Project description:Skin commensal bacteria (Staphylococcus epidermidis) can help defend against skin infections, and they are increasingly being recognized for their role in benefiting skin health. This study aims to demonstrate the activities that Myristica fragrans Houtt. seed extracts, crude extract (CE) and essential oil (EO), have in terms of promoting the growth of the skin commensal bacterium S. epidermidis and providing metabolites under culture conditions to disrupt the biofilm formation of the common pathogen Staphylococcus aureus.
Project description:We integrated genomic and transcriptomic analysis of a newly isolated obligate Methylomonas sp. DH-1 grown on methane and methanol. Comparative transcriptomic analysis between methane and methanol as a sole carbon source revealed different transcriptional responses of Methylomonas sp. DH-1, especially in C1 assimilation, the secondary metabolites pathways and the oxidative stress related genes
Project description:Cholera is a deadly diarrheal disease that affects millions of people globally. Although V. cholerae, the causative agent of the disease, has been extensively studied in isolation, it was relatively recently that scientists started investigating its interactions with the gut microbiota. Our group and others previously showed that microbiota-derived metabolites significantly influence V. cholerae behavior. By investigating how an organic extract of human feces affects V. cholerae gene expression, we recently showed that gut metabolites strongly suppress swimming motility, a virulence factor important for host colonization. Interestingly, extracts of pure cultures of a single gut commensal, Enterocloster citroniae, recapitulated this inhibitory effect. Here, we present a comprehensive examination of the effect of small molecules produced by E. citroniae and related species on V. cholerae behavior. We show that E. citroniae small molecules inhibit motility by various V. cholerae strains. We also show that several phylogenetically related species produce this activity, although the magnitude of the effect varies between strains. Using biofilm formation assays in static and shear flow conditions, we show that V. cholerae strongly induces biofilm formation in response to E. citroniae metabolites. Transcriptome and reporter analyses show that several genes involved in the synthesis of an extracellular polysaccharide are induced by growth in the presence of E. citroniae metabolites. Lastly, we show that V. cholerae interactions with host epithelial cells are also modulated by compounds produced by this commensal. These findings advance our understanding of microbiome-pathogen interactions and how commensal bacteria influence V. cholerae virulence through the production of small molecules. In the future, this knowledge may be used to design novel microbiome-based therapeutic approaches to combat cholera and other infections.
Project description:Although the bacterium Symbiobacterium thermophilum has a genome with a high guanine-cytosine (GC) content (69%), it belongs to a low GC content bacterial group. We detected only 18 low GC content regions with 5 or more consecutive genes whose GC contents were below 65% in the genome of this organism. S. thermophilum has 66 transposase genes, which are markers of transposable genetic elements, and 38 (58%) of them were located in the low GC content regions, suggesting that Symbiobacterium has a similar gene silencing system as Salmonella. The top hit (best match) analyses for each Symbiobacterium protein showed that putative horizontally transferred genes and vertically inherited genes are scattered across the genome. Approximately 25% of the 3338 Symbiobacterium proteins have the highest similarity with the protein of a phylogenetically distant organism. The putative horizontally transferred genes also have a high GC content, suggesting that Symbiobacterium has gained many DNA fragments from phylogenetically distant organisms during the early stage of Firmicutes evolution. After acquiring genes, Symbiobacterium increased the GC content of the horizontally transferred genes and thereby maintained a genome with a high GC content.
