Loading...
15 results
Search Results
Now showing 1 - 10 of 15
- Meta-análise do contato com animais como rota de transmissão de toxoplasmose esporádicaPublication . Rodrigues, Vânia; Cadavez, Vasco; Kooh, Pauline; Sanaa, Moez; Gonzales-Barron, Ursula; Rodrigues, VâniaA toxoplasmose é uma infeção causada pelo parasita Toxoplasma gondii, cuja transmissão ocorre por ingestão de alimentos contaminados, contato com animais (zoonose) e de mãe para filho (congénita). O objetivo deste estudo foi sintetizar a associação entre a infeção esporádica por T. gondii e o contato com animais, através da combinação dos resultados de estudos de caso-controlo relevantes, usando a meta-análise para produzir uma estimativa mais precisa da associação global entre o fator de risco e a doença.
- Meta-análise do contato com animais e do consumo de carne como fontes de salmonelose esporádicaPublication . Gonçalves-Tenório, Andiara; Cadavez, Vasco; Rodrigues, Vânia; Kooh, Pauline; Sanaa, Moez; Gonzales-Barron, Ursula; Rodrigues, VâniaAs doenças gastrointestinais representam um importante problema de saúde pública em todo mundo, desta forma a identificação da origem de transmissão é de grande importância para a avaliação e atribuição de risco. Os estudos epidemiológicos de casocontrolo são usados para identificar os fatores de risco associados à transmissão das doenças. A salmonelose, doença causada por vários serotipos de Salmonella spp., pode ser transmitida ao homem de diversas formas. De uma forma geral, os casos esporádicos de salmonelose não partilham o mesmo fator de risco ou rota de contaminação, de modo que os estudos que medem a relação de probabilidades (“odds ratio”, OR) de qualquer fonte de transmissão podem ocultar os riscos reais tornando-os mais difíceis de detetar (Fullerton et al., 2012). Por exemplo, o frango assado é uma importante fonte de contaminação por Salmonella spp., todavia a maioria das porções de frango não estão contaminadas, de modo que a probabilidade de uma pessoa adquirir salmonelose pelo consumo de frango assado é apenas um pouco superior à das pessoas que não consomem frango assado (controlo).
- Hierarquização dos factores de risco associados à salmonelose por meta-análise de estudos caso-controloPublication . Rodrigues, Vânia; Cadavez, Vasco; Gonzales-Barron, Ursula; Kooh, Pauline; Sanaa, Moez; Rodrigues, VâniaOs estudos caso-controlo são uma metodologia de investigação em epidemiologia que permitem analisar, de forma retrospectiva, a exposição a factores de risco das doenças entéricas. O objectivo deste trabalho foi sintetizar a associação entre as infecções esporádicas por Salmonella spp. e os factores de risco, através da combinação dos resultados de estudos casocontrolo. Para uniformizar as categorias de exposição, desenvolvemos uma classificação dos eventuais factores de risco, com as seguintes categorias: viagem, especificidades do hospedeiro, transmissão de pessoa a pessoa, contacto com animais, contaminação pelo ambiente e consumo de alimentos. A pesquisa da literatura relevante foi realizada através dos portais da Science Direct, Pubmed, Scielo, 151 Web of Science e Scopus. Em cada estudo caso-controlo, foi recolhida a medida de associação oddsratio (ORs) da doença com a exposição. Os estudos seleccionados foram classificados quanto ao seu potencial de enviesamento, resultante de deficiências do desenho experimental, da selecção da população e dos métodos utilizados na análise dos dados. Foram também extraídas outras características consideradas importantes, tais como: a população, o desenho experimental, a análise estatística dos dados e o(s) factor(es) de risco. Posteriormente, os ORs globais, para cada factor de risco e das rotas de transmissão, foram estimados por modelos de meta-análise com o software R, e hierarquizados.
- Microbiological safety of goat milk and cheese: evidences from a meta-analysisPublication . Cadavez, Vasco; Rodrigues, Vânia; Gonzales-Barron, Ursula; Rodrigues, VâniaThis chapter synthesizes published information concerning the incidence of zoonotic pathogenic microorganisms – Listeria monocytogenes, Staphylococcus aureus and shigatoxin-producing Escherichia coli – in raw goat milk and cheese. Meta-analytical data were extracted from primary studies undertaken in Brazil, China, Czech Republic, Germany, Iran, Italy, Malaysia, Mexico, Norway, Portugal, Spain, Sweden, Switzerland, Turkey and USA. In both raw goat milk (overall incidence 42.6%; 95% CI: 23.0-64.8%) and cheese (overall incidence 26.4%; 95% CI: 10.8-51.6%), S. aureus was found to be the most frequent contaminant bacterium, which suggests that control measures during milk handling are still to be reinforced. In addition, the high frequency of detection of generic E. coli in raw goat milk cheese (overall incidence 11.9%; 95% CI: 3.8- 31.6%) is another indicator of hygiene deficiencies during production. Moreover, E. coli strains with virulence genes have been very frequently detected in raw goat milk (overall incidence 10.5%; 95% CI: 5.3–19.6%). L. monocytogenes, a pathogen that mainly affects the susceptible population, presented a high incidence in both raw goat milk (overall incidence 3.4%; 95% CI: 2.2-5.1%) and goat milk cheese (overall incidence 8.5%; 95% CI: 4.9-14.6%). In conclusion, the present meta-analysis confirms that raw goat milk and cheese are important vehicles of transmission of food-borne diseases. Further research work towards improving the current microbiological quality of these products, particularly in traditional production units, is essential.
- Development of a loop-mediated isothermal amplification assay for the rapid detection of Styphnolobium japonicum (L.) Schott as an adulterant of Ginkgo biloba (L.)Publication . Rodrigues, Vânia; Honrado, Mónica; Santos, Joana; Pinto, M. Alice; Amaral, Joana S.; Rodrigues, VâniaSpecies adulteration is a concern in herbal products, especially when plant substitutes of lower economic value replace valuable botanicals. Styphnolobium japonicum is well known as a potential adulterant of Ginkgo biloba, which is one of the most demanded medicinal plants due to its wide use in pharmaceuticals, food supplements, and traditional medicine. Despite bearing some resemblance to ginkgo's flavonol composition, S. japonicum lacks many of G. biloba's desired therapeutic properties. To prevent adulteration practices, it is crucial to implement rigorous quality control measures, including fast and simple diagnostic tools that can be used on-field. Purpose: This study aims to develop for the first time a species-specific loop-mediated isothermal amplification (LAMP) method for the fast identification of S. japonicum in ginkgo-containing products. Methods: A set of four specific primers (SjF3, SjB3, SjFIP, and SjBIP) and loop primers (SjLF and SjLB) were designed for a LAMP based assay using the 5.8S partial sequence and the internal transcribed spacer 2 of nuclear ribosomal DNA of S. japonicum. Results: The successful amplification of the LAMP assay was inspected through visual detection, with the highest intensity recorded at the optimal conditions set at 68 °C for 40 min. The primers showed high specificity and were able to accurately discriminate S. japonicum from G. biloba and 49 other species of medicinal plants. Furthermore, the proposed LAMP assay proved to be fast, selective, and highly sensitive, as demonstrated by the absolute and relative limits of detection, which were reached at 0.5 pg for S. japonicum DNA and 0.01 % S. japonicum in G. biloba, respectively. Conclusions: This novel approach allows easy identification and discrimination of S. japonicum as a potential adulterant of G. biloba, thus being a useful tool for quality control. Compared to chromatographic or PCR-based methods, the assay proved to be fast, sensitive and did not require expensive equipment, thus offering the possibly usage in field analysis.
- Meta-learning approach for bacteria classification and identification of informative genes of the Bacillus megaterium: tomato roots tissue interactionPublication . Rodrigues, Vânia; Deusdado, Sérgio; Rodrigues, VâniaPlant growth-promoting rhizobacteria (PGPRs) are bacteria that colonize the plant roots. These beneficial bacteria have an influence on plant development through multiple mechanisms, such as nutrient availability, alleviating biotic and abiotic stress, and secrete phytohormones. Therefore, their inoculation constitutes a powerful tool towards sustainable agriculture and crop production. To understand plant-PGPRs interaction we present the classification of PGPR using machine learning and meta-learning classifiers namely Support Vector Machine (SVM), Kernel Logistic Regression (KLR), meta-SVM and meta-KLR to predict the presence of Bacillus megaterium inoculated in tomato root tissues using publicly available transcriptomic data. The original dataset presents 36 significantly differentially expressed genes. As the meta-KLR achieved near-optimal performance considering all the relevant metrics, this meta learner was afterwards used to identify the informative genes (IGs). The outcomes showed 157 IGs, being present all significantly differentially expressed genes previously identified. Among the IGs, 113 were identified as tomato genes, 5 as Bacillus subtilis proteins, 1 as Escherichia coli protein and 6 were unidentified. Then, a functional enrichment analysis of the tomato IGs showed 175 biological processes, 22 molecular functions and 20 KEGG pathways involved in B. megaterium–tomato interaction. Furthermore, the biological networks study of their Arabidopsis thaliana orthologous genes identified the co-expression, predicted interaction, shared protein domains and co-localization networks.
- Metalearning approach for leukemia informative genes prioritizationPublication . Rodrigues, Vânia; Deusdado, Sérgio; Rodrigues, VâniaThe discovery of diagnostic or prognostic biomarkers is fundamental to optimize therapeutics for patients. By enhancing the interpretability of the prediction model, this work is aimed to optimize Leukemia diagnosis while retaining a high-performance evaluation in the identification of informative genes. For this purpose, we used an optimal parameterization of Kernel Logistic Regression method on Leukemia microarray gene expression data classification, applying metalearners to select attributes, reducing the data dimensionality before passing it to the classifier. Pearson correlation and chi-squared statistic were the attribute evaluators applied on metalearners, having information gain as single-attribute evaluator. The implemented models relied on 10-fold cross-validation. The metalearners approach identified 12 common genes, with highest average merit of 0.999. The practical work was developed using the public datamining software WEKA.
- Meta-análise do contato com animais e do consumo de carne como fontes de salmonelose esporádicaPublication . Gonçalves-Tenório, Andiara; Cadavez, Vasco; Rodrigues, Vânia; Kooh, Pauline; Sanaa, Moez; Gonzales-Barron, Ursula; Rodrigues, VâniaAs doenças gastrointestinais representam um importante problema de saúde pública em todo mundo, desta forma a identificação da origem de transmissão é de grande importância para a avaliação e atribuição de risco. Os estudos epidemiológicos de casocontrolo são usados para identificar os fatores de risco associados à transmissão das doenças. A salmonelose, doença causada por vários serotipos de Salmonella spp., pode ser transmitida ao homem de diversas formas. De uma forma geral, os casos esporádicos de salmonelose não partilham o mesmo fator de risco ou rota de contaminação, de modo que os estudos que medem a relação de probabilidades (“odds ratio”, OR) de qualquer fonte de transmissão podem ocultar os riscos reais tornando-os mais difíceis de detetar (Fullerton et al., 2012). Por exemplo, o frango assado é uma importante fonte de contaminação por Salmonella spp., todavia a maioria das porções de frango não estão contaminadas, de modo que a probabilidade de uma pessoa adquirir salmonelose pelo consumo de frango assado é apenas um pouco superior à das pessoas que não consomem frango assado (controlo).
- Food source atribution of human campylobacteriosis by meta-analysis of case-control studiesPublication . Rodrigues, Vânia; Cadavez, Vasco; Kooh, Pauline; Moez, Sanna; Gonzales-Barron, Ursula; Rodrigues, VâniaA case-control study is a powerful approach among epidemiologists to investigate the causal effect of exposure and enteric illness. To combine the associations between sporadic campylobacteriosis and the different food pathways of exposure, the results from relevant case-control studies were extracted and their odds-ratio (OR) measures were meta-analysed within food category partitions by population type, extracting the variability due to both primary studies and model types. In the mixed population, the most important determinants of disease turned out to be: consumption of raw milk (pooted OR=2. 64), poultry (OR=1. 78), raw milk's cheese (OR=1. 72), BBQ meats (OR=1. 67), fast-food composite (OR=1. 59) and raw seafood (OR=1. 50). On the other hand, consumption of raw-egg containing products (OR=4. 85), raw milk (OR=3. 05), pork (OR=2. 34), minced beef (OR=2.27), processed meats (OR=2.18), any composite food eaten out (OR=2.16) and poultry meat (OR=2.08) were found to bear the highest risk of campylobacteriosis in the children population.
- Pathogens-in-foods: a database of occurrence of microbial hazerds in foods commercialised in EuropePublication . Deusdado, Sérgio; Cadavez, Vasco; Rodrigues, Vânia; Kooh, Pauline; Moez, Sanna; Gonzales-Barron, Ursula; Rodrigues, VâniaThe objective of this study was to build a database of the occurrence (both prevalence and counts) of the most important biological hazards in foods commercialised in Europe. For this, systematic literature searches were first conducted for every pathogen; namely, Salmonella, Campylobacter, Shigatoxin-producing Escherichia co//, Listería monocytogenes, Yersinia enterocolitica, Bacillus cereus, Clostridium perfringens, Staphylococcus aureus, Toxoplasma gondií, norovirus, Hepatitis A vírus, Hepatitis E virus, Cryptosporidium ana Giardia duodenalis; and after screening for relevance and methodological quality assessment, data were carefully extracted from the primary studies into a harmonised arrangement consisting of primary study characteristics, food characteristics ana stage within the food chain, microbiological methods, prevalence results, enumeration results and potential for bias. Based on the microbiological survey results extracted from 977 primary studies, the database Pathogens-ln-Foods hás been constructed to facilitate data access and retrieval according to hazard, food class, country or any other relevant variable, with the ability to execute simple statistical calculations.