Percorrer por autor "Fernandes, Camila"
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- Epigenomics as a novel approach to explore the toxic effects of nanomaterialsPublication . Ventura, Célia; Vieira, Luís; Valente, Ana; Fernandes, Camila; Silva, Catarina; Louro, Henriqueta; Ferreira, Paulo J.T.; Silva, Maria JoãoIn recent years, there has been a huge development of innovative engineered nanomaterials with potential use in industrial and biomedical applications. This increased widespread use raised concerns that nanomaterials may elicit human adverse health effects through occupational, environmental or consumer exposure. Many toxicity studies, mainly in vitro, have showed that some nanomaterials, such as carbon nanotubes or titanium dioxide nanoparticles (TiO 2 NP), may cause genotoxicity, inflammation, and associated adverse health effects. Nevertheless, few studies have focused on the nanomaterials effect s on the epigenome, namely, modifications of histone tails, microRNA expression or DNA methylation. Here we wil l present two “omics” studies based on next generation sequencing , one focusing on the effect of three nanocellulose s derived from Eucaliptus globulus kraft pulp on the microRNA expression of BEAS 2B, and an other one focusing on the effect of three types of TiO 2 NP on the DNA methylation of Caco 2 cells. Regarding the former 24h exposure to fibrillar micro/nanocellulose s did not induced significant (FDR ≤ 0.05) differentially expressed microRNAs, as compared to non exposed cells. By contrast, the crystalline nanocelul l ose induced the over and under expression of 22 and 30 microRNAs, respectively. These microRNAs can be f urther explored as potential biomarkers for human biomonitoring and co ntribute to elucidate the mechanisms of action of crystalline nanocellulose. As to the genome wide methylation study Reduced Representative Bisulfite Sequencing allowed the identification of significant ( p ≤ 0.05) differential methylation of 92, 70, and 88 gene sequences for the anatase, rutile and brookite phase TiO 2 NP exposures, respectively. Functional pathway analysis of these methylation changes showed that all TiO 2 NP may affect cell proliferation, differentiation, and survival, and suggested different molecular mechanisms of action for each type of TiO 2 NP. In conclusion, epigenomics revealed to be a powerful tool to understand the key molecular events underlying nanomaterials effects.
- Preliminary characterization of Vibrio cholerae strains isolated from seafood samples marketed in PortugalPublication . Lopes, Teresa; Lopes, David; Moura, Isabel Bastos; Sousa, Isabel; Rodrigues, João; Fernandes, Camila; Barreira, Maria João; Maia, Carla; Correia, Cristina Belo; Pintado, Cristina; Saraiva, Margarida; Batista, Rita; ElsevierVibrio cholerae, a natural inhabitant of aquatic ecosystems, has been related with gastrointestinal infections, particularly those associated with seafood consumption. This preliminary study aimed to evaluate the presence and characteristics of Vibrio cholerae, in seafood marketed in Portugal, given its potential role as a foodborne pathogen. Thus, the occurrence of Vibrio cholerae in 129 seafood raw samples (105 of shrimp and 24 of oysters), marketed in Portugal, was assessed. Isolates’ characterization regarding the presence of antimicrobial resistance (AMR) genes and of pathogenicity-specific genetic traits was attained by whole-genome sequencing (WGS). Core-genome Multi Locus Sequence Typing (cgMLST) analyses to evaluate the genetic relatedness among the isolates, and with other V. cholerae strains isolated in the world, as well as phenotypic AMR (performed by disc diffusion), were also attained. Overall, 43/129 (33.3 %) of the samples tested positive for V. cholerae (41/105 (39.1 %) of the shrimp and 2/24 (8.3 %) of the oysters’ samples). WGS analyses classified the studied strains as non-O1/non-O139 Vibrio cholerae (NOVC), lacking the main cholerae virulence factors encoded by the CTX phage. However, they carry diverse virulence factors similar to those found in O1 and O139 strains and/or in NOVC clinical strains. Furthermore, eight strains were classified as multidrug-resistant (MDR). The cg-MLST analyses revealed six genetic clusters among the 43 isolates (three identified sequence types - ST829, ST833, ST1085). Although it was not possible to find a close genetic relatedness between the studied V. cholerae strains and other deposited in PuBMLST database, a high genetic proximity among some strains isolated in different countries and from different sources (environmental and human) was observed, reinforcing the importance of a One Health approach. Assessing occurrence, pathogenic potential and genetic relatedness of Vibrio cholerae strains in the Portuguese food supply chain, this study contributes to understand their public health significance and supports a One Health approach to prevent foodborne outbreaks, contributing to food safety.