Project description:This study provides a comprehensive genomic characterization of Streptococcus oralis CRC211, a novel bacterial strain isolated from colorectal tumor tissue, through whole-genome sequencing and comparative analysis. The high-quality assembled genome (15.03 Mb, 40.94% GC content) contains 2 prophage regions spanning 160.5 kb, which may facilitate horizontal transfer of virulence genes. Functional annotation identified 3,674 genes, with significant enrichment in metabolic pathways (amino acid and carbohydrate metabolism) and virulence factors (116 genes in VFDB), including adhesins and biofilm-associated proteins that likely promote tumor colonization. Comparative genomic analysis revealed CRC211 shares 92.29% average nucleotide identity with reference S. oralis strains, while pan-genome analysis demonstrated an open genome structure with 1,222 conserved core genes. The strain also carries 75 antimicrobial resistance genes, suggesting potential clinical relevance. Notably, the genomic profile indicates adaptations for nutrient acquisition and immune evasion in the tumor microenvironment. These findings establish CRC211 as a CRC-associated strain with distinct genomic features that may contribute to tumor progression, providing crucial insights for future investigations into its oncogenic mechanisms and potential applications in microbiota-based diagnostics or therapeutics for colorectal cancer.
Project description:We compared the gene expression patterns of macrophages infected with S. oralis wild type and SpxB KO, a strain that does not produce H2O2.
Project description:Human gingival epithelial cells (HGEp) and fibroblasts (HGF) are the main cell types of the peri-implant soft-tissue, with HGEp constantly being exposed to bacteria and HGF residing protected in the connective tissue as long as an intact mucosa-implant seal is preserved. Streptococcus oralis belongs to the commensal bacteria, is highly abundant at healthy implant sites, and might exert host modulatory effects on soft-tissue cells as described for other streptococci. Thus, we aimed to investigate the effects of S. oralis biofilm on HGEp as well as HGF. HGEp or HGF were grown on titanium separately and responded to S. oralis biofilm challenge. The cell condition of HGF was dramatically impaired after 4 hours showing a transcriptional inflammatory and stress response. In contrast, S. oralis challenge induced only transcriptional inflammatory response in HGEp with their cell condition remaining unaffected. Subsequently, HGF were susceptible compared to HGEp. The proinflammatory IL-6 was attenuated in HGF and CXCL8 in HGEp indicating a general tissue-protective role of S. oralis, forasmuch as the HGF are not exposed. In conclusion, an intact implant-mucosa interface is a prerequisite so that commensal biofilms can promote homeostasis for tissue protection.
Project description:Investigation of whole genome gene expression level changes in S. pneumoniae KCTC 5080T, S. mitis KCTC 3556T, S. oralis KCTC 13048T, and S. pseudopneumoniae CCUG 49455T. This proves that transcriptional profiling can facilitate in elucidating the genetic distance between closely related strains. A one chip study using total RNA recovered from S. pseudopneumoniae CCUG 49455T with three strain. For the the transcriptome of S. pseudopneumoniae CCUG 49455T was analyzed using the S. pneumoniae R6 microarray platform and compared with those of S. pneumoniae KCTC 5080T, S. mitis KCTC 3556T, and S. oralis KCTC 13048T strains.