Evaluation of gtfB gene expression and its relationship with changes in the proteomics profile of Streptococcus mutans in biofilm and planktonic form after growth in the presence of sucrose and starch

Abstract

Streptococcus mutans (S. mutans) is a Gram-positive coccus, which is one of the main causes of tooth infection, including tooth decay and periodontitis. By producing biofilm and changing the content of the proteome, this bacterium causes self-protection and makes the treatment of diseases difficult. Therefore, the aim of this study is to determine the effect of sucrose and starch carbohydrates on gtfB gene expression and its relationship with changes in the proteomics profile of S. mutans in biofilm and planktonic form. Materials and Methods: In the present study, S. mutans ATCC 35668 was cultured in three individual Luria-Bertani media containing sucrose, starch and sucrose-starch and one LB broth without any carbohydrates at 37 for 24-48 hr. Afterwards, the cultured media were employed to assess biofilm formation in a 96-well microtiter plate method and were evaluated to gtfB gene expression using SYBR Green Real Time PCR. In addition, they were einvestigated to effective proteins in colonization using adsorption technique spectroscopy and laser ionization with matrix (MALDI-TOF). Results: The carbohydrates significantly increased the biofilm formation. The abundance of glutamines, adenylate kinase, and 50S ribosomal protein L29 were increased under exposure to sucrose. Upregulation of Lactate utilization protein C, 5-hydroxybenzimidazole synthase BzaA, and 50S ribosomal protein L16 were formed under starch exposure. Ribosome-recycling factor, Peptide chain release factor 1, and Peptide methionine sulfoxide reductase MsrB were upregulated under exposure to sucrose in combination to starch. However, the abundances of some proteins were decreased. Also sucrose, starch, and sucrose-starch in combination, lead to elevated expression rate of gtfB gene associated with colonization.