Project description:Rgg-dependent transcriptional regulation in SF370 Streptococcus pyogenes strain was analyzed during post-exponential phase of growth Keywords: rgg mutant
Project description:Streptococcus agalactiae, also known as Group B streptococcus, emerged in the 1960s as a leading cause of septicemia and meningitis in neonates. It is also an increasing cause of infections in adults with underlying diseases. To characterize transcription start sites (TSS) in the hypervirulent ST17 lineage (strain BM110) we used a differential RNA-seq strategy, based on selective Tobacco Acid Pyrophosphatase (TAP) treatment and adapter ligation, which differentiates primary transcripts and processed RNAs
Project description:Streptococcus pneumoniae (pneumococcus) is a major human respiratory pathogen and the leading cause of bacterial pneumonia worldwide. Small regulatory RNAs (sRNAs), which often act by post-transcriptionally regulating gene expression, have been shown to be crucial for the virulence of S. pneumoniae and other bacterial pathogens. Over 170 putative sRNAs have been identified in S. pneumoniae TIGR4 strain (serotype 4) through transcriptomic studies, and a subset of these sRNAs have been further implicated in regulating pneumococcal pathogenesis. However, there was little overlap in the sRNAs identified among these studies, which indicated that the approaches used for sRNA identification were not sufficiently sensitive and robust and that there were likely many more undiscovered sRNAs encoded in the S. pneumoniae genome. Here, we sought to comprehensively identify sRNAs in Avery's virulent S. pneumoniae strain D39 using two independent RNA-seq based approaches. We developed an unbiased method for identifying novel sRNAs from bacterial RNA-seq data and have further tested the specificity of our analysis program towards identifying sRNAs encoded by both strains D39 and TIGR4. Interestingly, the genes for 15% of the putative sRNAs identified in strain TIGR4 including ones previously implicated in virulence were not present in strain D39 genome suggesting that the differences in sRNA repertoires between these two serotypes may contribute to their strain-specific virulence properties. Finally, this study has identified 67 new sRNA candidates in strain D39, 28 out of which have been further validated, raising the total number of sRNAs that have been identified in strain D39 to 112.
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.
