| Congresso Brasileiro de Microbiologia 2023 | Resumo: 219-1 | ||||
Resumo:Staphylococcus aureus is a bacterium of great interest worldwide being responsible for high levels of hospital and community acquired infections, another important factor is that it is responsible for the rapid increasing of multidrug resistant strains. The infections are initiated by the host’s asymptomatic colonization, where this bacterium start to form biofilms, a complex structure composed by bacteria and extracellular matrix, from biofilms, the bacterium can spread to other tissues causing several diseases. A recent report from WHO pointed that S. aureus is one of the most important bacteria for the development of prophylactic and therapeutics strategies. Even tough, several vaccine candidates have been proposed, until now there is no vaccine approved for humans against these pathogens. The failure on the development for effective vaccines is due to the lack of animal models and correlate of protection the fit on the physiological way the natural course of infection in humans. Based on these limitations, we propose the development of a new selection and validation model for vaccine candidates against Staphylococcus aureus, our model combines bioinformatic, transcriptomic and proteomic analysis of the bacteria in two stages: from colonizing biofilms and biofilm-dispersed, virulent bacteria. For that, we used a cell substrate biofilm formation protocol, which allow the bacterium to form biofilm in a physiological model using lung epithelial cells for 48 h at 34ºC and 5% CO2 (simulating the nasopharynx condition), after this time, the biofilm was treated for 3 h at 38.5ºC (simulating a fever response), as control a 34ºC treated plate was also prepared. After the 3 h, the bacterium was plated on blood agar plates for CFU count, a scanning electron microscopy (SEM)was also performed to evaluate biofilm formation. The results showed that fever simulation works triggering the bacterial dispersion form biofilms two S. aureus strains were tested and for both the heat treatment provided 4 times more dispersion in relation to the control, SEM showed that the cells formed viable, well-structured biofilms. As conclusion, we were able to develop a protocol that simulates a real curse of infection by S. aureus trigged by fever, this result will be used to analyze the bacterium profile during colonization and infection phases. Palavras-chave: multidrug resistance, Biofilm, dispersion, S.aureus Agência de fomento:Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Processo: 400099/2022-5; and Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Processo: 2022/15111-1. | |||||