Project description:Distal gut bacteria play a pivotal role in the digestion of dietary polysaccharides by producing a large number of carbohydrate-active enzymes (CAZymes) that the host otherwise does not produce. We report here the design of a high density custom microarray that we used to spot non-redundant DNA probes for more than 6,500 genes encoding glycoside hydrolases and lyases selected from 174 reference genomes from distal gut bacteria. The custom microarray was tested and validated by the hybridization of bacterial DNA extracted from the stool samples of lean, obese and anorexic individuals. Our results suggest that a microarray-based study can detect genes from low-abundance bacteria better than metagenomic-based studies. A striking example was the finding that a gene encoding a GH6-family cellulase was present in all subjects examined, whereas metagenomic studies have consistently failed to detect this gene in both human and animal gut microbiomes. In addition, an examination of eight stool samples allowed the identification of a corresponding CAZome core containing 46 families of glycoside hydrolases and polysaccharide lyases, which suggests the functional stability of the gut microbiota despite large taxonomical variations between individuals.
2013-10-28 | GSE51760 | GEO
Project description:PacBio sequencing of 10 host-associated marine bacteria genomes
| PRJNA485019 | ENA
Project description:Complete genomes of bois-noir associated bacteria sequencing and assembly
| PRJNA830658 | ENA
Project description:Metagenome-assembled genomes of the bacteria associated with Ostreobium cultures
Project description:Increasing evidence highlights the role of bacteria in the physiopathology of cancer. However, the underlying molecular mechanisms remains poorly understood. Several cancer-associated bacteria have been shown to produce toxins which modulate the tumor suppressor p53 and thereby interfere with the host defense against tumorigenesis. Here, we show that lipopolysaccharides from Klebsiella pneumoniae (Kp) strongly inhibit the host p53 pathway and impairs p53 transcriptional activity upon DNA damage and oncogenic stress, preventing its tumor suppressive function.
Project description:Next-gen sequencing has facilitated studies of bacterial genomes and uncovered pathogen variants associated with clinically relevant phenotypes such as antibiotic resistance. However, these studies are primarily focused on bacteria cultured from patient tissues, and thus, viable but non-cultivable bacteria are not assessed. This yields an incomplete genetic state of bacteria during infection. Nevertheless, it is possible to capture bacterial transcripts in libraries designed to amplify eukaryotic mRNA. These reads are often considered spurious or nuisance and are rarely investigated. Here we demonstrate that Mycobacterium tuberculosis (Mtb) ribosomal RNA sequences are detected in host human cells obtained from peripheral lymph node aspirates from patients infected with Mtb.