that there is no support for the simple and common, implicit model of politics in which scientific evidence plus political will produces healthy policies. Efforts to improve the translation of evidence into policy such as knowledge transfer work only under certain circumstances. These circumstances are frequently political, and to be understood through systematic inquiry into basic features of the political economy such as institutions, partisanship and the organization of labour markets.


Assuntos
Política de Saúde , Política , Saúde Pública , Europa (Continente) , Medicina Baseada em Evidências , Humanos , Formulação de Políticas , Política Pública
17.
J Mater Sci Mater Med ; 28(6): 87, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28470445

RESUMO

The integration and evolution of implantable medical devices made of bioresorbable polymers and used for temporary biomedical applications are crucial criteria in the success of a therapy and means of follow-up after implantation are needed. The objective of this work is to develop and evaluate a method based on microscopic Fourier Transform InfraRed spectroscopy (FTIR) mappings to monitor the degradation of such polymers on tissue explant sections, after implantation. This technique provided information on their location and on both their composition and crystallinity, which is directly linked to their state of degradation induced predominantly by chain scissions. An in vitro study was first performed on poly(L-lactic acid) (PLLA) meshes to validate the procedure and the assumption that changes observed on FTIR spectra are indeed a consequence of degradation. Then, mappings of in vivo degraded PLLA meshes were realized to follow up their degradation and to better visualize their degradation mechanisms. This work further warrants its translation to medical implants made of copolymers of lactic acid and to other polyesters.


Assuntos
Implantes Absorvíveis , Poliésteres/química , Espectroscopia de Infravermelho com Transformada de Fourier , Animais , Materiais Biocompatíveis , Equipamentos e Provisões , Masculino , Coelhos
18.
Phytother Res ; 31(10): 1571-1578, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28816369

RESUMO

The emergence of antimicrobial resistant infectious diseases remains a major threat to worldwide public health, in developed and in developing countries. Therefore, new antimicrobial agents acting by new mechanisms of action are urgently needed. As plants used in traditional medicine may help to overcome these problems, Justicia subsessilis, Platostoma rotundifolium, Pavetta ternifolia, Stomatanthes africanus, and Virectaria major (plants highly cited to be used against microbial infections in traditional Burundian medicine) were studied to assess their traditional use efficacy. We conducted a preliminary phytochemical screening of the extracts, as well as their direct and indirect (effect on antibiotic resistance) antibacterial activity on four bacterial strains (Staphylococcus sp. and Escherichia coli) by broth microdilution methods. All five medicinal plants investigated in this work were found to have direct antibacterial activity against all tested bacterial strains (minimum inhibitory concentration = 62.5-1000 µg/mL) that may support the use of these species in traditional Burundian medicine. Extracts (with no direct antibacterial activity), tested at 200 µg/mL, decreased the MIC values of ß-lactams and aminoglycoside antibiotics by a factor of 2 to 64-fold. These interactions between plant extracts and antibiotics could open an avenue of research against antibiotic resistance. Copyright © 2017 John Wiley & Sons, Ltd.


Assuntos
Anti-Infecciosos/farmacologia , Medicina Tradicional , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Antibacterianos/farmacologia , Asteraceae/química , Burundi , Escherichia coli/efeitos dos fármacos , Humanos , Lamiaceae/química , Testes de Sensibilidade Microbiana
19.
Int J Mol Sci ; 18(6)2017 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-28613253

RESUMO

Platostoma rotundifolium (Briq.) A. J. Paton aerial parts are widely used in Burundi traditional medicine to treat infectious diseases. In order to investigate their probable antibacterial activities, crude extracts from P. rotundifolium were assessed for their bactericidal and anti-virulence properties against an opportunistic bacterial model, Pseudomonas aeruginosa PAO1. Whereas none of the tested extracts exert bacteriostatic and/or bactericidal proprieties, the ethyl acetate and dichloromethane extracts exhibit anti-virulence properties against Pseudomonas aeruginosa PAO1 characterized by an alteration in quorum sensing gene expression and biofilm formation without affecting bacterial viability. Bioguided fractionation of the ethyl acetate extract led to the isolation of major anti-virulence compounds that were identified from nuclear magnetic resonance and high-resolution molecular spectroscopy spectra as cassipourol, ß-sitosterol and α-amyrin. Globally, cassipourol and ß-sitosterol inhibit quorum sensing-regulated and -regulatory genes expression in las and rhl systems without affecting the global regulators gacA and vfr, whereas α-amyrin had no effect on the expression of these genes. These terpenoids disrupt the formation of biofilms at concentrations down to 12.5, 50 and 50 µM for cassipourol, ß-sitosterol and α-amyrin, respectively. Moreover, these terpenoids reduce the production of total exopolysaccharides and promote flagella-dependent motilities (swimming and swarming). The isolated terpenoids exert a wide range of inhibition processes, suggesting a complex mechanism of action targeting P. aeruginosa virulence mechanisms which support the wide anti-infectious use of this plant species in traditional Burundian medicine.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Lamiaceae/química , Pseudomonas aeruginosa/efeitos dos fármacos , Percepção de Quorum/efeitos dos fármacos , Terpenos/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Humanos , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/fisiologia , Terpenos/química , Terpenos/isolamento & purificação , Fatores de Virulência/genética
20.
Mycopathologia ; 181(1-2): 145-9, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26369644

RESUMO

We report an atypical case of Rhodotorula mucilaginosa fungemia coexisting with pleural tuberculosis, in an immunocompetent host. The patient was an inhaled drug abuser and worked in a fruit market. The diagnosis of Rhodotorula mucilaginosa infection was established by the isolation of the yeast in two blood cultures followed by a good response to amphotericin B treatment. Persistent evening fever and pleural effusion led to the second diagnosis-pleural tuberculosis. In the last 5 years, this was the only case of Rhodotorula mucilaginosa fungemia in our hospital and the first case in the literature that documents Rhodotorula mucilaginosa fungemia associated with pleural tuberculosis.


Assuntos
Fungemia/complicações , Fungemia/diagnóstico , Rhodotorula/isolamento & purificação , Tuberculose Pleural/complicações , Tuberculose Pleural/diagnóstico , Adulto , Anfotericina B/administração & dosagem , Antifúngicos/administração & dosagem , Sangue/microbiologia , Fungemia/patologia , Humanos , Masculino , Resultado do Tratamento , Tuberculose Pleural/patologia
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