132 research outputs found

    Life Strategies, Ecology, and Risks in a Changing Environment

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    UIDB/CVT/00772/2020. Publisher Copyright: © 2022 by the authors.Vibrios are ubiquitous bacteria in aquatic systems, especially marine ones, and belong to the Gammaproteobacteria class, the most diverse class of Gram-negative bacteria. The main objective of this review is to update the information regarding the ecology of Vibrio species, and contribute to the discussion of their potential risk in a changing environment. As heterotrophic organisms, Vibrio spp. live freely in aquatic environments, from marine depths to the surface of the water column, and frequently may be associated with micro- and macroalgae, invertebrates, and vertebrates such as fish, or live in symbiosis. Some Vibrio spp. are pathogenic to humans and animals, and there is evidence that infections caused by vibrios are increasing in the world. This rise may be related to global changes in human behavior (increases in tourism, maritime traffic, consumption of seafood, aquaculture production, water demand, pollution), and temperature. Most likely in the future, Vibrio spp. in water and in seafood will be monitored in order to safeguard human and animal health. Regulators of the microbiological quality of water (marine and freshwater) and food for human and animal consumption, professionals involved in marine and freshwater production chains, consumers and users of aquatic resources, and health professionals will be challenged to anticipate and mitigate new risks.publishersversionpublishe

    Antimicrobial activity of essential oils from mediterranean aromatic plants against several foodborne and spoilage bacteria

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    The antimicrobial activity of essential oils extracted from a variety of aromatic plants, often used in the Portuguese gastronomy was studied in vitro by the agar diffusion method. The essential oils of thyme, oregano, rosemary, verbena, basil, peppermint, pennyroyal and mint were tested against Gram-positive (Listeria monocytogenes, Clostridium perfringens, Bacillus cereus, Staphylococcus aureus, Enterococcus faecium, Enterococcus faecalis, and Staphylococcus epidermidis) and Gram-negative strains (Salmonella enterica, Escherichia coli, and Pseudomonas aeruginosa). For most essential oils examined, S. aureus, was the most susceptible bacteria, while P. aeruginosa showed, in general, least susceptibility. Among the eight essential oils evaluated, thyme, oregano and pennyroyal oils showed the greatest antimicrobial activity, followed by rosemary, peppermint and verbena, while basil and mint showed the weakest antimicrobial activity. Most of the essential oils considered in this study exhibited a significant inhibitory effect. Thyme oil showed a promising inhibitory activity even at low concentration, thus revealing its potential as a natural preservative in food products against several causal agents of foodborne diseases and food spoilage. In general, the results demonstrate that, besides flavoring the food, the use of aromatic herbs in gastronomy can also contribute to a bacteriostatic effect against pathogens

    Effect of phenolic compounds extracted from chestnut (Castanea sativa Mill) industry by-products on antibiotic resistant bacteria

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    In the last years, antibiotic resistance has become a selious threat tohuman and animal health since a large number of microorganisms have developed resistance to the drugs commonly used.Several natural compounds have been gcttingincreased attention as alternatives to many drugs. Phenolic compounds are secondary metabolites which exhibit several properties, such as, antimicrobial. antioxidant, anti-inflammatory, antimutagentic and cardioprotective. Thus, this study aims to investigate the antibacterial properties of the iJhenolic compounds extracted from the chestnut (Castaneasativa Mill.) industry by-products !gains! antibiotic resistant bacteria.info:eu-repo/semantics/publishedVersio

    A Decade-Long Commitment to Antimicrobial Resistance Surveillance in Portugal

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    Antimicrobial resistance (AMR) is a worldwide problem with serious health and economic repercussions. Since the 1940s, underuse, overuse, and misuse of antibiotics have had a significant environmental downside. Large amounts of antibiotics not fully metabolized after use in human and veterinary medicine, and other applications, are annually released into the environment. The result has been the development and dissemination of antibiotic-resistant bacteria due to many years of selective pressure. Surveillance of AMR provides important information that helps in monitoring and understanding how resistance mechanisms develop and disseminate within different environments. Surveillance data is needed to inform clinical therapy decisions, to guide policy proposals, and to assess the impact of action plans to fight AMR. The Functional Genomics and Proteomics Unit, based at the University of Trás-os-Montes and Alto Douro (UTAD) in Vila Real, Portugal, has recently completed 10 years of research surveying AMR in bacteria, mainly commensal indicator bacteria such as enterococci and Escherichia coli from the microbiota of different animals. Samples from more than 75 different sources have been accessed, from humans to food-producing animals, pets, and wild animals. The typical microbiological workflow involved phenotypic studies followed by molecular approaches. Throughout the decade, 4,017 samples were collected and over 5,000 bacterial isolates obtained. High levels of AMR to several antimicrobial classes have been reported, including to β-lactams, glycopeptides, tetracyclines, aminoglycosides, sulphonamides and quinolones. Multi-resistant strains, some relevant to human and veterinary medicine like extended-spectrum β-lactamase-producing E. coli and vancomycin-resistant enterococci, have been repeatedly isolated even in non-synanthropic animal species. Of particular relevance are reports of AMR bacteria in wildlife from natural reserves and endangered species. Future work awaits as this threatening yet unsolved problem persists

    Chemical composition of different oregano (origanum vulgare l.) essential oils: relevance for the activity against foodborne and spoilage bacteria

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    Herbs and spices have been used for centuries in culinary for seasoning and flavouring purposes. More recently, there has been a growing interest regarding the use of some plants and its essential oils (EO) for their activity against foodborne pathogens and foodspoilage bacteria. Due to its potential in extending the self-life of foods and its better acceptability by consumers who demand more “natural” foods, the use of EO can be an interesting alternative to substitute, at least partially, synthetic preservatives

    Review of structural features and binding capacity of polyphenols to gluten proteins and peptides in vitro: Relevance to celiac disease

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    UIDB 50006/2020 UID/AGR/04033/2019 project-POCI-01-0145-FEDER-029068Polyphenols have been extensively studied due to their beneficial effects on human health, particularly for the prevention and treatment of diseases related to oxidative stress. Nevertheless, they are also known to have an anti-nutritional effect in relation to protein metabolism. This effect is a consequence of its binding to digestive enzymes and/or protein substrates. Dietary gluten is the main trigger of celiac disease, a common immune-based disease of the small intestine and for which the only treatment available is the adherence to a gluten-free diet. Recent studies have addressed the use of dietary polyphenols to interact with gluten proteins and avoid its downstream deleterious effects, taking the advantage of the anti-nutritive nature of polyphenols by protein sequestering. Flavonoids, coumarins and tannins have shown the ability to form insoluble complexes with gluten proteins. One of the most promising molecules has been epigallocatechin-3-gallate, which through its binding to gliadins, was able to reduce gliadins digestibility and its ability to stimulate monolayer permeability and transepithelial transport of immunodominant peptides in cell models. This review focuses on the structural features and binding capacity of polyphenols to gluten proteins and peptides, and the prospects of developing an adjuvant therapy in celiac disease.publishersversionpublishe

    drawing parallels to the infection in human medicine

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    Publisher Copyright: © 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This research received no external fundingOsteomyelitis is a challenging infectious disease affecting humans and animals. It is difficult to diagnose because, in many cases, symptoms are non-specific and, for example in implant-related cases, can appear long time after surgery. In addition to this, it is also difficult to treat due to the need to find the appropriate antibiotic regime and delivery system to reach the site of infection and to avoid development of bacterial resistance. The central purpose of this review is to compare the microbiological aspects of osteomyelitis in human and veterinary medicine, with the aim of improving the microbiological diagnosis and treatment of this infection in animals. Furthermore, the study of osteomyelitis in animals may help to improve the development of animal models for testing new treatments in humans. Host factors and underlying conditions have been studied mainly in humans, although aspects as immunodeficiency have been described in some veterinary cases. Even when Staphylococcus aureus is still considered the most prevalent causing microorganism, this prevalence should be reviewed using molecular diagnostic techniques, and this could affect treatment options. New approaches to treatment include local delivery of antibiotics using different biomaterials, antimicrobial photodynamic therapy, and new antimicrobial compounds. We would like to remark the need of large, high-quality clinical trials and of the development of guides for the diagnosis and treatment of osteomyelitis in different animal species.publishersversionpublishe

    Multilocus Sequence Typing for characterization of potential risk ESBLs-producing Escherichia coli isolated from pigs, including strains of new singletons ST2528, ST2524 and ST2525

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    Infections caused by Escherichia coli harboring extended-spectrum beta-lactamases (ESBL) have a tremendous impact on public health, because of treatment complications. ESBL-producing E. coli are increasingly reported in healthy food-producing animals that can spread to humans either by direct contact or, more importantly, through the food chain. Here we describe a molecular survey aimed at determining the population structure and dynamics of ESBL-producing E. coli strains recovered from healthy pigs slaughtered for human consumption in Portugal. For this purpose, a total of 71 faecal samples from pigs were collected (2008 to 2009) in different geographical regions of Portugal. Susceptibility to 16 antibiotics was tested by disk-diffusion method in all recovered isolates and ESBL detection was carried out by double-disk test. PCR and sequencing methods characterized blaESBL genes responsible for the ESBL-phenotype. In addition, we used multilocus sequence typing (MLST) to identify the genetic lineages of all ESBL-producing E. coli strains, which were characterized by sequencing the internal fragments of 7 housekeeping genes (adk, fumC, gyrB, icd, mdh, purA, recA); the MLST database was used to determine allelic profiles and for sequence type (ST) and clonal complex (CC) assignment. Among the 35 ESBL-producing strains, MLST analysis revealed 9 different STs under 6 CCs and 9 singletons STs. The CC10 and CC155 were the most common CCs, with 4 and 11 isolates, respectively. Two other isolates were assigned to the CC101. Moreover, 5 strains were included in 3 new STs; 3 of them were identified in a new allele for the fumC gene that originated the new ST2528; in addition, 2 isolates were registered as ST2524 and ST2525 through new combination of alleles. Through the MLST database we found that ST656 (CC10) and ST8 (CC165) have a higher homology to ST2524 and ST2525, respectively. However, by the definition of CCs, ST2524 and ST2525 most likely belong to CC10 and CC165, respectively. Our data shows the presence of ESBL producing E. coli isolates in pigs slaughtered for human consumption and raises important questions in the potential risk factors to public health due to the transmission of bacteria carrying resistance through the food chain, and spreading resistance to other bacteria of human clinical significance. A great heterogeneity of MLST types was observed, among which CC10, CC155 and CC101 have already been associated with human clinical isolates
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