Browsing by Issue Date, starting with "2017"
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- Diagnóstico pré-natal citogenética convencional/ citogenómicaPublication . Correia, HildebertoComunicaçao sobre o diagnóstico pré-natal no âmito da citogenética convencional e da citogenómica.
- The use of Whole-Genome Sequencing to predict antibiotic resistance: practical casesPublication . Manageiro, Vera; Caniça, ManuelaAntibiotic resistance is an emerging problem, becoming a serious threat to global public health. The causes of its spread are complex, as are the strategies to combat this threat. Following recent improvements in sequencing technologies, whole-genome sequencing (WGS) provides a comprehensive alternative in the evaluation and detection of antibiotic resistance mechanisms. In the scope of the analysis of nonsusceptibility of Gram-negative isolates recovered from human, veterinary and environment samples, we identified the presence of a high diversity of resistance mechanisms. To understand the genetic background of those resistance mechanisms, which included oxyimino-β-lactam, fluoroquinolone and colistin resistance-encoding genes, we performed whole genome and plasmid sequencing using a 454 (Roche) and/or MiSeq (Illumina) sequencing strategy. A set of bioinformatic web tools were used to estimate the presence of pathogenicity determinants, antibiotic resistance (AR) genes, and clinically relevant mobile genetic elements. Indeed, the efficient gene capture and spread of resistance determinants by mobile genetic elements are factors to be taken into account, due to their contribution for the co-selection of multidrug resistant strains in the different settings and environment. Furthermore, WGS might be used with great benefit in combination with phenotypic methods for surveillance purposes.
- Borreliose de Lyme em idade PediátricaPublication . Borges, M.; Gouveia, C.; Vieira, J.P.; Lopes de Carvalho, I.; Brito, M.J.Introdução e objetivos: A doença de Lyme é uma entidade rara na idade pediátrica, causada por espiroquetas do complexo Borrelia burgdorferi sensu lato. Pode afetar vários orgãos como pele,sistema nervoso, articulações e coração. Objetivo: Caracterizar a infeção por Borrelia num hospital pediátrico terciário.
- Antifungal ResistancesPublication . Sabino, RaquelThe increasing number of invasive procedures and clinical therapies has led to an increase number of patients at-risk of suffering invasive fungal infections. The prophylaxis with antifungals is now broader used in specic groups of patients. Therefore, it is not surprising the emergence of antifungal resistance. In the follow- ing chapter this issue will be discussed, raising awareness to possible sources as well as modes of transmission of resistant isolates in specic environmental settings.
- Bacterial resistancesPublication . Manageiro, Vera; Salgueiro, Vanessa; Ferreira, Eugénia; Caniça, ManuelaHere we review several factors involved in the emergence of antibiotic resistance. They are numerous, and the constant adaptation of microorganisms to the selective pressure exerted by antibiotics is extraordinary. The monitoring systems to assess antibiotic resistance levels and the extent of dissemination were highlighted. In addition, the success of spread of certain bacterial lineages and resistant mechanisms remains sometimes difficult to determine. The need to enlarge research in the area of antibiotic resistance was also stated, not only to better understand the dynamics of dissemination of resistance between different bacteria and different ecosystems, but also to enlarge the pharmaceutical pipeline of antibacterials against multidrug-resistant pathogens. It is manifest the severe consequences of antibiotic resistances to humans, animals and environment, constituting a global public health priority. In consequence, it should be tackled on all fronts in view to the essential concept of “One World-One Medicine-One Health”.
- Manual Fotográfico de Quantificação de Alimentos IAN-AF 2015-2016Publication . Torres, Duarte; Faria, Nuno; Sousa, Nataline; Teixeira, Sérgio; Soares, Rita; Amorim, Hélder; Guiomar, Sofia; Lobato, Liliane; Oliveira, Catarina; Correia, Daniela; Carvalho, Catarina; Vilela, Sofia; Severo, Milton; Lopes, CarlaO manual de fotográfico de quantificação de alimentos (MQA) foi desenvolvido para apoiar os participantes no Inquérito Alimentar Nacional e de Atividade Física (IAN-AF) a estimar a quantidade consumida de alimentos ou receitas. Os alimentos, as receitas e as porções selecionadas representam, com completude, o consumo alimentar em Portugal, de acordo com dados de estudos prévios, nomeadamente, o estudo EpiPorto (coorte de base-populacional de adultos do Porto), o estudo EpiTeen (Epidemiological Health Investigation of Teenagers in Porto) e o estudo piloto PANEU (Pilot study in the view of a Pan-European dietary survey - adolescents, adults and elderly). O MQA foi integrado no software eAT24 (Electronic Assessment Tool for 24h recall) desenvolvido para a recolha dos dados de consumo durante os questionários às 24-horas anteriores, ou dos diários alimentares, utilizado no trabalho de campo do IAN-AF.
- Evaluation of cytotoxic and genotoxic effects of Microcystin-LR in Saccharomyces cerevisiaePublication . Barreiros, Sara; Valério, Elisabete; Dias, DeodáliaMicrocystins (MC) are hepatotoxins produced by cyanobacteria. Among the MCs, the microcystin-LR (MC-LR), produced by several cyanobacterial species, especially by the species Microcystis aeruginosa, is the most abundant and also the most well studied cyanotoxin. MCs are cyclic peptides which have high affinity for protein phosphatases Serine/Threonine (PPs), namely PP1 and PP2A, thus acting as their inhibitors, especially of the last one. It is from these interactions that a series of events occur which are responsible for the MCs cytotoxic and genotoxic effects on animal cells. It is also known that MCs induce oxidative stress in cells due to the production of reactive oxygen species (ROS), however a complete characterization of the effects of these toxins has not yet been obtained. This project intends to clarify some of the molecular mechanisms of MC-LR toxicity in animal cells using Saccharomyces cerevisiae as an eukaryotic organism model. To evaluate the cytotoxic effects of MC-LR, a cell viability assay was used to determine the functional capacity of the mitochondria, the MTT assay, after exposing the yeasts to different concentrations of MC-LR for 4 hours. Genotoxic effects were evaluated by gene expression studies for genes Rad27, Apn1, Apn2, Ntg1 and Ntg2 (from the BER DNA repair system) and Cdc55 gene which encodes the PP2A phosphatase protein, using the Real-Time qPCR technique. The reference genes used for expression normalization were Alg9 and Taf10. Furthermore, it was attempted to adapt the single cell gel electrophoresis assay (comet assay), conventionally performed on mammalian cells, to Saccharomyces cerevisiae cells, in order to quantify induced DNA breaks. MTT was optimized and successfully used in S. cerevisiae. Apparently, MC-LR is not cytotoxic for Saccharomyces cerevisiae, although these results should be confirmed with other methods that accessed cell viability. Regarding the Comet assay, the results were not conclusive, possibly due to the difficulty in optimizing the method when applied to yeast cells, particularly in the DNA migration on the electric field. However, the first two steps of the YCA protocol were optimized. Concerning the RTqPCR method it was possible to obtain tendencies in the gene expression levels, when compared with the control situation, thus revealing that MC-LR affects differently both BER pathways. Despite the difficulty of reproducing some methods in yeast cells, it appears that microcystin- LR plays a critical role in the toxicity of eukaryotic cells. This work allowed us to contribute with a little more information to a still relative unknown study field.
- Borrelia wingmen: dispersal and maintenance of Borrelia burgdorferi s.l. by birdsPublication . Norte, A. C.; Ramos, J.A.; Araújo, P.M.; da Silva, L.P.; Heylen, D.; Costantini, D.; Eens, M.; Núncio, M.S.; Lopes de Carvalho, I.Lyme borreliosis, caused by Borrelia burgdorferi s.l., is the most prevalent vector-borne disease of moderate climates of the northern hemisfere. In Portugal, several Borrelia genospecies are present in questing ticks, which have different associations with vertebrate reservoir hosts and Lyme borreliosis etiology. To better understand disease risk it is necessary to evaluate the relationships among Borrelia genospecies, their tick vectors and vertebrate reservoir hosts.
- Exposure to Microbiological Agents in Indoor and Occupational EnvironmentsPublication . Viegas, Carla; Viegas, Susana; Gomes, Anita Quintal; Täubel, Martin; Sabino, RaquelThis book intends to provide information about detection and health effects due to bacteria, fungi and viruses in indoor and occupational environments. The book will cover also information about preventive and protective measures to avoid health-hazardous. Case studies will be also addressed to enrich the book with the expertise of each invited author. In addition this book also aims at filling the actual gap regarding information about all the microbiologic agents, since most of the books are dedicated to only one type of microorganisms. For various different biologic agents and metabolites this book will compile information about indoor and occupational presence, detection methods, exposure assessment and health effects. Several settings problems regarding microbiologic agent exposure will be presented through case studies, and also the implementation of preventive and protective measures to avoid/minimize exposure. Importantly, the book will focus on occupational health and/or public health point of view.
- Practical Guidelines for Studies on Sandfly-Borne Phleboviruses: Part I: Important Points to Consider Ante Field WorkPublication . Ayhan, Nazli; Baklouti, Amal; Prudhomme, Jorian; Walder, Gernot; Amaro, Fatima; Alten, Bulent; Moutailler, Sara; Ergunay, Koray; Charrel, Remi N; Huemer, HartwigThe purpose of this review is to provide practical information to help researchers intending to perform "from field to laboratory" studies on phleboviruses transmitted by sandflies. This guideline addresses the different steps to be considered starting from the field collection of sandflies to the laboratory techniques aiming at the detection, isolation, and characterization of sandfly-borne phleboviruses. In this guideline article, we address the impact of various types of data for an optimal organization of the field work intending to collect wildlife sandflies for subsequent virology studies. Analysis of different data sets should result in the geographic positioning of the trapping stations. The overall planning, the equipment and tools needed, the manpower to be deployed, and the logistics to be anticipated and set up should be organized according to the objectives of the field study for optimal efficiency.