Poster (Painel)
1593-1Role of Glutamate and Glutamine uptake systems on the pathogenicity of S. mutans
Autores:Roberto Nepomuceno de Souza Lima (USP - Universidade de São Paulo) ; Paulo Henrique Rodrigues (USP - Universidade de São Paulo) ; Ricardo Sergio Couto de Almeida (UEL - Universidade Estadual de Londrina) ; Ewerton Ferreira (USP - Universidade de São Paulo) ; Karine Souza Guimarães (USP - Universidade de São Paulo) ; Maria Regina Lorenzetti Simionato (USP - Universidade de São Paulo) ; Gustavo Henrique Goldman (FCFRP-USP - Faculdade de Ciências Framacêuticas USP) ; Rita de Cássia Café Ferreira (USP - Universidade de São Paulo)


The ability to transport nutrients is a key trait related to bacterial survival on different environments. ATP-dependent transporter systems (ABC transporter family) are highly distribute among bacterial cells and are responsible for the internalization of a different set of nutrients including inorganic phosphate, oligopeptide, polyamine, glutamine, glutamic acid among others. Despite the vital nutritional role, ABC-transporters are involved on the control of virulence-associated traits, as adhesion to host cells. The aim of the present study was to evaluate the in vitro and in vivo effects of the ABC-transporters (glutamate and glutamine uptake systems) in the pathogenicity of Streptococcus mutans, the main cause of tooth decay. Two ABC-transporters were deleted by site-direct mutagenesis. Once selected the two mutant strains were tested for biofilm production, adhesion to IHGK cells (epithelial) and lethality to Galleria mellonella. We observed an increase on the biofilm production of the glutamine uptake mutant strain in the presence of sucrose as carbon source, while no difference was observed regarding the glutamate uptake mutant strain to the wild type UA159 strain. These results accordantly with the increase on the binding of the glutamine uptake mutant to the IHGK cells, in contrast to the glutamate uptake mutant, which showed a reduction in the cell-binding function. G. mellonella larva infected with the glutamine uptake mutant strain showed no difference on the virulence compared to UA159 wild-type strain. In contrast, the glutamate uptake deleted strain was avirulent following inoculation into the larvae. Altogether, the present results indicate the glutamine and glutamate uptake systems show important, but contrasting effects on the pathogenicity of S. mutans. Our results represent the first evidence of the glutamine/glutamate transporters systems on the pathogenicity of S. mutans, which may impact the behavior of this bacterium on dental caries and invasive diseases.

Palavras-chave:  Glutamate, Glutamine, ABC transporter, IHGK cells, Galleria mellonella