DSA - Apresentações orais em encontros internacionais
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- Deciphering a potential toxic synergy between persistent organic pollutantsPublication . Puskar, Ljiljana; Jordão, LuísaPlastic, massively used in everyday life, inevitably accumulates in the environment, becoming a persistent pollutant due to its reduced and/ or extremely slow recyclability1. Plastic particles in the micro and nano range, known as micro (MP) and nanoplastics (NP), respectively represent a huge ecotoxicological challenge. Due to their high surface areas, they might ad/absorb other persistent pollutants with similar chemical properties, such as polycyclic aromatic hydrocarbons (PAHs), with unpredictable effects on persistence and distribution in the environment2. MPs/NPs, with or without pollutants ad/absorbed, could enter the trophic chain at the level of invertebrates, inflicting toxicological effects through all levels of the ecosystem3. Polystyrene MPs and PAHs previously found in water samples (e.g. fluoranthene, phenanthrene)4 and known to be adsorbed by MPs (Pyrene, benzo(a) pyrene)5 will be used in the study. PAH’s mixtures will be used to mimic environmental samples and single compounds will be used in order to understand the individual contribution of each compound for the observed toxic effect. This experimental approach will also allow to evaluate a potential synergy between compounds with effect on toxicity. Since PAHs and MPs have similar chemical properties, they are known to adsorb to each other. We will use PAHs adsorbed to MPs to test higher concentrations of PAHs (not soluble in aqueous solutions such as cell culture medium) and to document the intracellular distribution of adsorbed versus free PAHs. Concerning MPs only one material will be used at this stage. Polystyrene was selected because it is commercially available in spheres suitable for internalization by HepG2 cells and was previously isolated from environmental samples 4. This study could contribute to identify differences in toxicity and contribute to the elucidation of the underlying toxicity mechanisms using molecular biology protocols, light/electron microscopy and FTIR micro/spectrometry.
- Biofilms, Infection and Antimicrobials ResistancePublication . Jordao, LuisaBiofilm-associated infections are a public health concern especially in the context of healthcare-associated infections (HAI). These infections have often as aetiological agents microorganisms resistant to multiple antimicrobials and desinfection agents/ procedures. In this context is urgent to identify the reservoirs potential patogens in the healthcare unit in order to mitigate the impact of HAI. Here we focused on identifying potential pathogens in water, evaluating their susceptibility to antimicrobials and desinfectants on planktonic stage or organized in biofilms. In addition, the role played by biofilm assembly on catheter related bloodstream infections was assessed by a prospective observational study. The aetological agents and their susceptibility to antimicrobials were evaluated. For the most prevalent aetiological agents, staphylococci, whole genome sequecing was performed to confirm the isogenicity of the microorganisms isolated from the central venous catheter and the blood. Since biofilms are multimicrobial communities the biofilm assembly by the aetiological agents of a coinfection bloodstream infection were monitored in vitro.
- Catheter related bloodstream infection caused by E. cloacae and Candida parapsilosis: Are biofilms guilty?Publication . Štefánek, Matúš; Borges, Vítor; Wenner, Sigurd; Nogueira, Isabel D.; Pinto, Miguel; Faria, Isabel; Pessanha, Maria Ana; Veríssimo, Cristina; Sabino, Raquel; Rodrigues, João; Matias, Rui; Carvalho, Patrícia Almeida; Gomes, João Paulo; Bujdáková, Helena; Jordao, LuisaBiofilm-associated infections is a public health concern in the context of healthcare associated infections (HAI) such as catheter related bloodstream infections (CRBSI). Here the dynamics of two top ten etiological agents of CRBSI, Enterobacter cloacae and Candida parapsilosis isolated from a CRBSI’s patient, were studied to get insights on the role played by biofilms on this HAI. Antimicrobial susceptibility of CVC and HC’s isolates was evaluated according to EUCAST guidelines. Single and/or mixed biofilms assembled on different materials in Mueller-Hinton broth with 2% glucose were assessed by crystal violet assay and scanning electron microscopy (SEM). Fluorescence in situ hybridization (FISH) was used for identification purposes and to assess microorganisms distribution within the biofilm (3D reconstruction) complemented with Focus Ion Beam (FIB)-SEM to assess biofilms assembled on the inner/outer CVC’s surfaces (tomograms). Whole-genome sequencing (WGS) was performed for all isolates. All isolates were antimicrobial resistant. Of note E.cloacae resistance to collistin and an additional resistance of the CVC compared to HC-isolate (ceftolozame-tazobactam) probably linked to a mutation in rpoB gene. Candida resistance to fluconazol might be explained by ERG11 gene mutation. Enterobacter and Candida assembled biofilms on glass, polystyrene and polyurethane being mixed biofilms denser when both microorganism were present from the beginning. FISH and SEM analysis showed that biofilm bottom layer was in all cases richer in E.cloacae. Using environmental isolates of the same species we showed that this biofilm phenotype is not a general feature. Using polyurethane catheters (shape/material factor), denser mixed biofilms richer in EPS were observed. A distinct phenotype was present on the patient’s CVC by SEM and FIB/SEM. WGS confirmed the genetic identity of the pair CVC/HC isolates, while corroborating the virulence potential and observed antimicrobial resistant character of the studied CRBSI-driving pathogens. The results suggest that biofilms allow interaction and adaptation of microorganisms belonging to different kingdoms (Bacteria and Fungi). Adaptation might affect virulence in a transitory or permanent fashion, with potential impact on microorganisms’ potential to cause CRBSI.
- Indoor levels and health risk assessment of volatile organic compounds in Portuguese homesPublication . Slezakova, K.; Costa, C.; Valongo, C.; Teixeira, J.P.; Madureira, J.About indoor levels and health risk assessment of volatile organic compounds in Portuguese homes.
- Biocompatibility evaluation of CeO2 nanoparticles to be employed as nanodrugs in brain cancer nanomedicinePublication . Fernández-Bertólez, Natália; Touzani, Assia; Martínez, L.; Reis, Ana Teresa; Fraga, Sónia; Teixeira, João Paulo; Costa, Carla; Pásaro, Eduardo; Laffon, Blanca; Valdiglesias, VanessaCerium dioxide nanoparticles (CeO2NP) have recently gained attention for their unique structure-dependent properties, antioxidant enzyme-like behaviour, ROS scavenging activity and great potential for biomedical applications. In addition to their antioxidant and anti-inflammatory activity, CeO2NP are also known to exhibit anticancer potential, providing an attractive opportunity for use in cancer therapy, as a pharmacological agent and/or in drug/gene delivery systems [1]. Therefore, the main objective of this STSM was to evaluate the cytotoxic and genotoxic effects on human glioblastoma A172 cells exposed for 3, 24 and 48h to CeO2NP (1- 100µg/ml), to verify their safety to be used as possible nanomedicines for brain cancer treatment, specifically glioblastoma [2]. In addition, cell-specific differences in nanoceria effect were evaluated by comparing the results obtained with those observed in human neuronal SH-SY5Y cells exposed under the same experimental conditions. After carrying out the physicochemical characterization and analysing the cellular uptake of the CeO2NP, potential alterations in cell viability (MTT assay) and induction of DNA double-strand breaks (γH2AX assay) caused by the exposure were determined. The possible NP interference with assay methodologies was previously addressed and eliminated when necessary. Results obtained showed that, although there was a significant dose- and time-dependent internalization of NP by both cell types, nanoceria induced scarce cytotoxicity or genotoxicity in both cell lines, being restricted to the highest doses and longer exposure time tested. In general, data obtained suggest a high biocompatibility of CeO2NP under the tested conditions, except for glioblastoma cells exposed for 48h from 25 to 100µg/ml. These results provide a better understanding of the CeO2NP interaction with nervous system cells and their possible adverse effects. However, further studies are necessary to delve into the differential behaviour of these NP depending on the nervous cell type tested.
- Effect biomarkers in e-waste management workersPublication . Silva, Maria João; Aimonen, K.; Louro, Henriqueta; Tavares, A.; Moreira, R.; Catalan, J.; Duca, R.C.; Godderis, L.; Mahiout, S.; Martins, C.; Martinsone, I.; Matisane, L.; Namorado, S.; Van Nieuwenhuyse, A.; Pinhal, H.; Porras, S.; Remes, J.; Scheepers, P.; Verdonck, J.; Viegas, S.; Santonen, T.; HBM4EU E-waste study teamDuring e-waste handling/processing, a broad range of toxic chemicals (metals and persistent organic compounds), are released and may affect workers’ health. This work intended to identify genotoxic effects in workers from European e-waste management companies. Micronuclei were analysed in peripheral blood lymphocytes (MNPBL) from 95 workers and 50 controls and in reticulocytes (MNRET) from 82 workers and 41 controls. No statistically significant differences were detected between the total exposed and control groups, for both MNPBL and MNRET frequencies. Stratification of workers in subgroups according to the main activities performed revealed that the subgroup involved in batteries recycling (n=23) presented a frequency of MNPBL significantly higher than that of controls. Significant differences in MNPBL frequencies were also found between battery workers and the subgroups handling/processing white goods, metals and plastics, and miscellaneous E-waste; no differences in MNRET frequencies among subgroups were detected. Worth to note, the subgroup dealing with brown goods (n=12) displayed the highest MNPBL and MNRET frequencies, although statistical significances were not observed when comparing with the other subgroups or controls. These preliminary results highlight the value of adding effect biomarkers to biomonitoring campaigns, to uncover groups of workers at enhanced risk and to prioritize risk management measures’ implementation.
- Unlocking the Potential of Environmental and Health Research with FAIREHRPublication . Zare Jeddi, Maryam; Hopf, N.; Louro, Henriqueta; Silva, Maria João; Costa, Carla; Viegas, S.; Scheepers, P.; Cubadda, F.; Ghosh, M.; Ali, I.; Santonen, T.; von Goetz, N.; Bessems, J.; Galea, K.S.Current challenges in data comparability, integration, and management, hinder effective utilization of the large amount of data generated in environment and health studies. The European chapter of the International Society of Exposure Science (ISES Europe) Human Biomonitoring (HBM) Working Group is developing a global preregistration platform “FAIR Environment and Health Registry (FAIREHR)” to address these challenges. The focus is initially on the HBM domain, towards the implementation of FAIR (findable, accessible, interoperable, reusable) principles throughout the data lifecycle. Preregistration of HBM studies in a peer review-based registry like FAIREHR would stimulate communication and interaction among HBM communities leading to improved HBM study designs as well as generating comparable results worldwide. Using common standards and ontologies will make data better interoperable and functional for machine discovery. FAIREHR will also provide information on data licenses and request procedures necessary to access datasets of interest. Overall, the FAIREHR platform gathers many stakeholders (scientists, regulators, policy makers, life science companies, publishers, and funding bodies) interested in tracking and identifying planned, ongoing, and completed studies. FAIREHR is expected to benefit research, innovation and environment and public health policies by providing FAIR data that can be readily utilized for protecting human health.
- Neuron and Glial Cells Exposed to Cerium Dioxide Nanoparticles: Results from MTT and γH2AX AssaysPublication . Fernández-Bertólez, Natalia; Touzani, Assia; Martínez, Luisa; Méndez, Josefina; Reis, Ana Teresa; Costa, Carla; Fraga, Sonia; Teixeira, João Paulo; Pásaro, Eduardo; Laffon, Blanca; Valdiglesias, VanessaCerium dioxide nanoparticles (CeO2NP) show antioxidant enzyme-like properties and reactive oxygen species (ROS) scavenging activity, making them a promising material for potential therapeutic applications in neurodegenerative diseases. The objective of this work was to assess the biological behavior of CeO2NP in human SH-SY5Y neuronal and A172 glial cells by means of the MTT assay and the γH2AX assay. Despite the significant dose- and time-dependent NP internalization by both cell lines, nanoceria generally presented scarce cytotoxicity or genotoxicity, essentially restricted to the highest NP doses and longest exposure times. In conclusion, a high biocompatibility of CeO2NP was observed under the conditions tested.
- Genotoxicity in peripheral blood leukocytes and reticulocytes of e-waste management workersPublication . Aimonen, K.; Silva, Maria João; Tavares, Ana; Moreira, Rodrigo; Louro, Henriqueta; Catalán, J.; Duca, R.; Godderis, L.; Mahiout, S.; Martins, C.; Martinsone, I.; Matisane, L.; Namorado, S.; Van Nieuwenhuyse, A.; Pinhal, Hermínia; Porras, S.; Remes, J.; Verdonck, J.; Viegas, S.; Scheepers, P.; Santonen, T.The European Commission has recently adopted a new Circular Economy Action Plan, which recognizes the critical role of material circulation in achieving sustainable development. The waste management sector will play a pivotal role in this, and an increase in the number of workers involved in waste recycling is expected. However, a recent multi-centric study conducted as part of the European Human Biomonitoring Initiative (HBM4EU) highlights potential occupational health risks associated with e-waste management. This study reports the exposure of e-waste workers from six European countries to metals and the early genotoxic effects from exposure to a wide array of toxic chemicals (and their mixtures) in the occupational environment. The results showed that e-waste workers are exposed to higher levels of hazardous metals such as lead (Pb), cadmium (Cd), mercury (Hg), and chromium (Cr) than controls. Significantly higher levels were detected in the post-shift urine and blood samples of different subcategories of e-waste workers. Especially the level of Pb was elevated in urine and blood samples among all worker categories, and the highest values were detected in battery recycling workers. Genotoxic effects were assessed by the micronucleus frequencies in peripheral blood lymphocytes (MNPBL) and reticulocytes (MNRET). MNPBL were analyzed in 95 workers and 50 controls, and MNRET in 82 workers and 41 controls. While there were no statistically significant differences between all workers and controls, the subgroup of battery recycling workers showed significantly higher frequency of MNPBL than controls or other exposed subgroups such as workers handling white goods, metals and plastics or miscellaneous e-waste. The highest MNPBL and MNRET frequencies were observed in workers handling brown goods, but the difference to controls, or to the other worker categories, was not statistically significant. Post-shift urinary levels of studied metals did not show positive correlation with the micronucleus frequencies, which might be partially explained by the heterogeneity of activities considered and related exposure levels found. In addition to metals, the study also measured exposure to flame retardants, phthalates, and polychlorinated biphenyls (PCBs) and, thereby, correlations between exposure to those compounds and effect biomarkers will be further explored. Overall, the study highlights the need to raise awareness of potential hazards and improve risk management measures in the e-waste management sector. The micronucleus results provide valuable new information on early biological effects from occupational exposures during e-waste management that also contribute to identifying worker groups that are at higher risk of adverse health effects.
- Tackling the increasing threat of Smoke Health Impacts from Forest fires and Climate ChangePublication . Esteves, Filipa; Madureira, Joana; Pires, Joana; Teixeira, João Paulo; Costa, SolangeWildfires have a negative impact on the environment, ecosystems, and human health. Smoke from wildfires contains harmful pollutants such as particulate matter, carbon monoxide, nitrogen dioxide, and volatile organic compounds. These pollutants can cause immediate adverse health effects, mostly related to the respiratory system, such as wheezing, shortness of breath, coughing, and exacerbation of pre-existing health conditions (e.g., asthma, bronchitis, and chronic obstructive pulmonary disease). In addition to short-term health effects, exposure to smoke has also been linked to long-term population health effects. Epidemiological studies have shown a positive association between wildfire smoke exposure and both cardiorespiratory morbidity and all-cause mortality. This has been particularly evident in susceptible populations, including children, older adults, and pregnant women. Thus, it is important to mitigate wildfires’ impact on the human population through prevention and awareness actions. Recently, occupational exposure as a firefighter was listed as carcinogenic to humans (Group 1) by IARC. The proximity of firefighters to wildland fires exposes them to high levels of toxic compounds, making this activity one of the most dangerous in the world. Yet, evidence linking wildland firefighters' occupational exposure and health outcomes is still limited. Characterization of the workplace is an important step for a general perspective of potential risk factors that may influence the parameters considered in further analysis. The increasing risk of wildfires episodes and longer fire seasons highlight the need for occupational studies among these professionals who are commonly exposed to hazardous pollutants. Exposure assessment plays a central role in the identification, evaluation, and control of occupational risks. The exposure is usually assessed through environmental monitoring, where the chemical agents are quantified in environmental samples, as well as through biological monitoring, which consists in the measurement of biological endpoints, commonly called biomarkers. Scientific evidence has contributed to the establishment of measures related with firefighters’ health promotion. Regular monitoring, surveillance and health promotion activities, the introduction of innovative firefighting techniques, safer personal protective equipment and the implementation of written policies and procedures such as decontamination of fire station equipment and spaces are crucial.