Project description:Six bacterial genomes, Geobacter metallireducens GS-15, Chromohalobacter salexigens, Vibrio breoganii 1C-10, Bacillus cereus ATCC 10987, Campylobacter jejuni subsp. jejuni 81-176 and Campylobacter jejuni NCTC 11168, all of which had previously been sequenced using other platforms were re-sequenced using single-molecule, real-time (SMRT) sequencing specifically to analyze their methylomes. In every case a number of new N6-methyladenine (m6A) and N4-methylcytosine (m4C) methylation patterns were discovered and the DNA methyltransferases (MTases) responsible for those methylation patterns were assigned. In 15 cases it was possible to match MTase genes with MTase recognition sequences without further sub-cloning. Two Type I restriction systems required sub-cloning to differentiate their recognition sequences, while four MTases genes that were not expressed in the native organism were sub-cloned to test for viability and recognition sequences. No attempt was made to detect 5-methylcytosine (m5C) recognition motifs from the SMRT sequencing data because this modification produces weaker signals using current methods. However, all predicted m6A and m4C MTases were detected unambiguously. This study shows that the addition of SMRT sequencing to traditional sequencing approaches gives a wealth of useful functional information about a genome showing not only which MTase genes are active, but also revealing their recognition sequences. Examination of the methylomes of six different strains of bacteria using kinetic data from single-molecule, real-time (SMRT) sequencing on the PacBio RS.
Project description:The Enterobacteriaceae are a scientifically and medically important clade of bacteria, containing the gut commensal and model organism Escherichia coli, as well as several major human pathogens including Salmonella enterica and Klebsiella pneumoniae. Essential gene sets have been determined for several members of the Enterobacteriaceae, and the E. coli Keio single-gene deletion library is often regarded as a gold standard for gene essentiality studies. However, it remains unclear how much essential genes vary between strains and species. To investigate this, we have assembled a collection of thirteen sequenced high-density transposon mutant libraries from five genera of the Enterobacteriaceae. We first benchmark a number of gene essentiality prediction approaches, investigate the effects of transposon density on essentiality prediction, and identify biases in transposon insertion sequencing data. Based on these investigations we develop a new classifier for gene essentiality. Using gene essentiality defined by this new classifier, we define a core essential genome in the Enterobacteriaceae of 201 universally essential genes, and reconstruct an ancestral essential gene set of 296 genes. Despite the presence of a large cohort of variably essential genes, we find an absence of evidence for genus-specific essential genes. A clear example of this sporadic essentiality is given by the set of genes regulating the σE extracytoplasmic stress response, which appears to have independently become essential multiple times in the Enterobacteriaceae. Finally, we compare our essential gene sets to the natural experiment of gene loss in obligate insect endosymbionts closely related to the Enterobacteriaceae. This isolates a remarkably small set of genes absolutely required for survival, and uncovers several instances of essential stress responses masked by redundancy in free-living bacteria.
Project description:Chickens are remarkably versatile animals that are used as model organisms for biomedical research. Here, we performed metabolomic analyses of the liver tissue and serum of poultry with different genetic backgrounds, providing detailed information for liver tissue and serum at the metabolite level. The metabolomic data obtained for poultry of different genetic backgrounds will be a valuable resource for further studies on this model organism.
Project description:Study generating and describing the faecal metagenomes of 194 persons occupationally exposed to antimicrobial resistance in livestock (including 46 control subjects).
Highlights:
- DNA of faecal samples of 194 persons occupationally exposed to antimicrobial resistance (AMR) in livestock, i.e. persons living or working on pig and poultry farms and pig slaughterhouse workers and control subjects, was sequenced and metagenomically analysed.
- The faecal resistomes and microbiomes of farmers and slaughterhouse workers were described and compared between occupationally exposed groups and controls.
- We found an increased ARG carriage in persons working in the Dutch pork production chain as compared to poultry farmers and controls.
- Significant differences were found in the resistome and bacteriome composition of pig and pork exposed workers compared to a control group, as well as within-population (farms, slaughterhouse) compositional differences.
- On-farm working hours and working or living on a pig farm (versus poultry farm) are determinants for the human faecal resistome.
- Direct or indirect contact with AMR in livestock may be a determinant for human ARG carriage.
| EGAS00001003944 | EGA
Project description:Enterobacteriaceae from food-producing animals and poultry