Percorrer por autor "Duarte, A."
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- Antioxidant properties of coriander essential oil and linalool and their potential to control Campylobacter spp.Publication . Duarte, A.; Luís, A.; Oleastro, Mónica; Domingues, F.C.Foodborne diseases remain common around the world with Campylobacteriosis being the most commonly reported zoonosis in the European Union in 2013. Campylobacter jejuni and Campylobacter coli are the main species associated with human illness. Furthermore, Campylobacter can develop biofilms which is becoming a major problem within the food industry. In addition to foodborne pathogens, oxidation is a non-microbial cause of deterioration of food causing loss of quality and safety. Thus, there is an urgent need in the food industry for new and effective strategies that can help prevent food contamination, spoilage and consequently, foodborne illnesses. Essential oils are known for their antimicrobial and antioxidant properties and are already widely used in the food industry. So, the aim of this work was to study the antimicrobial and anti-biofilm activity of coriander essential oil and its major compound linalool against C. jejuni and C. coli strains, as well as their effect in the quorum sensing (QS) system and their potential as antioxidants. Our results, demonstrated that both compounds have anti- Campylobacter activity, inhibited in vitro biofilm formation and promoted biofilm dispersion even at sub-MIC concentrations and interfered with the QS system through the inhibition of violacein production. Moreover, the essential oil and linalool were shown to have radical scavenging properties and lipid peroxidation inhibition ability which could make them potential alternatives to synthetic antioxidants. In sum, our results demonstrated the antibacterial, anti-biofilm, anti-QS and antioxidant potentials of the coriander essential oil and its major compound, linalool, suggesting that they could be used in the food industry to enhance shelf life of food products and increase food safety without requiring chemical additives or preservatives.
- A DNA barcode reference library of Portuguese mosquitoesPublication . Madeira, S.; Duarte, A.; Boinas, F.; Osório, H.C.Mosquitoes are important biological vectors of pathogens and species identification in all life stages is the first step for effective monitoring and control of mosquito-borne diseases. Molecular methods for species identification have been developed over the last years to overcome the limitations of the taxonomic identification based on morphology. DNA barcoding, using a fragment of the mitochondrial cytochrome oxidase I (COI) gene, can be used for species identification but a reliable and comprehensive reference database of verified sequences is required. In this study, we aimed to generate a DNA barcode reference library for the identification of mosquito species from Portuguese mosquito fauna, including most relevant vector species. Mosquitoes captured under the National Vector Surveillance Program (REVIVE) were processed for DNA extraction, COI gene fragment amplification and sequencing. Nighty-eight barcode sequences were obtained, representing 26 species and 6 genera. Sequences were submitted to GenBank and BOLD and were used for validation of phenetic classification. Barcode Index Number (BIN) assignment and Automatic Barcode Gap Discovery (ABGD) were used and clustered COI sequences into twenty-five molecular operational taxonomic units (MOTUs). This is the first comprehensive study that combines morphological and molecular identification of most mosquito species present in Portugal aiming to offer a reliable framework for mosquito species identification.
- Guidelines for the Detection of Rickettsia spp.Publication . Portillo, A.; de Sousa, R.; Santibánez, S.; Duarte, A.; Edouard, S.; Fonseca, I.P.; Marques, C.; Novakova, M.; Palomar, A.M.; Santos, M.; Silaghi, C.; Tomassone, L.; Zúquete, S.; Oteo, J.A.The genus Rickettsia (Rickettsiales: Rickettsiaceae) includes Gram-negative, small, obligate intracellular, nonmotile, pleomorphic coccobacilli bacteria transmitted by arthropods. Some of them cause human and probably also animal disease (life threatening in some patients). In these guidelines, we give clinical practice advices (microscopy, serology, molecular tools, and culture) for the microbiological study of these microorganisms in clinical samples. Since in our environment rickettsioses are mainly transmitted by ticks, practical information for the identification of these arthropods and for the study of Rickettsia infections in ticks has also been added.
- Human, food and animal Campylobacter spp. isolated in Portugal: high genetic diversity and antibiotic resistance ratesPublication . Duarte, A.; Santos, A.; Manageiro, V.; Martins, A.; Fraqueza, M.J.; Caniça, Manuela; Domingues, F.; Oleastro, M.Infections by Campylobacter jejuni and Campylobacter coli are considered the major cause of bacterial gastroenteritis in humans, with food being the main source of infection. In this study, a total of 196 Campylobacter strains (125 isolates from humans, 39 from retail food and 32 from food animal sources) isolated in Portugal between 2009 and 2012 were characterised by multilocus sequence typing (MLST) and flaA short variable region (SVR) typing. Susceptibility to six antibiotics as well as the mechanisms underlying antibiotic resistance phenotypes was also studied. Based on MLST typing, C. coli strains were genetically more conserved, with a predominant clonal complex (CC828), than C. jejuni strains. In contrast, C. coli isolates were genetically more variable than C. jejuni with regard to flaA-SVR typing. A high rate of resistance was observed for quinolones (100% to nalidixic acid, >90% to ciprofloxacin) and, in general, resistance was more common among C. coli, especially for erythromycin (40.2% vs. 6.7%). In addition, most isolates (86%) were resistant to multiple antimicrobial families. Besides the expected point mutations associated with antibiotic resistance, detected polymorphisms in the cmeABC locus likely play a role in the multiresistant phenotype. This study provides for the first time an overview of the genetic diversity of Campylobacter strains from Portugal. It also shows a worrying antibiotic multiresistance rate and the emergence of Campylobacter strains resistant to antibiotics of human use.
- Human, food and animal Campylobacter spp. isolated in Portugal: high genetic diversity and antibiotic resistance ratesPublication . Duarte, A.; Santos, A.; Manageiro, V.; Martins, A.; Fraqueza, M.J.; Caniça, Manuela; Domingues, F.C.; Oleastro, M.Infections by Campylobacter jejuni and Campylobacter coli are considered the major cause of bacterial gastroenteritis in humans, with food being the main source of infection. In this study, a total of 196 Campylobacter strains (125 isolates from humans, 39 from retail food and 32 from food animal sources) isolated in Portugal between 2009 and 2012 were characterised by multilocus sequence typing (MLST) and flaA short variable region (SVR) typing. Susceptibility to six antibiotics as well as the mechanisms underlying antibiotic resistance phenotypes was also studied. Based on MLST typing, C. coli strains were genetically more conserved, with a predominant clonal complex (CC828), than C. jejuni strains. In contrast, C. coli isolates were genetically more variable than C. jejuni with regard to flaA-SVR typing. A high rate of resistance was observed for quinolones (100% to nalidixic acid, >90% to ciprofloxacin) and, in general, resistance was more common among C. coli, especially for erythromycin (40.2% vs. 6.7%). In addition, most isolates (86%) were resistant to multiple antimicrobial families. Besides the expected point mutations associated with antibiotic resistance, detected polymorphisms in the cmeABC locus likely play a role in the multiresistant phenotype. This study provides for the first time an overview of the genetic diversity of Campylobacter strains from Portugal. It also shows a worrying antibiotic multiresistance rate and the emergence of Campylobacter strains resistant to antibiotics of human use.
- A infeção humana por Campylobacter em Portugal: alguns dados epidemiológicosPublication . Duarte, A.; Santos, A.; Benoliel, J.; Domingues, F.; Oleastro, M.
- Lack of Cystatin B Protein as a Cause Of Myoclonic EpilepsyPublication . Amaral, O.; Duarte, A.; Pinto, E.; Freitas, J.; Chaves, J.Unverricht-Lundborg disease (ULD; MIM 254800) is the most frequent cause of progressive myoclonic epilepsy. CSTB mutations (locus 21q22.3; MIM 601145), with cystatin B loss of function and subsequent loss of lysosomal association, have been described as the major cause of this disease.
- Overview on canine vector-borne diseases agents transmitted by ticks in PortugalPublication . Da Fonseca, I.P.; Marques, C.; Duarte, A.; Leal, A.; Meireles, J.; Santos-Silva, M.M.; Santos, A.S.
- The disease modelling value of a folklore FAIRYtale: SHEDing light over a special group of genetic disordersPublication . Carvalho, S.; Santos, J.I.; Moreira, L.; Gaspar, P.; Gonçalves, M.; Encarnação, M.; Ribeiro, D.; Duarte, A.; Prata, M.J.; Coutinho, M.F.; Alves, SandraThe problem we are addressing: Despite extensive research, the links between accumulation of glycosaminoglycans (GAGs) and the clinical features seen in patients suffering from various forms of Mucopolysaccharidoses (MPSs) have yet to be further elucidated. These Lysosomal Storage Diseases (LSDs) present symptoms, which may (or may not) include critical musculoskeletal and cardiovascular alterations, respiratory problems, and serious neurological dysfunctions. The skeletal and brain systems are the hardest ones to access and, consequently, those in greatest need of additional knowledge and novel therapeutic solutions.
- The impact of an acute exercise challenge on DNA damage: an human interventionPublication . Duarte, A.; Abreu, A.; Silva, D.; Carvalho, J.; Montanha, T.; Moreira, A.; Teixeira, J. P.; Costa, C.Even though it is commonly accepted that a regular physical activity along with a healthy diet brings positive health-related outcomes, it also seems to be related to several alterations in the human metabolism, organs, cells and deoxyribonucleic acid (DNA). Indeed, there is consistent evidence supporting that above a certain level of intensity and duration, exercise may induce an increase in the generation of reactive oxygen species (ROS). The aim of this study was to analyse the immediate impact of an acute exercise challenge on human’s DNA damage, taking into account their individual characteristics and fitness levels.