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Análise do perfil epidemiológico e molecular do SARS-CoV-2 em dois municípios do estado da Bahia entre 2020 e 2022.

Fri, 22 Aug 2025 00:00:00 GMT

Título: Análise do perfil epidemiológico e molecular do SARS-CoV-2 em dois municípios do estado da Bahia entre 2020 e 2022. Autor(es): Dantas, Anna Carolina Saúde Primeiro Orientador: Marques, Lucas Miranda Abstract: Introduction: Coronavirus Disease 2019 (COVID-19) is a clinically diverse disease caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), whose spread in Brazil was heterogeneous and reflected deep social and regional inequalities. The emergence of viral variants carrying mutations in the genome, particularly in the Spike protein, has influenced transmissibility, clinical severity, and public health impact. Spatial dispersion analysis of the virus requires consideration of both biological and social factors, such as population density and structural inequalities, and is essential for effective genomic surveillance. In this context, investigating circulating viral lineages and individual responses to infection may contribute to control strategies and support the understanding of disease severity and immune responses in confirmed SARS-CoV-2 cases. Objective: To conduct a molecular epidemiological and spatial dispersion analysis of SARS-CoV-2 and evaluate its association with the immune response profile in patients from the municipalities of Vitória da Conquista and Salvador, Brazil. Methodology: Clinical and epidemiological data from patients in Vitória da Conquista (2020–2021) were obtained from the municipal SoulMV health system, while data from patients in Salvador (2022) were collected through a socio-behavioral questionnaire. Descriptive statistical analyses were conducted using Stata version 15.1. Genomic sequencing of samples from both cities was performed using Oxford Nanopore MinION technology and analyzed through bioinformatics for variant typing. In Vitória da Conquista, the expression of innate immunity inflammatory markers was evaluated using qPCR array. In Salvador, genomic dispersion analyses and 3D Spike protein mutation mapping were performed to compare vaccinated and unvaccinated individuals in terms of mutation distribution and potential structural implications. Results: In Vitória da Conquista (n=783), risk factors associated with COVID-19 mortality included being male (p = 0.037), having cardiovascular disease (p < 0.001), diabetes (p = 0.002), chronic obstructive pulmonary disease (COPD) (p = 0.001), and Ct (cycle threshold) values below 22 (p < 0.001). Stratification by disease severity (asymptomatic, mild, and moderate/severe) revealed increased activation of inflammatory pathways in severe cases, including cytokine storm induction and downregulation of anti-inflammatory responses. Genomic analysis indicated the circulation of multiple lineages, including Alpha and Gamma, suggesting successive viral introduction events. In Salvador (n=174), most participants were female (68.9%), aged up to 39 years (50.6%), without comorbidities (66.5%), and users of public transportation (66.5%). Most exhibited mild symptoms (41.5%) and had received a second booster vaccine dose (40.6%). The most prevalent Omicron subvariants were BA.5 (32.57%), BA.4 (21.71%), B (18.86%), and BQ.1 (26.2%). Viral dispersion was predominantly localized, with only a few rapid-spreading events. Mutation analysis revealed distinct profiles between vaccinated and unvaccinated individuals, particularly in the Spike protein, suggesting differential selective pressures. Conclusion: Variation in the clinical profiles of patients affected by COVID-19, influenced by both individual and contextual factors over the course of the pandemic, underscores the importance of identifying and understanding the introduction of new viral lineages. The findings of this study—by revealing circulating strains and the actual local epidemiological scenario—demonstrate that the integration of epidemiological and genomic surveillance is essential for informing more effective public health strategies and guiding targeted governmental actions to control transmission. Editora / Evento / Instituição: Universidade Federal da Bahia Tipo: Tese

IIluminando novas fronteiras: explorando o potencial fotossensibilizador de espécies de Passiflora no controle de infecções por Staphylococcus aureus resistente à meticilina em camundongos senescentes

Tue, 15 Jul 2025 00:00:00 GMT

Título: IIluminando novas fronteiras: explorando o potencial fotossensibilizador de espécies de Passiflora no controle de infecções por Staphylococcus aureus resistente à meticilina em camundongos senescentes Autor(es): Gonçalves, Caroline Vieira Primeiro Orientador: Silva, Robson Amaro Augusto da Abstract: INTRODUCTION: Antimicrobial Photodynamic Therapy (aPDT) has emerged as a potential alternative for the treatment of multidrug-resistant bacterial skin infections, such as those caused by methicillin-resistant Staphylococcus aureus (MRSA), which pose a high risk in elderly individuals. This approach is based on the use of a chemical agent known as a photosensitizer (PS), considered one of the main components of aPDT. OBJECTIVE: This study aimed to evaluate the photosensitizing activity of Passiflora genus extracts, both incorporated and not incorporated into an emulsion, for controlling MRSA infection in vitro and in vivo using a senescence model. METHODOLOGY: The research methodology comprised in vitro and in vivo stages, in addition to the formulation and characterization of a topical emulsion. Initially, in the in vitro assays, the light absorption spectrum of Passiflora extracts and the effective dose for their photoactivation were determined. Additionally, the cytotoxicity of these extracts on eukaryotic cells was evaluated, and the intracellular localization of the butanolic fraction (BF) of P. cincinnata in MRSA was investigated. Subsequently, in the in vivo study, senescent animals intradermically infected in the ear with MRSA were randomly distributed into three experimental groups: Control (receiving only the vehicle); Treated with nonphotoactivated P. cincinnata butanolic fraction (BF); and Treated with photoactivated P. cincinnata BF (APDT). Throughout the in vivo study, cytokine levels in retromaxillary lymph nodes, animal body weight, bacterial load at the infection site, and the degree of ear tissue inflammation were measured. Finally, for the developed topical formulation, a preliminary stability test was conducted, followed by its physicochemical characterization. RESULTS: Passiflora extracts were considered non-cytotoxic to HUVEC (Human Umbilical Vein Endothelial Cells) cell cultures. P. edulis and P. alata extracts showed photosensitizing capacity at a concentration of 1000 µg/mL. The butanolic fraction of P. cincinnata exhibited significant photosensitizing activity at a concentration of 100 µg/mL. Meanwhile, the crude extract (CE) demonstrated this activity at concentrations lower than BF, at 5-50 µg/mL. Isoorientin, the major compound present in P. cincinnata BF, did not show as significant a reduction as P. cincinnata CE and BF. Animals treated with P. cincinnata BF showed better control of bacterial load, less leukocyte infiltration, and less weight loss throughout the MRSA infection process. Furthermore, the APDT group showed a more distinct pattern of cytokine correlations and influence, with a greater number of cytokines exhibiting negative correlations, for example, both among pro-inflammatory cytokines and with the anti-inflammatory cytokine IL-10. Dendrogram analysis and Principal Component Analysis showed that leukocyte levels in the ear are important for the course of infection among the groups, with differences regarding treated or untreated animals. Zeta potential analysis of MRSA revealed that the butanolic fraction of P. cincinnata does not significantly alter the bacterial membrane potential. In the developed formulation, an oil-in-water emulsion compatible system, statistically significant variations did not show changes that would compromise the formulation. The fluidity index values indicated pseudoplastic fluid behavior. Additionally, the emulsion showed thixotropic behavior, a typical characteristic of non-Newtonian fluids. CONCLUSION: The results are promising, given the limited understanding of APDT in senescent animals, and highlight P. cincinnata as a potential photosensitizer against MRSA. This research lays the foundation for developing targeted APDT strategies using Passiflora species and emphasizes the need to explore new photosensitizers derived from underexplored plants. Furthermore, the standardization of a topical formulation, demonstrating stability at room temperature and suitable rheological properties, paves the way for the development of a new therapeutic approach for MRSA skin infections, especially in elderly individuals. Editora / Evento / Instituição: Universidade Federal da Bahia Tipo: Tese

Caracterização da microbiota intestinal, perfil inflamatório e integridade da barreira gastrointestinal de crianças diagnosticadas com transtorno do espectro autista

Tue, 17 Dec 2024 00:00:00 GMT

Título: Caracterização da microbiota intestinal, perfil inflamatório e integridade da barreira gastrointestinal de crianças diagnosticadas com transtorno do espectro autista Autor(es): Brito, Anne Karoline Pereira Primeiro Orientador: Marques, Lucas Miranda Abstract: Introduction: Autism Spectrum Disorder (ASD) is a complex and multifactorial condition that involves social and cognitive deficits in affected individuals. In this context, the study of the gut microbiota has gained relevance, as the microorganisms that compose it interact metabolically, immunologically, and hormonally with the host. Studies on the prevalence of specific strains in the gut microbiota of individuals with ASD are conflicting, and there is still no clear understanding of the microbiota profile in this population or its relationship with intestinal epithelial barrier composition, behavior, and food preferences.Objective: To characterize the gut microbiota and its antimicrobial resistance genes (ARG), as well as to evaluate the eating behavior of children with ASD. Methodology: A non-randomized controlled study was conducted with children diagnosed with autism (ASD) (n=18) and neurotypical children (NT) (n=20). Weight and height data were collected for anthropometric assessment, along with information on gastrointestinal symptoms. Fecal samples were collected for metagenomic sequencing and antimicrobial resistance gene analysis. Relative abundance, alpha diversity, and beta diversity analyses were performed to characterize the microbiota and resistance genes, along with differential relative abundance analysis. Zonulin, Claudin, and Occludin concentrations were analyzed from fecal samples. The Children's Eating Behavior Questionnaire (CEBQ) was used to assess eating behavior, while a 24-hour dietary recall (R24h) was employed to evaluate the level of processing and nutritional quality of foods consumed on the day prior to fecal sample collection. Additionally, blood samples were used to isolate polymorphonuclear cells (PBMCs) and measure TNF-α, IL-6, and IL1-β levels after exposure to lipopolysaccharides (LPS) (1μg/ml) and phytohemagglutinin (PHA) (10μg/ml) for 1 hour and 3 hours.Results: All children in the ASD group reported at least one gastrointestinal symptom. Fecal samples from children with ASD showed significantly lower alpha diversity than those from NT children (p=0.007). PERMANOVA analysis revealed that beta diversity was significantly different between groups (p=0.004), indicating some level of separation between groups in principal coordinate analysis. The genera Staphylococcus, Haemophilus, Brevibacterium, and Bifidobacterium were differentially abundant in children with ASD, whereas Stenotrophomonas and Enterobacter were more differentially abundant in the NT group. Zonulin, Claudin, and Occludin concentrations were significantly higher in the ASD group (p<0.001). Children in the ASD group had significantly lower mean scores in the "Food Selectivity" subscale (p=0.002) compared to NT children. However, they also consumed significantly fewer "salads" and "non-starchy vegetables" while consuming more "sugar-rich or sugar-added foods," "ready-to-eat and semi-processed industrialized foods," "low-nutritional-value beverages," and "fried foods, fatty meats, and fatty sauces" compared to NT children. In the antimicrobial resistance gene (ARG) analysis, an average of 782 genes was identified. The ASD group exhibited greater ARG diversity compared to the NT group (p<0.001). In the inflammatory cytokine analysis, children in the ASD group showed higher TNF-α and IL1-β concentrations at the 3-hour time point compared to the NT group for both LPS and PHA exposure.Conclusion: Children with ASD exhibit physiological alterations that impact their quality of life and responsiveness to treatments and therapies. Reduced microbial diversity, increased gut barrier permeability, and elevated inflammatory cytokine levels in ASD 22 children are key findings for characterizing physiological components in Brazilian children and developing strategies to mitigate these alterations. Editora / Evento / Instituição: Universidade Federal da Bahia Tipo: Tese

Terapia fotodinâmica associada a quercetina microemulsionada como alternativa para o controle de infecções causadas por Staphylococcus aureus resistentes a meticilina

Thu, 12 Dec 2024 00:00:00 GMT

Título: Terapia fotodinâmica associada a quercetina microemulsionada como alternativa para o controle de infecções causadas por Staphylococcus aureus resistentes a meticilina Autor(es): Galantini, Maria Poliana Leite Primeiro Orientador: da Silva, Robson Amaro Augusto Abstract: Objectives: The study aimed to evaluate the antimicrobial effect of quercetin combined with antimicrobial photodynamic therapy (aPDT) and its impact on mice intradermally infected with methicillin-resistant Staphylococcus aureus (MRSA). Additionally, the study involved the standardization of a microemulsion containing quercetin and the assessment of its antimicrobial efficacy after TFA application for MRSA inactivation. Materials and Methods: Initially, in vitro studies were conducted to evaluate the antimicrobial photodynamic potential of quercetin. For this purpose, scanning spectrometry was performed to determine the wavelengths capable of activating quercetin. Subsequently, reference strains of Methicillin-Resistant Staphylococcus aureus (MRSA ATCC 43300) were exposed to various concentrations of quercetin: 100 µg/mL, 300 µg/mL, 400 µg/mL, and 500 µg/mL, and stimulated by blue LED light. The production of singlet oxygen and the zeta potential of bacteria exposed to quercetin were then evaluated to characterize a potential site of action of quercetin on the bacteria. Finally, cytotoxicity analyses were performed on nucleated HUVEC cells. Following these steps, the antimicrobial effects of quercetin as a photosensitizer against S. aureus were evaluated in vivo using a murine model of intradermal infection over 72 hours and 17 days. At this stage, 48 Balb/c mice were intradermally infected in their ears with 1.5x108 colony-forming units of MRSA 43300. After infection, they were divided into four groups (12 animals per group) (1) treated with the vehicle, (2) quercetin alone, (3) blue LED light alone, or (3) with the aPDT protocol (quercetin + blue LED light). Lastly, a microemulsion was developed as a transdermal delivery system for quercetin, with the characterization of the microemulsion system, accelerated stability testing, and antimicrobial evaluation against the MRSA 43300 strain. Results: The scanning spectrophotometry analysis showed a pronounced absorption peak when exposed to blue light in the 400 nm to 450 nm range. This characteristic enabled the conduction of in vitro tests, which revealed significant photodynamic activity against MRSA at concentrations starting from 100 µg/mL. The compound showed an indication of singlet oxygen production by the decrease in uric acid absorption and an indication of action on the bacterial cell wall through the zeta potential test. Furthermore, quercetin did not exhibit toxicity in HUVEC cells before or after photoactivation. In addition, in vivo observations indicated that aPDT with quercetin reduced the bacterial load in the draining lymph node after 72 hours. Despite its efficacy in reducing the bacterial load in the lymph node, the lesion area was more extensive in the groups treated with quercetin, with increased recruitment of polymorphonuclear cells 17 days post-infection. The animals that received treatment with quercetin exhibited immunomodulation with a strong interaction between TNF-α and IL-12p70. Finally, the microemulsion containing quercetin presented a translucent liquid appearance and characteristic particle size, polydispersity index, and zeta potential values of a microemulsion, as well as good stability after 90 days and inhibitory activity against bacterial growth at concentrations of 0.312 mg/mL when photoactivated by blue LED light. Conclusions: Quercetin appears to be a promising photosensitizer in Antimicrobial Photodynamic Therapy (TFA) demonstrating effective photodynamic activity when activated by blue LED light and inducing the death of Staphylococcus aureus both in vitro and in vivo in a murine model of intradermal infection. Furthermore, developing a microemulsion system containing quercetin also stands out due to its favorable physicochemical characteristics, long-term stability, and effective antimicrobial activity against MRSA. This system can develop therapeutic protocols without needing a local photosensitizer injection, reducing associated pain and discomfort and thus potentially decreasing treatment abandonment. Editora / Evento / Instituição: Universidade Federal da Bahia Tipo: Tese