Project description:Transcriptional comparisons between wild-type Streptococcus mutans UA159 and two mutant strains (M-bM-^HM-^FackA and M-bM-^HM-^FackA pta). On growth condition in defined FMC medium, WT vs. either M-bM-^HM-^FackA or M-bM-^HM-^FackA pta mutants. Biological replicates: 10 control, 5 each mutant, independently grown and harvested. One replicate per array.
Project description:Transcriptional profiling of early logarithmic phase culture (O.D=0.2-0.3) of Streptococcus mutans UA159 comparing control of untreated Streptococcus mutans UA159 bacteria with Streptococcus mutans UA159 bacteria spplemented with 20µM synthetic DPD (pre-AI-2) which regulates gene expression via AI-2 quorum sensing system.Three compairisons were performed at pHs of 7,6 and 5.
Project description:RNA-Seq was used to compare the transcriptome of Streptococcus mutans UA159 during growth alone in monoculture, in coculture with Streptococcus gordonii DL1, Streptococcus sanguinis SK36 or Streptococcus oralis 34, and in a quadculture containing all four species. Individual cultures of commensal species Streptococcus gordonii DL1, Streptococcus sanguinis SK36 and Streptococcus oralis 34 were sequenced as well. This revealed a common transcriptome pattern in S. mutans when grown in mixed-species culture, indepenedent of the species identity that S. mutans was cultured with. Additionally, transcriptome changes in the commensal species could also be determined when undergoing competition from S. mutans. RNA-Seq was used to compare the transcriptome of Streptococcus mutans UA159 during growth alone in monoculture or in coculture with Streptococcus sobrinus NIDR 6715, Lactobacillus casei ATCC 4646 or Corynebacterium matruchotii ATCC 14266. These data were compared to previous coculture and quadculture RNA-Seq data with commensal streptococci (GSE209925). These data confirmed a common transcriptome pattern in S. mutans when grown in mixed-species culture with commensal streptococci that is not present with non-commensal streptococci, indepenedent of the species identity that S. mutans was cultured with.
Project description:Streptococcus mutans, an oral pathogen associated with dental caries, colonizes tooth surfaces as polymicrobial biofilms known as dental plaque. S. mutans expresses several virulence factors that allow the organism to tolerate environmental fluctuations and compete with other microorganisms. We recently identified a small hypothetical protein (90 amino acids) essential for the normal growth of the bacterium. Inactivation of the gene, SMU.2137, encoding this protein caused a significant growth defect and loss of various virulence-associated functions. An S. mutans strain lacking this gene was more sensitive to acid, temperature, osmotic, oxidative, and DNA damage-inducing stresses. In addition, we observed an altered protein profile and defects in biofilm formation, bacteriocin production, and natural competence development, possibly due to the fitness defect associated with SMU.2137 deletion. Transcriptome sequencing revealed that nearly 20% of the S. mutans genes were differentially expressed upon SMU.2137 deletion, thereby suggesting a pleiotropic effect. Therefore, we have renamed this hitherto uncharacterized gene as sprV (streptococcal pleiotropic regulator of virulence). The transcript levels of several relevant genes in the sprV mutant corroborated the phenotypes observed upon sprV deletion. Owing to its highly conserved nature, inactivation of the sprV ortholog in Streptococcus gordonii also resulted in poor growth and defective UV tolerance and competence development as in the case of S. mutans Our experiments suggest that SprV is functionally distinct from its homologs identified by structure and sequence homology. Nonetheless, our current work is aimed at understanding the importance of SprV in the S. mutans biology.
