R. gnavus
Classification
Bacteria (Domain); Firmicutes (Phylum); Clostridia (Class); Clostridiales (Order); Lachnospiraceae (Family); Mediterraneibacter (Genus)
Species
Description and SignificanceRuminococcus gnavus is a Gram-positive obligate anaerobe bacterium discovered first in the human gastrointestinal tract. Despite its name it is actually a part of the genus Mediterraneibacter, although retaining its Ruminococcus name for study purposes. R. gnavus is considered a part of the normal human gut microbiome in children and adults. It has been suggested that it has a role in priming the gut microbiota in association with standard weight gain velocity in infants. Ruminococcus gnavus is one of few micorbiota bacterium that persists at a consistent level from infancy to throughout adulthood. Studies have shown that R.gnavus is a key biomarker of health and diseases with certain immune/metabolic properties, making it an important bacterium to understand. Genome StructureDescribe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence? R.gnavus was found to have a mean genome size of 3.46±0.34 Mbp, with a mean G+C conctent of 42.73±0.33 mol%. R.gnavus' pan-core genome analysis revealed a predicted 28,072 genes, with the core genes making up 3.74% (1051) of that. The function of the majority of its core genes are not known. Cell Structure, Metabolism and Life CycleInteresting features of cell structure; how it gains energy; what important molecules it produces. Ecology and PathogenesisHabitat; symbiosis; biogeochemical significance; contributions to environment. There are a multitude of studies that show a large positive association between Crohn's disease and Ruminococcus gnavus populations. R. gnavus populations skyrocket during flare ups in Crohn's disease patients. R. gnavus produces an inflammatory glucorhamnan polysaccharide that triggers the production of inflammatory cytokines. Patients experiencing Crohn's disease and an increase in R. gnavus experience symptoms such as abdominal pain, diarrhea, and bloody stool. Patients experiencing extreme symptoms may face inflammation of the eyes, skin, and spine. ReferencesAbdugheni, R., Liu, C., Liu, F.-L., Zhou, N., Jiang, C.-Y., Liu, Y., Li, L., Li, W.-J., & Liu, S.-J. (2023, July 24). Comparative genomics reveals extensive intra-species genetic divergence of the prevalent gut commensal Ruminococcus Gnavus. microbiologyresearch.org. https://www.microbiologyresearch.org/content/journal/mgen/10.1099/mgen.0.001071 Crost, E. H., Coletto, E., Bell, A., & Juge, N. (2023). Ruminococcus gnavus: Friend or foe for human health. FEMS Microbiology Reviews, 47(2). https://doi.org/10.1093/femsre/fuad014 Henke, M. T., Kenny, D. J., Cassilly, C. D., Vlamakis, H., Xavier, R. J., & Clardy, J. (2019, June 25). ruminococcus gnavus, a member of the human gut microbiome associated with crohn’s disease, produces an inflammatory polysaccharide. Proceedings of the National Academy of Sciences of the United States of America. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6601261/ AuthorPage authored by Chris Blackwell, student of Prof. Bradley Tolar at UNC Wilmington. |