Project description:A methyl-specific metabolic labeling approach for global methylome mapping and found extensive His methylation at C3H1 zinc fingers.
Project description:Bifidobacterium breve represents one of the most abundant (bifido)bacterial species in the gastro-intestinal tract of (breast-fed) infants, where their presence is believed to be beneficial. In the present study whole genome sequencing, employing PacBio’s Single Molecule, Real-Time (SMRT) sequencing platform, combined with comparative genome analysis allowed the most extensive genetic investigation of this taxon. Our findings demonstrate that Restriction/Modification (R/M) systems constitute a substantial part of the B. breve variome. Availing of the methylome data generated by SMRT sequencing, combined with targeted Illumina bisulfite sequencing (BiSeq) and comparative genome analysis, we were able to detect methylation recognition motifs and assign these to identified B. breve R/M systems, where in several cases such assignments were confirmed by restriction analysis. Furthermore, cloning of a selected methyltransferase-encoding gene validated the activity of the corresponding R/M system, and was shown to overcome the barrier they impose to genetic accessibility, thus allowing future genetic manipulation of members of this species.
Project description:The custom-made S. epidermidis GeneChips(Shanghai Biochip Co., Ltd) included qualifiers representing open reading frame (ORF) sequences identified in the genomes of the S. epidermidis strain RP62A, as well as unique ORFs in S. epidermidis strain 12228. The GeneChips were composed of cDNA array containing PCR products of 2316 genes and oligonucleotide array containing 252 genes.Two-component regulatory systems (TCSs) play a pivotal role in bacterial adaptation, survival, and virulence by sensing changes in the external environment and modulating gene expression in response to a variety of stimuli.To investigate the regulatory role of LytSR, one of the TCSs identified in the genomes of S. epidermidis, we used the GeneChips to perform a transcriptional profile analysis of the wild strain and lytSR mutant.
Project description:Autoinducer 2 (AI-2), a widespread by-product of the LuxS-catalyzed S-ribosylhomocysteine cleavage reaction in the activated methyl cycle, has been suggested to serve as an intra- and interspecies signaling molecule, but in many bacteria AI-2 control of gene expression is not completely understood. Particularly, we have a lack of knowledge about AI-2 signaling in the important human pathogens Staphylococcus aureus and S. epidermidis. Here, to determine the role of LuxS and AI-2 in S. epidermidis, we analyzed genome-wide changes in gene expression in an S. epidermidis luxS mutant and after addition of AI-2 synthesized by over-expressed S. epidermidis Pfs and LuxS enzymes. Genes under AI-2 control included mostly genes involved in sugar, nucleotide, amino acid, and nitrogen metabolism, but also virulence-associated genes coding for lipase and bacterial apoptosis proteins. In addition, we demonstrate by liquid chromatography/mass-spectrometry of culture filtrates that the pro-inflammatory phenol-soluble modulin (PSM) peptides, key virulence factors of S. epidermidis, are under luxS/AI-2 control. Our results provide a detailed molecular basis for the role of LuxS in S. epidermidis virulence and suggest a signaling function for AI-2 in this bacterium. Keywords: wild type without glucose control vs luxS mutant vs luxS mutant with auto-inducer II
Project description:The custom-made S. epidermidis GeneChips(Shanghai Biochip Co., Ltd) included qualifiers representing open reading frame (ORF) sequences identified in the genomes of the S. epidermidis strain RP62A, as well as unique ORFs in S. epidermidis strain 12228. The GeneChips were composed of cDNA array containing PCR products of 2316 genes and oligonucleotide array containing 252 genes.Two-component regulatory systems (TCSs) play a pivotal role in bacterial adaptation, survival, and virulence by sensing changes in the external environment and modulating gene expression in response to a variety of stimuli.To investigate the regulatory role of LytSR, one of the TCSs identified in the genomes of S. epidermidis, we used the GeneChips to perform a transcriptional profile analysis of the wild strain and lytSR mutant. Wild type untreated in triplicate is compared to lytSR mutant in triplicate for cDNA array and four replicates on the oligo array.
Project description:Autoinducer 2 (AI-2), a widespread by-product of the LuxS-catalyzed S-ribosylhomocysteine cleavage reaction in the activated methyl cycle, has been suggested to serve as an intra- and interspecies signaling molecule, but in many bacteria AI-2 control of gene expression is not completely understood. Particularly, we have a lack of knowledge about AI-2 signaling in the important human pathogens Staphylococcus aureus and S. epidermidis. Here, to determine the role of LuxS and AI-2 in S. epidermidis, we analyzed genome-wide changes in gene expression in an S. epidermidis luxS mutant and after addition of AI-2 synthesized by over-expressed S. epidermidis Pfs and LuxS enzymes. Genes under AI-2 control included mostly genes involved in sugar, nucleotide, amino acid, and nitrogen metabolism, but also virulence-associated genes coding for lipase and bacterial apoptosis proteins. In addition, we demonstrate by liquid chromatography/mass-spectrometry of culture filtrates that the pro-inflammatory phenol-soluble modulin (PSM) peptides, key virulence factors of S. epidermidis, are under luxS/AI-2 control. Our results provide a detailed molecular basis for the role of LuxS in S. epidermidis virulence and suggest a signaling function for AI-2 in this bacterium. Keywords: wild type without glucose control vs luxS mutant vs luxS mutant with auto-inducer II wild type without glucose control vs luxS mutant vs luxS mutant with auto-inducer II
Project description:In clinical settings, the intensive use of antibiotics, particularly in intensive care settings, leads to a significant increase in the number of bacterial species that are resistant to treatment. In this context, biofilm is a crucial virulence factor that enable bacteria to persist within the host, often resulting in the need for extensive antibiotic treatment. Staphylococcus epidermidis, a notable nosocomial pathogen, poses a risk to vulnerable patients due to its ability to form biofilms on indwelling medical devices and its high resistance to antibiotic therapy. For this purpose, investigating alternative strategies that target the virulence of pathogens could offer a promising alternative strategy. In this study, we analyzed innovative polymeric materials, such as polysaccharide-based nanohydrogels, for their potential application contrasting S. epidermidis monospecies biofilm on the surfaces of materials most employed in medical devices. These nanohydrogels were found to be effective in eradicating the biofilm matrix and preventing bacterial adhesion. Additionally, the treatment with hyaluronan-based nanohydrogels altered the surface protein profile of S. epidermidis, leading to the disappearance of AtlE, the primary autolysin involved in biofilm formation, suggesting a potential mechanism of action for these nanogels.