TEDE Communidade:
http://www.bdtd.uerj.br/handle/1/3561
2024-03-29T12:59:25ZEstrutura populacional e cenário evolutivo do patógeno multirresistente Enterococcus faecium em instituições hospitalares do Rio de Janeiro
http://www.bdtd.uerj.br/handle/1/21073
Título: Estrutura populacional e cenário evolutivo do patógeno multirresistente Enterococcus faecium em instituições hospitalares do Rio de Janeiro
Autor: Souza, Stephanie da Silva Rodrigues
Primeiro orientador: Merquior, Vânia Lúcia Carreira
Abstract: Enterococcus faecium stands out as an opportunistic pathogen frequently associated with hospital-acquired infections around the world. The aim of this study was to determine the population structure among E. faecium isolates recovered in hospitals of Rio de Janeiro city, Brazil, over a period of eight consecutive years (2009 to 2016) and to evaluate the genetic events related to the evolution of hospital-adapted clonal lineages. The bacterial isolates were initially characterized according to their susceptibilites to antimicrobial agents, evaluated by the disk-diffusion method, and to the presence of genetic determinants associated with resistance to antimicrobial agents and with virulence, investigated by PCR assays. Based on the results obtained, 52 strains were subsequently selected for whole-genome sequencing (WGS) using the Illumina Hiseq platform. In addition, another 22 strains belonging to the hospital-adapted lineage ST78, previously predominant in the city hospital institutions, were included for comparative purposes. An extensive pipeline of bioinformatics tools was implemented to reconstruct phylogenetic relationships and analyze different genetic aspects of the evolution of the 74 strains studied. Phylogenetic analyses indicated the occurrence of multiple lineage changes over time. ST78 was predominant among isolates recovered from 2002 to 2008, being replaced by the emergence of ST412. This lineage was predominant until 2012, when two new lineages have emerged: ST963 in 2013, and ST896 in 2015. Genome analyses revealed different mechanisms associated with the evolution of these lineages. ST78 had its emergence and expansion associated with the enlargement of the acessory genome, with a high number of insertion sequences (ISs) and prophages. Moreover, the exclusive presence of a toxin-antitoxin system, involved in the stabilization of mobile genetic elements (MGE), corroborated these findings. On the other side, the emergence of ST412, observed in two distinct waves, was associated with several recombination events in the ancestor nodes. Additionally, a high number of SNPs, possibly related to the formation of hypermutantes due to a stop codon acquisition in a DNA repair system, and the exclusive acquisition of cell wall biogenesis genes, were associated with the expansion of this lineage. Recombination events in the ancestor nodes were detected in the ST963 and ST896 lineages. ST896 had the lowest number of acessories genes, but a frequent presence of antibiotic resistance was strongly associated with this group. The expansion of ST963 was accompanied by the exclusive acquisition of genes related to amino acid metabolism and biosynthesis of secondary metabolites. A large number of genetic novelty units (GNU) was observed in this group. Some features such as the presence of drfF gene (trimethoprim resistance), virulence determinant hyl, the ISLgar5 and the allele 44 to purK gene were also related to the lineages that replaced ST78. Overall, our results indicate that the E. faecium population investigated has undergone successive lineage replacement in a dynamic evolutionary process. The data highlighted the different genetic events that may play a role in the emergency of specialized subpopulations adapted to the hospital environment and endorse the need of continuous monitoring the infections caused by this microorganism
Instituição: Universidade do Estado do Rio de Janeiro
Tipo do documento: Tese2020-09-14T00:00:00ZRemodelamento do tecido hepático e do tecido adiposo em camundongos Swiss Webster na esquistossomose aguda e submetidos à dieta hiperlipídica
http://www.bdtd.uerj.br/handle/1/21046
Título: Remodelamento do tecido hepático e do tecido adiposo em camundongos Swiss Webster na esquistossomose aguda e submetidos à dieta hiperlipídica
Autor: Ubirajara, Thainá de Melo
Primeiro orientador: Neves, Renata Heisler
Abstract: Dyslipidemia and schistosomiasis are considered a serious public health problem today, affecting about 2.5 million people in Brazil and more than 240 million worldwide. Thus, in order to better understand the pathological process of schistosomiasis, the remodeling of liver and adipose tissue in experimental acute schistosomiasis in female Swiss Webster mice submitted to the high-fat diet and their respective controls was evaluated. Female mice received a high-fat diet (29% lipids) or a standard diet (12% lipids) and after 5 months were infected subcutaneously with 100 cercariae of Schistosoma mansoni (BH strain). After 9 weeks of infection, the animals were euthanized and blood samples were collected for biochemical analysis. The content of the peritoneal lavage was removed to check the pattern of immune response present in the macrophages, for this purpose the cytokines with pro-inflammatory, anti-inflammatory and chemokine MCP-1 were dosed. The liver and visceral adipose tissue were removed, weighed and subjected to routine histological processing. We used Hematoxylin & Eosin, Lennert’s Giemsa, Gomori Reticulin and Picrosirius Red stains to perform histopathological analyzes; stereological, morphometric; verification of cell composition and quantification of granuloma collagen. The data were analyzed by the Mann-Whitney test or by the ANOVA analysis of variance with Tukey-Kramer post-test. Biochemical analysis confirmed the condition of dyslipidemia in animals fed a high-fat diet, however, lipid and glucose concentrations were significantly lower in infected animals. Schistosomal infection stimulated different hematopoietic lineage and induced an immune response directed to the pro-inflammatory profile. The infected groups had greater liver mass regardless of the diet introduced. In addition, E both liver and adipose tissue showed changes in morphological architecture, due to an intense inflammatory process. The morphometric analysis of the centrilobular and hepatic veins revealed that both the high-fat diet and schistosomal infection affected the parameters and morphometry of these considered vessels. We conclude that diet-induced dyslipidemia interferes with some parameters of experimental acute infection, as it promotes the remodeling of the immune profile of cytokines produced by macrophages, the disruption of liver and adipose tissue and the modulation of the morphometric parameters of centrolobular and veins hepatic
Instituição: Universidade do Estado do Rio de Janeiro
Tipo do documento: Dissertação2020-05-05T00:00:00ZAnálise fenotípica e genotípica de cepas de Escherichia coli Uropatogênicas (UPEC) isoladas de pacientes da nefrologia do Hospital Universitário Pedro Ernesto (HUPE)
http://www.bdtd.uerj.br/handle/1/21038
Título: Análise fenotípica e genotípica de cepas de Escherichia coli Uropatogênicas (UPEC) isoladas de pacientes da nefrologia do Hospital Universitário Pedro Ernesto (HUPE)
Autor: Souza, Lucieny de Faria
Primeiro orientador: Ignácio, Ana Cláudia de Paula Rosa
Abstract: Invasion of bacteria capable of causing cystitis and / or pyelonephritis characterizes UTI. Escherichia coli is the main bacterial species associated with this infection, due to its importance in causing UTI, and some of this species are called UPEC (Uropathogenic Escherichia coli). In the present study, 11 UPEC strains isolated from urine of patients from the HUPE nephrology clinic with symptomatic or asymptomatic infections were studied. The presence of 5 virulence factors was investigated through simple and multiplex PCR techniques to verify the genes encoding adhesins P (pap), fímbria S (sfa), sideroforo (aerobactinin) and alpha-hemolysins (hly); islands of pathogenicity (virulence) through the PAI marker. The antimicrobial resistance profiles and presence of the main resistance genes such as blaNDM-1, blaVIM-1, blaIMP-1, blaKPC (genes encoding the production of metalobetalactamase enzymes) were evaluated; blaCTX (encoding ESBL) and oxa-48 gene (which encodes the production of OXA-carbapenemase). To investigate the pathogenesis of these infections, we used the adhesion and invasion tests in VERO cells where we had 100% adherence and invasion, as well as the use of scanning electron microscopy (SEM), as a methodological alternative for the registration of adhesion and invasion of E in VERO cells. The strains of UPECs tested did not present virulence factors, or had at least one of these factors. We used to characterize the clonal relationship of the strains studied in the study of pulsed field electrophoresis (PFGE) and the phylogenetic relationship by determining the groups A, B1, B2 and D of these microorganisms, which presented as a prevalence of groups D followed by B2. The joint analysis of these data contributed to determine, together with the formation of biofilm and the resistance, that there is no relationship between each other, all these analyzed parameters
Instituição: Universidade do Estado do Rio de Janeiro
Tipo do documento: Tese2018-11-09T00:00:00ZA influência da antibioticoterapia na tricuríase em fase crônica
http://www.bdtd.uerj.br/handle/1/20967
Título: A influência da antibioticoterapia na tricuríase em fase crônica
Autor: Silva, Alessandra Campos da
Primeiro orientador: Torres, Eduardo José Lopes
Abstract: Geohelminthiasis are parasitic infections caused by nematodes and transmitted by direct or indirect contact of the host with soil contaminated with human feces. Human trichuriasis is developed by the species Trichuris trichiura. T.muris has been used as an experimental model and has proven to be a powerful tool for exploring infection establishment and maintenance processes. The effectiveness of drugs used against geohelminthiasis has diminished over time as they are widely distributed for preventive chemotherapy, so the threat of resistance is real and immediate. There is a need to study new forms of treatment for soil-borne diseases. This study aims to evaluate the impact of antibiotic therapy on the parasitic biology of Trichuris muris, and the effects of this drug on tissue changes caused by infection and its influence on the intestinal microbiota and the bacteria associated with the process of tissue invasion as a result of this parasitosis. Male mice (swiss webster) were infected with 150 T. muris eggs. After infection was established, the animals were treated with subcutaneous Piperacillin + Tazobactan (8mg / day) for eight days. Stool samples were collected for parasitological examination and after 45 days the animals were euthanized and necropsied. Different tissues were collected and processed for hematological / biochemical, immunological and histopathological techniques. Our results show that the treatment had no impact on the parasite's reproductive biology, fecal egg clearance and parasite load. As expected, the infected animals presented a significant thickening of the intestinal mucosa, submucosa and muscular layer, where we characterized a polymorphonuclear infiltrate, with few macrophages, in the intestinal mucosa and submucosa an intense polymorphonuclear and lymphoplasmic infiltrate. Antibiotic therapy promoted a significant reduction in epithelial submucosa thickening, reducing the inflammatory infiltrate, with few cells identified in this layer. In the immunological aspects we observed a decrease in IL-10 production in the infected animals serum treated and a reduction of IL-6 and an increase of TNF and INF- in the mesenteric lymph node and serum of this group. There was an increase in IL-6 in the caecum of infected animals compared to those treated. Regarding Th2 cytokines, our data suggest, even without significant difference, a reduction in IL-4 and IL-10 release in the serum of infected animals undergoing treatment. Invasive bacteria were identified only in the submucosa of untreated infected and control animals as well as the presence of enterobacteria was observed only in these two groups. We conclude that antibiotic therapy has no impact on nematode reproductive activity or parasite load, indicating that this drug has no action against the parasite. However, the treatment significantly reduced intestinal bacterial colonization and this resulted in the elimination of the bacterial invasion process in the epithelial submucosa, providing a significant reduction in the intestinal inflammatory infiltrate. We found that chronic trichuriasis develops a more serious infectious aspect due to the synergism that occurs between adult worm lesions and invasion of opportunistic bacteria.
Instituição: Universidade do Estado do Rio de Janeiro
Tipo do documento: Dissertação2019-06-07T00:00:00Z