Probiotic potential of leuconostoc lactis rk18 isolated from fermented food and its bacteriocinogenic activity against foodborne pathogens

Fermentation is one of the oldest techniques for the production of foods. Lactic acid bacteria (LAB) have been progressively used in food industry since, besides improving nutritional and technological features, they also contribute to the safety of food products. Consequently, this work aimed to isolate lactic acid bacteria from several food products and to evaluate their potential antimicrobial activity and probiotic characteristics. From 202 LAB isolated from 20 fermented food products, only three isolates were selected and identified as Enterococcus faecium RS7 (fermented shrimp), Enterococcus faecium P12 (pork sausage) and Leuconostoc lactis RK18 (khmer fermented rice fresh noodles) based on their antimicrobial activity against Enterococcus faecalis and Listeria monocytogenes strains. These selected isolates were further tested for probiotic characteristics. Despite the beneficial characteristics apparently presented by the three isolates due to their antimicrobial activity, only Ln. lactis RK18 met the safety requirement and therefore it was the only isolate selected for further tests. Leuconostoc lactis RK18 did not present any of the virulence factors nor virulence genes tested (with exception of aggregation substance protein gene asa1), and it was also susceptible to all antibiotics recommended by European Food Safety Authority. Regarding beneficial characteristics, it was found that anti-listerial activity of Ln. lactis RK18 was due to the production of a Class IIa bacteriocin (<6.5 kDa in size), which remained stable at average temperatures (30 ºC to 80 ºC) and at pH values ranging from 4 to 6, and although susceptible to some detergents, it showed greatly resistance to several enzymes. Despite being very sensitive to acidic environments, when incorporated into a complex food matrix such as alheira, Ln. lactis RK18 was able to survive through simulated gastrointestinal tract (GIT) conditions and also to adhere (but not invade) to human colon adenocarcinoma cell lines Caco-2 in vitro. Even though exposure to GIT conditions had influenced the adhesion ability of Ln. lactis RK18 cells, this potential probiotic and merely 10% of its treated cell-free supernatant, were able to prevent the ability of L. monocytogenes CEP 104794 to adhere and invade Caco-2 cells. Overall, Ln. lactis RK18 appeared to be a safe strain, with no risk to human health, which harbored important features to be successfully considered as a potential biopreservative and probiotic culture. Nevertheless, further experiments should be performed for the validation of its application in the food industry.A fermentação é uma das mais antigas técnicas na produção de alimentos. As bactérias do ácido lático (BAL) têm sido muito usadas na indústria alimentar, uma vez que melhoram as características nutricionais e tecnológicas, e contribuem para a segurança dos alimentos. Assim, o objetivo deste trabalho foi o isolamento de BAL de vários alimentos e de avaliar a sua potencial atividade antimicrobiana e características probióticas. De 202 BAL isoladas de 20 alimentos fermentados, apenas três isolados foram selecionados e identificados como Enterococcus faecium RS7 (camarão fermentado), Enterococcus faecium P12 (linguiça de porco) e Leuconostoc lactis RK18 (khmer “noodles” de arroz fermentado fresco), seleção essa baseada na sua atividade antimicrobiana contra estirpes de Enterococcus faecalis e Listeria monocytogenes. Os isolados selecionados foram testados quanto a características probióticas. Apesar da atividade antimicrobiana apresentada pelos três isolados, apenas Ln. lactis RK18 preencheu o requisito de segurança e, portanto, foi o único isolado selecionado para outros testes. Leuconostoc lactis RK18 não apresentou nenhum dos fatores ou genes de virulência testados (exceto o gene da proteína de substância de agregação asa1), e também foi suscetível a todos os antibióticos recomendados pela Autoridade Europeia de Segurança Alimentar. Relativamente às características benéficas, a atividade anti-listeria de Ln. lactis RK18 foi devida à produção de uma bacteriocina Classe IIa (tamanho <6,5 kDa), a qual permaneceu estável a temperaturas moderadas (30 ºC a 80 ºC) e em valores de pH entre 4 a 6 e, embora sensível a alguns detergentes, apresentou grande resistência a várias enzimas. Apesar de muito sensível a ambientes ácidos, quando incorporado numa matriz alimentar complexa como a alheira, Ln. lactis RK18 sobreviveu às condições simuladas do trato gastrointestinal (TGI) e aderiu (mas não invadiu) às linhas celulares de adenocarcinoma do cólon humano Caco-2 in vitro. Embora a exposição às condições do TGI tenha influenciado a capacidade de adesão de Ln. lactis RK18, este potencial probiótico e apenas 10% do seu sobrenadante, preveniram a adesão e invasão de células intestinais por L. monocytogenes CEP 104794. Em conclusão, Ln. lactis RK18 parece ser uma estirpe sem risco para a saúde humana, com características importantes que a tornam uma potencial cultura bioconservante e probiótica. No entanto, mais experiências devem ser realizadas para a validação da sua aplicação na indústria alimentar

The establishment of a humanitarian assistance force in the CPLP : challenges and opportunities to the defense cooperation

Lusíada. Política Internacional e Segurança. - ISSN 1647-1342. - S. 1, n. 23-24 (2022). - p. ....-...

Perceções em torno dos incêndios florestais no concelho de Trancoso

Ao longo dos anos, o clima tem vindo a alterar-se e são cada vez mais notórias as suas consequências; os incêndios florestais, que são, há décadas, um grave problema a nível ambiental, social e económico, são um exemplo. Os incêndios têm diversas causas associadas, e apesar de serem sazonais, o que se tem observado, devido, em grande medida, às alterações climáticas, é o alargamento do período em que ocorrem, um maior número de incêndios e uma maior velocidade de propagação. A intervenção humana é muito importante e pode representar um papel decisivo tanto na origem dos incêndios, como na sua evolução e extinção. Para atenuar algumas das consequências das alterações climáticas torna-se essencial apostar em medidas de mitigação e de adaptação. O objetivo desta dissertação é captar o modo como os indivíduos percecionam, experienciam e reagem aos fogos florestais no concelho de Trancoso. Optou-se nesta investigação pela metodologia qualitativa e recorreu-se à técnica de entrevistas semiestruturadas. A amostra contempla Presidentes de Junta de Freguesia, bombeiros e indivíduos com características sociodemográficas diversificadas.Over the years, the climate has been changing and its consequences are increasingly notorious; forest fires, which have been a serious environmental, social, and economic problem for decades, are an example. Fires have several associated causes, and although they are seasonal, what has been observed largely due to climate change is the extension of the period in which they occur, a greater number of fires and a greater speed of propagation. Human intervention is very important and can play a decisive role both in the origin of fires and in their evolution and extinction. To attenuate some of the consequences of climate change, it is essential to focus on mitigation and adaptation measures. The aim of this dissertation is to capture how individuals perceive, experience and react to forest fires in the municipality of Trancoso. In this research, it was chosen the qualitative methodology and it was used the technique of semi-structured interviews. The sample includes Parish Council Presidents, firefighters and individuals with several sociodemographic characteristics

Novos fármacos no sarcoma de Ewing

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2016Os doentes com Sarcoma de Ewing (EWS), neoplasia maligna mesenquimatosa caracterizada pela translocação específica t(11;22) e pela proteína de fusão EWSR1-FLI1, não têm tido um aumento muito significativo da sua sobrevivência nos últimos anos apesar dos avanços científicos. A terapêutica consiste na cirurgia e/ou radioterapia, sendo sempre recomendada quimioterapia antes e após as técnicas de controlo local. A escolha do tratamento local depende da possibilidade de excisão com margens seguras, da potencial perda funcional e do tamanho tumoral, entre outros fatores. Neste estudo pretende-se fazer uma revisão da literatura sobre este subtipo de sarcoma, dando particular relevo à quimioterapia e novas terapêuticas-alvo. Os esquemas de quimioterapia têm vindo a ser alterados ao longo dos anos, de acordo com os resultados dos ensaios clínicos. Atualmente, os principais esquemas utilizam vincristina, ifosfamida, doxorrubicina, etoposido, dactinomicina e ciclofosfamida, em combinações e sequências diferentes. A investigação da biologia molecular e celular do EWS levou à descoberta de potenciais alvos terapêuticos. Vários fármacos dirigidos a estes alvos estão a ser investigados, alguns já em ensaios clínicos, outros apenas com estudos pré-clínicos realizados. Está também a ser pesquisada a presença de biomarcadores que permitam prever a resposta terapêutica. Alguns destes fármacos, como por exemplo, os fármacos anti-IGF-1R, têm mostrados resultados muito promissores, mas aguardam-se mais estudos.Ewing sarcoma (EWS) is a mesenquimatous malignant neoplasm characterized by the specific translocation t(11;22) and by the fusion protein EWSR1-FLI1. Patients with EWS have not had a significant increase in their overall survival in these last years, despite increasing investigation. Treatment is based on chemotherapy before and after local control approaches, that is, surgery and/or radiotherapy. The choice of the most appropriate local treatment depends on the tumor size, the probability to obtain negative margins and the potential functional loss, among other factors. This study intends to review the literature on this subtype of sarcoma, with particular regard to chemotherapy and targeted therapies. The chemotherapy regimens have changed over the years, following the results of clinical trials. Currently, the main chemotherapy regimens use vincristine, ifosfamide, doxorubicin, etoposide, cyclophosphamide, and dactinomycin, in different combinations and sequences. Basic research on the molecular and cellular biology of EWS has led to the discovery of potential therapeutic targets. Several drugs directed at these targets are currently under investigation. While some of them are already being tested in clinical trials, others have only now completed preclinical studies. Several potential biomarkers are also being evaluated to predict response to therapy. Some of these drugs, such as anti-IGF-1R drugs have shown promising results, but further studies are still needed

Osteosarcoma pathogenesis leads the way to new target treatments

© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).Osteosarcoma (OS) is a rare condition with very poor prognosis in a metastatic setting. Basic research has enabled a better understanding of OS pathogenesis and the discovery of new potential therapeutic targets. Phase I and II clinical trials are already ongoing, with some promising results for these patients. This article reviews OS pathogenesis and new potential therapeutic targets.info:eu-repo/semantics/publishedVersio

Optimization of HS-SPME analytical conditions using factorial design for trihalomethanes determination in swimming pool water samples

Trihalomethanes (THMs) are widely referred and studied as disinfection by-products (DBPs). The THMs that are most commonly detected are chloroform (TCM), bromodichloromethane (BDCM), chlorodibromomethane (CDBM), and bromoform (TBM). Several studies regarding the determination of THMs in swimming pool water and air samples have been published. This paper reviews the most recent work in this field, with a special focus on water and air sampling, sample preparation and analytical determination methods. An experimental study has been developed in order to optimize the headspace solid-phasemicroextraction (HS-SPME) conditions of TCM, BDCM, CDBM and TBM from water samples using a 23 factorial design. An extraction temperature of 45 °C, for 25min, and a desorption time of 5 min were found to be the best conditions. Analysis was performed by gas chromatography with an electron capture detector (GC-ECD). The method was successfully applied to a set of 27 swimming pool water samples collected in the Oporto area (Portugal). TCM was the only THM detected with levels between 4.5 and 406.5 μg L−1. Four of the samples exceeded the guideline value for total THMs in swimming pool water (100 μgL−1) indicated by the Portuguese Health Authority

Characterisation of physiological responses to odours in autism spectrum disorders: a preliminary study

Abnormal sensory perception is among the earliest symptoms of autism spectrum disorders (ASD). Despite mixed findings, olfactory perception seems to be altered in ASD. There is also evidence that automatic responses to odours can serve as biomarkers of ASD. However, this potential use of odour-based biomarkers for ASD is still underexplored. In this study, we aimed to investigate whether physiological responses to social and non-social odours, measured with electrocardiography (ECG) and facial electromyography (EMG), can be used to characterise and predict ASD in adults. For that, we extracted 32 signal features from a previously collected database of 11 adults with ASD and 48 adults with typical development (TD). Firstly, non-parametric tests were performed, showing significant differences between the ASD and the TD groups in 10 features. Secondly, a k-nearest-neighbour classifier with a leave-one-out strategy was employed, obtaining an F1-score of 67%. Although caution is needed due to the small sample size, this study provides preliminary evidence supporting the use of physiological responses to social and non-social odours as a potential diagnostic tool for ASD in adults.This work is also funded by national funds, European Regional Development Fund, FSE through COMPETE2020, through FCT, in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19.publishe

Vaccination Controversies: An Adult Case of Post-Vaccinal Acute Disseminated Encephalomyelitis

Acute disseminated encephalomyelitis is a rare inflammatory demyelinating multifocal disease of the central nervous system that typically occurs in children following vaccination or exanthematous viral infections and conveys an elevated risk of neurological sequelae unless promptly recognized and treated. We describe an adult case of acute disseminated encephalomyelitis following vaccination against Mumps, Measles and Rubella, presenting with fever and progressive neurological deficits which improved under systemic corticosteroid therapy. Considering the ongoing public debate regarding universal vaccination and the surge of previously controlled infectious diseases, we aim not only to underline the need for a rigorous assessment of vaccination safety on adult patients in order to prevent misguidance of public opinion, but also to alert clinicians for an early diagnosis of acute disseminated encephalomyelitis in these patients, the incidence of which we speculate may be rising