Clonagem e expressão heteróloga do antígeno SsaA de Staphylococcus saprophyticus e avaliação da secreção durante interação com macrófagos

• Ano de defesa: 2016
• Autor(a) principal: Rosa, Isabella I. R.
• Orientador(a): Rocha, Juliana Alves Parente
• Banca de defesa: Rocha, Juliana Alves Parente , Paccez, Juliano Domiraci, Amaral, Andre Correa
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Programa de Pós-graduação em Genética e Biologia Molecular
• Departamento: Instituto de Ciências Biológicas - ICB (RG)
• País: Brasil
• Palavras-chave em Português: Staphylococcus saprophyticus; Proteína secretada; Infecção; Fagocitose; Clonagem molecular
• Palavras-chave em Inglês: Staphylococcus saprophyticus; Secreted protein; Infection; Phagocytosis; Molecular cloning
• Área do conhecimento CNPq: BIOQUIMICA::BIOLOGIA MOLECULAR
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tede/6198

Staphylococcus saprophyticus is a pathogenic bacterium of the urinary tract and the main etiological agent of urinary tract infections by Gram-positive bacteria. Although S. saprophyticus potentially can cause serious infections such as pyelonephritis, septicemia, endocarditis and nephrolithiasis, and also multidrug resistance has been reported, not much is known about the mechanisms used by this bacterium during infection. Secreted proteins might be essential on those mechanisms if their role is accomplished during phagocytosis by their assistance of an active infection in phagocytic cells, protecting against oxidative stress and increasing the persistence of bacterial cells within phagocytes, and / or causing lysis of the host cell. Recently our group identified the immunogenic protein SsaA in the secretome of S. saprophyticus. This protein had been previously identified in S. aureus proteome, and it appears to be controlled by regulatory systems for known virulence factors. It also presents similarities with lytic proteins and proteins that assist the persistence within phagocytic cells. However, no approach had analyzed the contribution of SsaA during infection, therefore, through the construction a cloning vector containing the S. saprophyticus gene ssaA, heterologous expression of the recombinant protein and the production of specific polyclonal antibodies, it was able to verify the interaction of SsaA and proteins from macrophages infected by bacterial cells. Through immunofluorescence microscopy, it was verified that the dispersion of SsaA is not limited to phagocytic cells but it was throughout their cytoplasm after internalization of the bacterium. These findings together with other evidence in the literature suggest that SsaA is used during infection by S. saprophyticus, more specifically during phagocytosis. Further approaches are required to confirm if SsaA has a lytic activity and also characterize this protein as a virulence factor, contributing to elucidate strategies used by S. saprophyticus during infection in the human host.