Análises proteômicas de cepas de Staphylococcus saprophyticus elucidam diferentes estratégias para virulência e infecção

• Autor(a) principal: Silva, Karla Christina Sousa
• Data de Publicação: 2019
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/12205
• topic: Proteômica; Staphylococcus saprophyticus; Virulência; Infecção; Staphylococcus saprophyticus; Virulence; Infection; Proteomics; CIENCIAS BIOLOGICAS::MICROBIOLOGIA::BIOLOGIA E FISIOLOGIA DOS MICROORGANISMOS::BACTEROLOGIA

Staphylococcus saprophyticus is a gram positive, coagulase negative bacteria and is one of the most common etiological agent of urinary tract infections (UTI) among sexually active young females. The infection may be led mainly by sexual intercourse. Little is known about the molecular features of S. saprophyticus infection model. However, plasticity in the proteomic profile is detected in the genus Staphylococcus and can be related with infection ability. In this study, we aimed to analyze the metabolic differences among three different pathogenic strains of S. saprophyticus (ATCC 15305, 7108 and 9325) using proteomics approaches. The proteomic data revealed variations among the strains that may lead to different responses in the context of an infection. There are differences in the carbohydrate metabolism, amino acid metabolism and pathogen defense against host defenses. Thioredoxin was one of the differentially expressed proteins among strains, thiol level assays showed similar levels of reduced thiol for ATCC15305 and 9325 strains, in contrast 7108 strain showed considerably low levels of reduced thiol levels when compared to the other analyzed strains. Urease is one of the main virulence factors of S. saprophyticus. The cytoplasmatic urease concentrations varied considerably. The 9325 strain had the lowest cytoplasmatic urease activity, however when plated on ureabased agar it showed a high urease activity, which means that probably most of the urease synthesized is exported to the extracellular milieu. Another important feature is related to the purine metabolism operon, which is highly regulated on ATCC15305 and exerts an influence upon the biofilm production in this strain. These results show that, although belonging to the same species, different S. saprophyticus strains present diverse behavior in response to different contexts that the microorganism may face in the host.