Doutorado em Biologia da Relação Parasito-Hospedeiro (IPTSP)
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Item Análise dos genes de virulência cagA, vacA e dupA de Helicobacter pylori e associação com doenças gástrica(Universidade Federal de Goiás, 2021-06-07) Silva, Lucas Luiz de Lima; Carneiro, Lilian Carla; http://lattes.cnpq.br/6506744224041777; Carneiro, Lilian Carla; Silva, Antonio Márcio Teodoro Cordeiro; Gama, Aline Rodrigues; Moraes Filho, Aroldo Vieira de; Santos, Mônica de OliveiraHelicobacter pylori (H. pylori) is a Gram-negative bacterium associated with the development of different gastropathies. The different clinical outcomes of infection by H. pylori are the result of the parasite-host relationship, and the virulence factors produced by the different strains of H. pylori are determinant in the pathogenesis of the infection. Based on the importance of the topic, the aim of this study was to assess the prevalence of H. pylori infection; compare the Polymerase Chain Reaction (PCR) technique with the histopathological examination for the detection of the microorganism; associate the genotypes of cagA, vacA and dupA virulence with the gastropathies presented by the patients and evaluate the origin of the local circulating strains. For this, gastric tissue biopsies from 117 dyspeptic patients were collected and used for DNA extraction. The histopathological examination report of the study patients was also obtained. The screening for H. pylori infection was performed using the 16S rRNA gene (hpx) and the positive H. pylori samples were subjected to the detection and sequencing of the virulence genes vacA, cagA and dupA. The dupA gene sequences obtained from the PCR were used for phylogenetic analysis. The prevalence of H. pylori infection found in this study was 64.1%, when considering only the PCR technique and 72.3% when associated with histopathological examination. A high frequency of positive cagA strains was found (80.0%). The cagA gene was detected in all strains present in patients with severe pathologies, while the isolated vacA gene was not detected in this group. Seriously ill patients had fewer virulence genes in the infecting strain. The presence of the dupA gene in the infecting strain was not associated as a risk factor or a protective factor for gastropathies, however, in women the infection by H. pylori dupA positive, increased the chance of developing gastritis by two. In addition, molecular phylogeny demonstrated that the dupA gene isolated in this study showed homology with genes from H. pylori strains isolated from western countries. The circulating strains of H. pylori in central-western Brazil show high heterogeneity in the frequency of cagA, vacA and dupA virulence genes and the combination of several virulence factors can influence the clinical outcomes of patients.Item Análise da proliferação de amastigotas de Leishmania (Viannia) braziliensis em macrófagos murinos(Universidade Federal de Goiás, 2021-09-30) Teixeira, Mirian Vieira; Oliveira, Milton Adriano Pelli de; http://lattes.cnpq.br/2152513705182408; Oliveira, Milton Adriano Pelli de; Vinaud, Marina Clare; Afonso, Luís Carlos Crocco; Gomes, Clayson Moura; Baeza, Lilian CristianeLeishmania (Viannia) braziliensis is the main species responsible for American tegumentary leishmaniasis in Brazil. However, the use of this parasite species to study Leishmania infection in a murine model has been less conducted when compared to other Leishmania species. Control of murine Leishmania infection has been associated with nitric oxide (NO) produced by inducible NO synthase (iNOS) from M1 macrophage, while arginase expressed by M2 macrophages is related to Leishmania proliferation. The aim of this study was to analyze the ability of L. (V.) braziliensis to proliferate within murine macrophages in vitro for a period of 9 days. Macropha-ges were derived from bone marrow precursors (BMDM) of wild-type mice and were cultured with IFN-γ and LPS, or IL-4, or BMDM iNOS knockout (iNOS KO), and nitric oxide production, arginase activity, and infection with L. (V.) braziliensis. The number of infected macrophages and parasite load were determined by light microscopy. Promastigotes of L. (V.) braziliensis parasites were inoculated (106) into the paw of wild-type and iNOS-deficient mice and lesion progression was measured weekly. Wild-type BMDM were observed to not support proliferation of amastigotes of L. (V.) braziliensis strains after day 3 infection, even within IL-4-treated ma-crophages or iNOS KO macrophages. Arginase activity was higher in iNOS KO macrophages than in IL-4 treated macrophages, showing that the absence of proliferation is arginase inde-pendent. L. (V.) braziliensis was able to cause uncontrolled disease in iNOS KO mice in vivo. The data obtained suggest that murine macrophages do not support proliferation of L. (V.) braziliensis amastigotes, even in the absence of nitric oxide and presence of high arginase ac-tivity. Therefore, further studies related to the requirements of amastigotes internalized in host cells are needed, for the search of better methods to interfere in the diversity of leishmaniasis forms caused by different Leishmania spp.