Project description:In situ microbial community succession on mild steel in estuarine and marine environments – SSU rRNA gene data from single amplified genomes
Project description:The objective was to identify functional genes encoded by Fungi and fungal-like organisms to assess putative ecological roles Using the GeoChip microarray, we detected fungal genes involved in the complete assimilation of nitrate and the degradation of lignin, as well as evidence for Partitiviridae (a mycovirus) that likely regulates fungal populations in the marine environment. These results demonstrate the potential for fungi to degrade terrigenously-sourced molecules, such as permafrost and compete with algae for nitrate during blooms. Ultimately, these data suggest that marine fungi could be as important in oceanic ecosystems as they are in freshwater environments.
Project description:We utilized host-pathogen dual RNA-sequencing to elucidate the transcriptomes of both Chlamydia trachomatis and the infected HeLa cell during nutritional conditions that induce persistence.
Project description:Variations between strains have been extensively studied in human pathogens mainly because even genomically highly identical strains can cause severely different phenotypes in their hosts. Here we investigate within-species diversity in Rhabdochlamydia porcellionis a pathogen infecting terrestrial isopods and a member of the phylum Chlamydia that also includes well-known human pathogens as Chlamydia trachomatis. Using an infection assay in Sf9 insect cell cultures we could show that albeit there are only few genomic variations, the strains 15C and ZGO cause different phenotypes. To investigate potential underlying mechanisms we carried out a global gene expression analysis and could show that changes in major metabolic pathways help strain 15C to replicate more efficiently in the host cells. In addition we found that genes shown to be involved in pathogenicity and host interaction of human pathogenic chlamydia i.e. genes encoding the type III secretion system and polymorphic membrane proteins are regulated differently by the strains.
Project description:Genital C. trachomatis (CT) infection may cause pelvic inflammatory disease (PID) that can lead to tubal factor infertility (TFI). Understanding the pathogenesis of chlamydial complications including the pathophysiological processes within the female host genital tract is of immense importance in preventing adverse pathology. In this study, we tested the hypothesis that the miRNA profile of a acute primary chlamydial infection characterized by temporary inflammation versus the profile associated with chronic genital chlamydial infections that might precipitate PID or TFI will be different. Thus, we analyzed and compared the differentially expressed miRNAs that regulate CT pathogenesis after a single genital infection and those involved in the development of PID and TFI after repeat infections. Mice (Mus musculus) were infected with Chlamydia muridarum once or twice with a month interval between infections, and then sacrificed and genital tract tissues were collected at 1, 2, 4, and 8 weeks after infection. miRNAs were differentially expressed in both first infection and the re-infection; however, the miRNA expression profile was different for both groups. Pathway analysis showed that, amongst other functions, the differentially regulated miRNA might be regulating several pathways involved in cellular and tissue development, disease conditions and toxicity. Grant number: 1SC2HD086066-03 Funding source: Eunice Kennedy Shriver National Institute of Child Health & Human Development Title: Discovering Novel Biomarkers Predictive of Tubal Infertility Caused by Chlamydia. Principal investigator: Yusuf Omosun Date: 05/01/2015-04/30/2019
Project description:Chlamydia trachomatis is a significant human pathogen yet their obligate intracellular nature severe restrictions upon research. Chlamydiae undergo a complex developmental cycle characterized by an infectious cell type known as the elementary body (EB) and an intracellular active replicative form called the reticulate body (RB). EBs have historically been described as metabolically dormant. A cell-free (axenic) culture system was developed which showed high levels of metabolic and biosynthetic activity from both EBs and RBs. EBs preferentially utilized glucose-6-phosphate as an energy source whereas RBs required ATP. Both developmental forms showed improved activity when incubated under microaerobic conditions. Incorporation of isotopically-labeled amino acids into proteins from both developmental forms indicated unique expression profiles which were confirmed by genome-wide transcriptional analysis. The described axenic culture system will greatly enhance biochemical and physiological analyses of chlamydiae. Chlamydia axenic metabolic activity