8 research outputs found

    Antimicrobial metallic copper surfaces kill Staphylococcus haemolyticus via membrane damage

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    Recently, copper (Cu) in its metallic form has regained interest for its antimicrobial properties. Use of metallic Cu surfaces in worldwide hospital trials resulted in remarkable reductions in surface contaminations. Yet, our understanding of why microbes are killed upon contact to the metal is still limited and different modes of action have been proposed. This knowledge, however, is crucial for sustained use of such surfaces in hospitals and other hygiene-sensitive areas. Here, we report on the molecular mechanisms by which the Gram-positive Staphylococcus haemolyticus is inactivated by metallic Cu. Staphylococcus haemolyticus was killed within minutes on Cu but not on stainless steel demonstrating the antimicrobial efficacy of metallic Cu. Inductively coupled plasma mass spectroscopy (ICP-MS) analysis and in vivo staining with Coppersensor-1 indicated that cells accumulated large amounts of Cu ions from metallic Cu surfaces contributing to lethal damage. Mutation rates of Cu- or steel-exposed cells were similarly low. Instead, live/dead staining indicated cell membrane damage in Cu- but not steel-exposed cells. These findings support a model of the cellular targets of metallic Cu toxicity in bacteria, which suggests that metallic Cu is not genotoxic and does not kill via DNA damage. In contrast, membranes constitute the likely Achilles’ heel of Cu surface-exposed cells

    Antimicrobial metallic copper surfaces kill Staphylococcus haemolyticus via membrane damage

    Get PDF
    Recently, copper (Cu) in its metallic form has regained interest for its antimicrobial properties. Use of metallic Cu surfaces in worldwide hospital trials resulted in remarkable reductions in surface contaminations. Yet, our understanding of why microbes are killed upon contact to the metal is still limited and different modes of action have been proposed. This knowledge, however, is crucial for sustained use of such surfaces in hospitals and other hygiene-sensitive areas. Here, we report on the molecular mechanisms by which the Gram-positive Staphylococcus haemolyticus is inactivated by metallic Cu. Staphylococcus haemolyticus was killed within minutes on Cu but not on stainless steel demonstrating the antimicrobial efficacy of metallic Cu. Inductively coupled plasma mass spectroscopy (ICP-MS) analysis and in vivo staining with Coppersensor-1 indicated that cells accumulated large amounts of Cu ions from metallic Cu surfaces contributing to lethal damage. Mutation rates of Cu- or steel-exposed cells were similarly low. Instead, live/dead staining indicated cell membrane damage in Cu- but not steel-exposed cells. These findings support a model of the cellular targets of metallic Cu toxicity in bacteria, which suggests that metallic Cu is not genotoxic and does not kill via DNA damage. In contrast, membranes constitute the likely Achilles’ heel of Cu surface-exposed cells

    Influence of storage conditions on fruit quality of ‘Royal Time’ and ‘Royal Summer’ peach cultivars

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    Peach is a very perishable climacteric fruit whose firmness may decay rapidly depending on the temperature. Refrigeration is usually used to delay ripening and maintain fruit quality. However, often temperature storage conditions are not optimized. This work aims to characterize the storage conditions (temperature and humidity) of three peach producers of Beira Interior region, Portugal. Additionally, correlate those conditions with peach quality evolution comparing two peach cultivars – Royal Summer and Royal Time – with similar harvest dates but very different acidity content. The three refrigeration chambers monitored have very distinct conditions of average air temperature, namely 8.29±3.53 °C (local C), 5.50±0.88 °C (local G) and 0.80±0.83 °C (local L) but similar high humidity, in an average range of 90%-98%. At harvest time, major differences were in fruit firmness and acidity. ‘Royal Summer’ firmness was 6.61 kgf and ‘Royal Time’ was 5.20 kgf. For all storage conditions, fruit firmness decrease faster for ‘Royal Time’ cultivar than for ‘Royal Summer’. The results suggest that in general farmers use inadequate range temperature for long storage period. For short periods of 7 days, conditions like those of local G allow fruit quality maintenance like firmness and loss of weight without problems of chilling injury, and, simultaneously, save energy that is also not only a desirable international goal but also contributes to decrease of production costs.O pêssego é um fruto climatérico, altamente perecível, cuja firmeza diminui rapidamente dependendo da temperatura de conservação. A refrigeração é o processo utilizado para atrasar a maturação e manter a qualidade embora, em muitos casos, a temperatura de refrigeração não seja otimizada. Este trabalho pretende caracterizar as condições de refrigeração (temperatura e humidade) das câmaras de três produtores de pêssego da Beira Interior. Adicionalmente, pretende também relacionar essas condições com a evolução da qualidade dos frutos utilizando duas cultivares – Royal Summer e Royal Time – com data de colheita semelhante, mas teor de acidez distinto. As três câmaras de refrigeração monitorizadas corresponderam a condições bastante diferentes de temperatura, nomeadamente, 8,29±3,53°C (local C), 5,50±0,88°C (local G) e 0,80±0,83°C (local L), mas semelhantes em termos de humidade, que está compreendida entre 90% e 98%. À colheita, as maiores diferenças observadas foram a firmeza e acidez. A firmeza dos pêssegos da ‘Royal Summer’ foi de 6,61 kgf e a da ‘Royal Time’ foi de 5,20 kgf. Para todas as condições de conservação, a firmeza diminuiu mais rapidamente na ‘Royal Time’. Os resultados sugerem que, em geral, os produtores usam intervalos de temperatura inadequados para períodos de conservação longos. Contudo, considerando períodos curtos, entre 7 dias, as condições observadas no local G permitiram manter a qualidade como firmeza e perda de peso, sem se observarem danos por frio. Simultaneamente, permitem economizar energia o que é um objetivo internacional e contribui para a diminuição dos custos de produção.This research work is part of project “PrunusPÓS – Otimização de processos de armazenamento, conservação em frio e embalamento inteligente no pós-colheita de pêssego e cereja”, n.º PDR2020-101-031695 (PDR 020), Portugal 2020. The authors would like to thank the producers who allowed the use of the refrigeration chambers and the respective monitoring of its conditions.info:eu-repo/semantics/publishedVersio

    Nutritional characterization of honey from the Beira Baixa Region

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    Honey is a natural, sweet viscous food produced by honeybees and other insects through regurgitation, enzymatic activity and water evaporation, to sustain the colony when flowers are not in season. Domestication of the Apis genera of the honeybees, lead Humans to better control the quality and the amount of honey production. Honey’s nutritional value is exceptional, due to the variety of carbohydrates, such as fructose, glucose, sucrose, maltose and other polysaccharides and oligosaccharides. Additionally, honey is composed of multiple vitamins, minerals, flavonoids, acids, and enzymes. Honey’s biological activity is quite known and studied for high antioxidant content, and for bactericidal and antiviral action. Honey is one of the most important food products made in the Beira Baixa Region. Here, we show the nutritional value of the Honey produced in neighbour cities in Beira Baixa’s region: Oleiros, Castelo Branco and Vila Velha de Rodão; with special focus on the carbohydrate composition compared between the type of honey.info:eu-repo/semantics/publishedVersio

    Gut Microbiota, in the Halfway between Nutrition and Lung Function

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    The gut microbiota is often mentioned as a "forgotten organ" or "metabolic organ", given its profound impact on host physiology, metabolism, immune function and nutrition. A healthy diet is undoubtedly a major contributor for promoting a "good" microbial community that turns out to be crucial for a fine-tuned symbiotic relationship with the host. Both microbial-derived components and produced metabolites elicit the activation of downstream cascades capable to modulate both local and systemic immune responses. A balance between host and gut microbiota is crucial to keep a healthy intestinal barrier and an optimal immune homeostasis, thus contributing to prevent disease occurrence. How dietary habits can impact gut microbiota and, ultimately, host immunity in health and disease has been the subject of intense study, especially with regard to metabolic diseases. Only recently, these links have started to be explored in relation to lung diseases. The objective of this review is to address the current knowledge on how diet affects gut microbiota and how it acts on lung function. As the immune system seems to be the key player in the cross-talk between diet, gut microbiota and the lungs, involved immune interactions are discussed. There are key nutrients that, when present in our diet, help in gut homeostasis and lead to a healthier lifestyle, even ameliorating chronic diseases. Thus, with this review we hope to incite the scientific community interest to use diet as a valuable non-pharmacological addition to lung diseases management. First, we talk about the intestinal microbiota and interactions through the intestinal barrier for a better understanding of the following sections, which are the main focus of this article: the way diet impacts the intestinal microbiota and the immune interactions of the gut-lung axis that can explain the impact of diet, a key modifiable factor influencing the gut microbiota in several lung diseases

    Technologies for monitoring the safety of perishable food products

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    Food safety and eradication of food waste are current concerns of society and governments due to health, ethics, and sustainable economics. There are multiple technologies for monitoring food safety at different chain stages, among them, time-temperature integrators (TTI). Temperature is a major factor affecting food quality and safety during its life cycle. This parameter can be monitored using TTI devices on food packages, allowing users to know the thermal exposure. This chapter addresses food safety issues, namely factors related to microbial growth responsible for food deterioration. Moreover, TTI monitoring technologies are also described, focusing on features, advantages, disadvantages, applicability, and product examples. Analysis of the current state of TTI and technological evolution, a prediction is provided for future TTI devices designed for more assertive, traceable, safe, and quality food products.info:eu-repo/semantics/publishedVersio

    Morphological, Molecular and Genomic Identification and Characterisation of <i>Monilinia fructicola</i> in <i>Prunus persica</i> from Portugal

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    In Portugal, the Cova da Beira region is well-known for the production of Prunus spp. and is considered the main peach production area in the country. In the spring of 2021 and 2022, field surveys in peach and nectarine orchards showed symptoms of decline such as cankers, gummosis, dry branches, abortion of flowers, mummified fruits and the partial or total death of some plants. Brown rot is caused by three species of the genus Monilinia, M. fructigena, M. laxa and M. fructicola, the last is an OEPP/EPPO A2 quarantine organism on peach trees. Brown rot disease had previously been described in the Cova da Beira region, however, the recent high mortality and severity of symptoms raised doubts as to the species involved. Symptomatic plant material was collected from thirteen orchards and used for fungal isolation and molecular detection according to the OEPP/EPPO standard. M. fructicola was confirmed morphologically and molecularly in two orchards, and molecularly (duplex real-time PCR) detected in two others. Whole genome sequencing using Oxford Nanopore MinION was also carried out to confirm the identification. Pathogenicity tests were performed on peach, nectarine and sweet cherry fruit according to Koch’s postulates. Based on all the results obtained, we report the first detection of M. fructicola in P. persica in Portugal
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