IADR Abstract Archives
Effect of Streptococcus gordonii luxS System on Streptococcus mutans Transcriptome
Objectives: LuxS/autoinducer-2 (AI-2) system can mediate interspecies interactions in oral microbial community. This study was to investigate the effect of Streptococcus gordonii luxS system on Streptococcus mutans transcriptome, using RNA-seq.
Methods: A 24-well plate inserted with transwells (0.4µm pore polycarbonate membrane) was used for single and dual-species biofilm formation. S. mutans UA159 was inoculated into a 24-well plate to form a 48-h biofilm in BHI containing 0.5% sucrose. S. gordonii ATCC35105 and its isogenic luxS mutant strains in the same medium were added into transwells (0.4µm pore size) and placed on top of the wells containing S. mutans UA159 culture. A biofilm medium alone group was added as the negative control. After 48 h, S. mutans biofilms were collected for total RNA extraction and cDNA paired-end sequenced (Illumina Hiseq sequencing). Differentially gene expression analysis was carried out. A change of 1.5-fold was set as the threshold of differential gene expression (FDR< 0.05).
Results: The data indicated in the presence of S. gordonii, genes related to sucrose-specific PTS, glucose-specific PTS and fructose-specific PTS were up-regulated in S. mutans biofilms; whereas genes associated with tricarboxylic acid cycle and F1F0-ATP were down regulated. In comparison to the group with the addition of S. gordonii wild type, genes associated with lactose-specific PTS and Pst system were down-regulated in S. mutans biofilms with the addition of S. gordonii ΔluxS strain.
Conclusions: When cultured with S. gordonii, a complex regulation on carbohydrate metabolism and acid tolerance in S. mutans biofilms was observed. S. gordonii LuxS/AI-2 system may participate in the interaction of bacteria through the lactose-specific pathway and Pst system of S. mutans.
Methods: A 24-well plate inserted with transwells (0.4µm pore polycarbonate membrane) was used for single and dual-species biofilm formation. S. mutans UA159 was inoculated into a 24-well plate to form a 48-h biofilm in BHI containing 0.5% sucrose. S. gordonii ATCC35105 and its isogenic luxS mutant strains in the same medium were added into transwells (0.4µm pore size) and placed on top of the wells containing S. mutans UA159 culture. A biofilm medium alone group was added as the negative control. After 48 h, S. mutans biofilms were collected for total RNA extraction and cDNA paired-end sequenced (Illumina Hiseq sequencing). Differentially gene expression analysis was carried out. A change of 1.5-fold was set as the threshold of differential gene expression (FDR< 0.05).
Results: The data indicated in the presence of S. gordonii, genes related to sucrose-specific PTS, glucose-specific PTS and fructose-specific PTS were up-regulated in S. mutans biofilms; whereas genes associated with tricarboxylic acid cycle and F1F0-ATP were down regulated. In comparison to the group with the addition of S. gordonii wild type, genes associated with lactose-specific PTS and Pst system were down-regulated in S. mutans biofilms with the addition of S. gordonii ΔluxS strain.
Conclusions: When cultured with S. gordonii, a complex regulation on carbohydrate metabolism and acid tolerance in S. mutans biofilms was observed. S. gordonii LuxS/AI-2 system may participate in the interaction of bacteria through the lactose-specific pathway and Pst system of S. mutans.