DSA - Apresentações orais em encontros internacionais
URI permanente para esta coleção:
Navegar
Entradas recentes
- Environmental Water as a Source of Fungal InfectionsPublication . Brandão, JoãoObjectives: The emergence of Candida auris has drawn international attention within the Fungi community, particularly in the context of environmental and occupational health, water management, and research. Currently, wastewater analysis is not limited to COVID-19 investigation but also encompasses other microbial factors like C. auris and Aspergillus fumigatus sensu stricto. The World Health Organization (WHO) addressed fungal taxa in its 2021 recreational water quality management guidelines, recognizing their significance. To enhance human health protection, these guidelines recommend monitoring beach sand for both bacterial indicators of fecal pollution and all fungi as a reflection of contamination levels, indicating the potential exposure of beachgoers to these microorganisms. In 2022, WHO reinforced the need to monitor fungi in national and supranational regulations, introducing a watch list of fungi of interest. Furthermore, Europe updated its Drinking Water Directive and proposed, in a side document designed to help Member-states implement the revised directive (state-of-play) the monitoring of fungi in public buildings used by immunocompromised patients, including hospitals and nursing homes. The objective of this communication is to outline an overview of the current trends of fungal analysis in water environments. Methods: Overview on international policy regulating the presence of fungi in water environments (drinking water, wastewater, coastal and inland recreational water, beach sand). Results: Fungi are missing from all regulation except drinking water in Sweden thus far. The WHO Guidelines for recreational quality recommend looking into fungi, where of relevance, and always on sand. Wastewater and environmental surveillance global initiative (Glowacon) has included fungi in its pathogen list. Conclusions: The recent developments on and categorisation of fungi have paved the way for the inclusion of fungi in water quality regulation, whether for drinking or recreational or wastewater.
- Sand quality as the new criterion of the new Blue Flag recreational water sites in Portugal - It's happening!Publication . Silva, Ana Margarida; Silva, Susana; Sarioglou, Konstantina; Vieira, Márcia; Gonçalves, Catarina; Brandão, JoãoIntroduction: The new WHO guidelines for the quality of bathing waters were published in June 2021, and the chapter on sands was significantly revised compared to the 2003 guidelines. They recommend monitoring enterococci with a provisional limit of 60 MPN/g and a guide value for the total fungal count of 90 CFU/g. The 60 MPN/g sand value was calculated through microbiological risk assessment as equivalent to the reference of 200 MPN/100ml of water, which corresponds to a maximum risk of 5% of developing disease from direct exposure. Based on these guidelines, Portugal’s Blue Flag program decided to implement a new quality criterion for bathing areas in 2024, called “Sand Quality Monitoring.” This criterion was tested for two years without being mandatory, and it was concluded that it would be a good addition to the list of criteria and would not pose a management issue for the beaches. On the contrary, it provides an additional and independent microbiological safety criterion for recreational users, separate from the monitoring of recreational water quality. To implement the new criterion, limits had to be designed for total fungi and E. coli, as the current European directive includes E. coli, and the guidelines for total fungi only provide a guide value, no safety limits. For fungi, the following was defined: 20% of rejection rate, considering the results of Brandão et al. (2021). This represent a guidance value of 89 CFU/g of total fungi in sand but a rejection limit of the 80% percentile, which is 420 CFU/g for coastal beaches and 1130 CFU/g for inland beaches. E. coli serves as an extra faecal indicator, with a reference value of 25 CFU/g (Sabino et al. 2011). Methods: Analytical methods are based on colony counting on sabouraud plates for all Fungi (Sabino et al. (2011)), Quanti-Tray® systems from IDEXXTM (IDEXX, Westbrook, MN, USA) or standard ISO methods (ISO 7899-2 (Boehm et al. 2009) and ISO 9308-1) for enterococci and E. coli and BACTERISK® (MolEndoTech, LTD, Brixham, UK) for the latter. Results (provisional): -Inland and transitional beaches (>1130 CFU/g): 14 out of 43 (32.6%); -Coastal beaches (>420 CFU/g): 17 out of 292 (5.8%) Discussion and conclusions: There is still not enough data to analyse seasonality and regionality comparatively, but…There doesn't seem to be a visible rationale for changes during the bathing season — too many factors influence sand quality and there’s little historical data. Maybe in the future. The values for fecal parameters in Mirandela are low and compliant, but…Total fungi values in Mirandela exceed the 2024 criteria: Homem do Leme, Gondarém and Mamoa exceeded the limits for enterococci contamination more than once; Beaches exceeding fungal limits more than once: Inland beaches: Mirandela, Fraga da Pegada, Ribeira, and Praia fluvial de Reguengos de Monsaraz; Coastal beaches: Homem do Leme, Foz, and Quebrada; Impact: This study shows that it is possible to include sand in the health protection aspects of recreational water quality without loss of the number of safe recreational sites.
- 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.