Identificação de proteínas de superfície de Staphylococcus saprophyticus e análise de fatores de virulência

• Autor(a) principal: Carvalho, Alex Jesus de
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/5496
• topic: Staphylococcus saprophyticus; Proteínas de superfície celular; Shaving; Fatores de virulência; Imunogenicidade; Staphylococcus saprophyticus; Cell surface proteins; Shaving; Virulence factors; Immunogenicity; CIENCIAS BIOLOGICAS

The Gram-positive bacterium Staphylococcus saprophyticus, one of the coagulasenegative staphylococci, is the second most common causative agent of urinary tract infection, affecting mainly sexually active women. Staphylococcus saprophyticus can cause acute diseases as pyelonephritis, sepsis, nephrolithiasis, endocarditis, urethritis, epididymitis and prostatitis. This work aims to identify Staphylococcus saprophyticus surface proteins by using a proteolytic shaving approach, a methodology that was established to identify surface-exposed protein domains by tripsinization of intact cells. The peptides obtained were treated by trypsin, reduced, alkylated and identified by nano-chromatography using a nanoACQUITY UPLCTM system (Waters) coupled to a SYNAPT Q-TOF mass spectrometer (Waters). The homology analysis was performed using the software ProteinLynx 2.3 (Waters). Through the shaving, it was possible to identify 219 proteins, many of them, described as virulence factors. Of total, 01 is cell wall protein, 09 are extracelular proteins, 19 are membrane proteins and 190 are citoplasmatic proteins. Besides of the lysis process, the presence of cytoplasmic proteins on cell surface can be due to the activity of export pathways not yet identified and many of these proteins can be proteins with moonlighting function, in other words, proteins that plays more of one function, it can, in this case, plays functions on S. saprophyticus cell surface related to bacterial virulence. The main proteins with moonlighting function include metabolic enzymes of the glycolytic pathway; enzymes of other metabolic pathways, such as, glyoxalate cycle; chaperones and proteins related with the proteic folding. The prediction of cellular localization was performed through LocateP database. The results of this research help to elucidate the strategies and machineries used by proteins during the adhesion, infection and proliferation, leading us to understand the interaction between the pathogenic bacteria S. saprophyticus and the human host. The knowledge about the proteins present on the cell surface is of extreme importance, because many of these proteins represent targets to new drugs, therapeutic antibodies or vaccines, since the pathogen cell surface is the first to contact with the host cells during the infection process.