Project description:Full reciprocal transfer of microbiomes between nine host strains of phytoplankton and microbe-free controls (Kuijpers et al unpublished). Microbiomes were naturally recruited from lake and stream water in an assembly experiment (Broe et al unpublished). Transferred microbiomes were added to axenic hosts and grown for 7 or 14 days before control or heat shock treatment.
Project description:The clinical importance of microbiomes to the chronicity of wounds is widely appreciated, yet little is understood about patient-specific processes shaping wound microbiome composition. Here, a two-cohort microbiome-genome wide association study is presented through which patient genomic loci associated with chronic wound microbiome diversity were identified. Further investigation revealed that alternative TLN2 and ZNF521 genotypes explained significant inter-patient variation in relative abundance of two key pathogens, Pseudomonas aeruginosa and Staphylococcus epidermidis. Wound diversity was lowest in Pseudomonas aeruginosa infected wounds, and decreasing wound diversity had a significant negative linear relationship with healing rate. In addition to microbiome characteristics, age, diabetic status, and genetic ancestry all significantly influenced healing. Using structural equation modeling to identify common variance among SNPs, six loci were sufficient to explain 53% of variation in wound microbiome diversity, which was a 10% increase over traditional multiple regression. Focusing on TLN2, genotype at rs8031916 explained expression differences of alternative transcripts that differ in inclusion of important focal adhesion binding domains. Such differences are hypothesized to relate to wound microbiomes and healing through effects on bacterial exploitation of focal adhesions and/or cellular migration. Related, other associated loci were functionally enriched, often with roles in cytoskeletal dynamics. This study, being the first to identify patient genetic determinants for wound microbiomes and healing, implicates genetic variation determining cellular adhesion phenotypes as important drivers of infection type. The identification of predictive biomarkers for chronic wound microbiomes may serve as risk factors and guide treatment by informing patient-specific tendencies of infection.
Project description:<p>Marine sponges can host abundant and diverse microbiomes, which can largely influence the metabolism and other phenotypic traits of the host. However, information on the potential relationships between sponge microbiomes and metabolic signatures, other than secondary metabolites explored for biotechnological purposes, needs further investigation. Applying an integrated approach, we investigated the microbiomes associated with 4 ubiquitous Mediterranean sponge species (i.e., Petrosia ficiformis, Chondrosia reniformis, Crambe crambe and Chondrilla nucula), correlated with their metabolomic patterns (in terms of lipidomics) and microbial predicted functions. Microscopy observations of sponge tissues revealed differences in microbial abundances, which, however, were only partially linked to their diversity assessed through metabarcoding. The microbiomes of the 4 sponges showed a species-specific composition and a different core size, which was independent from the microbial diversity of the surrounding seawater. Predicted functions of the associated microbiomes allowed identifying 2 functional host clusters: one more related to heterotrophic pathways and the other more linked to phototrophic activities. Differences in the microbiomes were also associated with different metabolic profiles, mostly due to specific compounds characterizing the host and its microbiome. Overall, this study provides new insights on the functionality of sponges and their prokaryotic symbioses’, and in particular, it discloses a descriptive sketch of the diverse compartments forming the sponge holobiont.</p>
Project description:Although gut microbiomes are generally symbiotic or commensal, some of microbiomes become pathogenic under certain circumstances, which is one of key processes of pathogenesis. However, the factors involved in these complex gut-microbe interactions are largely unknown. Here we show that bacterial nucleoside catabolism using gut luminal uridine is required to boost inter-bacterial communications and gut pathogenesis in Drosophila. We found that uridine-derived uracil is required for DUOX-dependent ROS generation on the host side, whereas uridine-derived ribose induces quorum sensing and virulence gene expression on the bacterial side. Importantly, genetic ablation of bacterial nucleoside catabolism is sufficient to block the commensal-to-pathogen transition in vivo. Furthermore, we found that major commensal bacteria lack functional nucleoside catabolism, which is required to achieve gut-microbe symbiosis. The discovery of a novel role of bacterial nucleoside catabolism will greatly help to better understand the molecular mechanism of the commensal-to-pathogen transition in different contexts of host-microbe interactions.
2020-04-07 | GSE140194 | GEO
Project description:Parasite microbiomes and host manipulation