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- Surveillance of invasive meningococcal disease in Portugal, from 2020 to 2024Publication . Bettencourt, Célia; Nunes, A.; VigLab-DM – Network for the Laboratory Surveillance of Meningococcal Disease; Bajanca-Lavado, M.P.; .Introduction: Since 2002, laboratory surveillance of Invasive Meningococcal Disease (IMD) has been carried out by the National Reference Laboratory for Neisseria meningitidis, at the National Institute of Health Doutor Ricardo Jorge, Portugal. This study aims to analyse the epidemiology of IMD and the genetic diversity of Neisseria meningitidis strains from 2020 to 2024. Material and Methods: Suspected IMD cases and N. meningitidis isolates were sent to the reference laboratory for confirmation and strain characterization. Invasive isolates were characterized by WGS (Illumina) and sequences were submitted to the PubMLST/Neisseria database. Results: Between 2020 to 2024, 125 IMD cases were confirmed. Annual incidence rate ranged from 0.36 cases/100,000 inhabitants in 2020 to 0.32 in 2023 [1, 2]. Serogroup B was the most prevalent (49.6%), followed by serogroups Y (14.4%), W (13.6%) and C (5.6%). Serogroup W mainly affected those over 45 years old (58.8%). In silico analysis of 89 (71.2%) isolates identified major clonal complexes (cc): B-cc213 (22%) and cc41/44 (18%), Y-cc23 (80%), W-cc11 (66.7%), and C-cc11/cc103 (33.3% each). Conclusions: Compared to previous studies (2003-2020), the incidence of IMD in Portugal has decreased [1-3]. However, serogroup B remains the leading cause of IMD, raising concerns, particularly due to cases in children and emerging clusters with low vaccination coverage (e.g. serogroup B cc213) [4]. In contrast, serogroup W cases have increased, especially among adults [2, 3]. This study highlights the importance of laboratory surveillance for understanding IMD epidemiology and monitoring long-term trends.
- Molecular characterization of Neisseria meningitidis strains causing non-invasive disease in Portugal from 2012-2024Publication . Bettencourt, Célia; Camões, InêsIntroduction: Non-invasive meningococcal disease (NIMD) is not notifiable, and the prevalence of serogroups and antimicrobial resistance (AMR) are unknown. This study aims to investigate the genetic diversity of non-invasive isolates identified in Portugal (2012-2024), assess their genomic relationships with Portuguese invasive isolates and identify AMR profiles. Material and Methods: All non-invasive N. meningitidis isolates were characterized by whole genome sequencing and the sequences submitted to the PubMLST/Neisseria.database. For antimicrobial susceptibility testing, antibiotic gradient strip diffusion (Etest) was used. Results: A total of 141 non-invasive isolates were characterized by WGS with 88% identified from respiratory secretions. Serogroup B was the most prevalent (40.4%), followed by serogroups Y (10.6%), C and E (3.5% each), W, X and Z (1.4% each). Capsule null (cnl) isolates accounted 33.3%. In silico analysis revealed the main clonal complexes (cc): B-cc41/44 (21%) and cc162 (14%), Y-cc23 and cc103 (33.3% each) and cnl-cc53 (38.3%). Isolates belonging to cc11 were predominantly serogroup C (40%) and only 1 isolate was identified as serogroup W. All isolates were sensitive to ceftriaxone and 67.9% of the isolates were penicillin-nonsusceptible, while 2.9% and 3.9% were resistant to ciprofloxacin and rifampicin, respectively. Conclusions: In this study, we identified non-invasive populations with similar genetic diversity when compared to invasive populations in previous studies[1]. In contrast, NIM isolates showed increased levels of resistance to penicillin and several isolates showed resistance to antibiotics used in IMD prophylaxis. These results emphasise the need for more studies on AMR among meningococci in order to ensure the effective use of antibiotics in the treatment of meningococcal disease.
- Tabela da Composição de AlimentosPublication . Dias, Maria da GraçaApresentação sobre a Tabela da Composição de Alimentos, a Plataforma PortFIR e a importância das Bases de Dados da Composição de Alimentos.
- Familial HypercholesterolaemiaPublication . Alves, Ana Catarina; Medeiros, AnaA clinical case study presentation on Familial Hypercholesterolemia, presented within the framework of Biochemistry and Biomedicine.
- Métodos Laboratoriais para Avaliação da Toxicidade: Uma Abordagem PráticaPublication . Rego, AndreiaA palestra aborda métodos laboratoriais para avaliação da toxicidade, destacando os ensaios de viabilidade, citotoxicidade e morte celular, com foco prático no ensaio de MTT. Explicou-se o princípio do MTT, onde células metabolicamente ativas reduzem o sal MTT a cristais de formazan, permitindo avaliar a viabilidade celular por espectrofotometria. Foram ainda discutidas aplicações do MTT em monitorização de crescimento celular, avaliação de citotoxicidade de compostos e determinação de IC50, ilustrando a importância destes ensaios em estudos de toxicidade e eficácia de compostos. Foram apresentados os passos práticos do ensaio, desde a preparação das células, aplicação dos compostos, incubação com MTT, solubilização dos cristais com DMSO até à leitura dos resultados, incluindo o cálculo de viabilidade e análise de curvas dose-resposta. Por fim, discutiram-se vantagens (simplicidade, baixo custo e reprodutibilidade), limitações (sensibilidade a interferências e incapacidade de distinguir tipos de morte celular) e soluções, reforçando a necessidade de controlos e uso de ensaios complementares para validar resultados em toxicologia experimental.