Project description:We have presented FROG and miniFROG reports for the first genome-scale model, iCJ415, for Streptococcus oralis SK141. The model can be found in the Supplementary Material of the publication by Jensen et al, 2020 cited here.
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: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.
