Project description:We report the transcriptional profiles from individual Drosophila melanogaster (whole bodies or dissected brains) to Entomophthora muscae at 24 time points following fungal exposure. In whole fruit fly bodies, a significant immune response is observed following exposure to the fungus. In brains, few differences are consistently observed between infected and uninfected animals.
Project description:Ionophores are antibacterial compounds that affect bacterial growth by changing intracellular concentrations of the essential cations, sodium and potassium. They are extensively used in animal husbandry to increase productivity and reduce infectious diseases. Given their widespread usage, it is important to determine the potential negative consequences of ionophore use on human and animal health. In this study, we demonstrate that exposure to the ionophore monensin can select for resistant mutants in the human and animal pathogen Staphylococcus aureus, with a majority of the resistant mutants showing increased growth rates in vitro and/or in mice. Whole-genome sequencing and proteomics analysis of the resistant mutants show that the resistance phenotype is associated with de-repression of de novo purine synthesis, which could be achieved through mutations in different transcriptional regulators including mutations in the gene purR, the repressor of the purine de novo synthesis pathway. This study shows that mutants with reduced susceptibility to the ionophore monensin can be readily selected and highlights an unexplored link between ionophore resistance, purine metabolism and fitness in pathogenic bacteria.
Project description:Genomes and transcriptomes of non-model organisms can be analyzed using next-generation sequencing technologies, but de-novo sequencing and annotating a full eukaryotic genome is still challenging. So, -omics experimentation with non-model organisms requires a suite of technologies to obtain reliable results in a cost-effective manner. Here, a novel method for microarray-based genome analysis is presented which is especially suitable for non-model organisms. We show that it is useful for complementing regular aCGH analyses and for evaluating transcriptome next-generation sequencing reads. The principle of the method is straightforward: feature intensities obtained after hybridizing the test genome are compared with the feature intensities of a control hybridization. The control hybridization is performed with negative control probes (no targets in the control sample), and with positive control probes (with targets in the control sample). The method has in principle a resolution of a single probe and it does not depend on the structural information of a reference genome: the genomic ordering of probe targets is irrelevant. In a test, analyzing the genome content of a sequenced bacterial strain: Staphylococcus aureus MRSA252, this approach proved to be successful demonstrated by receiver operating characteristic area under the curve values larger than 0.9995. DNA from eleven Staphylococcus aureus strains was extracted in three replicates, fragmented, and hybridized onto the S. aureus multistrain microarray. DNA from MRSA252 was used as common reference, but this channel was omitted in further analyses.
Project description:Young adult fer-15;fem-1 Caenorhabditis elegans were infected with Staphylococcus aureus for 8 h to determine the transcriptional host response to Staphylococcus aureus. Analysis of differential gene expression in C. elegans young adults exposed to two different bacteria: E. coli strain OP50 (control), wild-type Staphylococcus aureus RN6390. Samples were analyzed at 8 hours after exposure to the different bacteria. These studies identified C. elegans genes induced by pathogen infection. Keywords: response to pathogen infection, innate immunity, host-pathogen interactions
Project description:ArlRS is a two-component regulatory system in Staphylococcus aureus. Here we use RNA-sequencing to compare gene expression in a wild-type USA300 strain and an isogenic arlRS mutant.
