GTDB Taxonomy
One-Sentence Definition
The Genome Taxonomy Database (GTDB) is a standardized, genome-based bacterial and archaeal taxonomy that redefines ranks using phylogeny and relative evolutionary divergence, implemented operationally via GTDB-Tk.
Simple Explanation
GTDB rebuilds the bacterial family tree from genomes (not just 16S) and gives every genome a consistent name path — even when old Bergey names disagree.
Detailed Scientific Explanation
- Places genomes on a reference tree using marker genes.
- Normalizes ranks so “genus” and “family” mean comparable divergence.
- Often splits or renames traditional taxa (important for environmental and clinical edge cases).
- GTDB-Tk classifies user assemblies; outputs include closest reference and ANI-like support.
Complements but does not replace clinical naming conventions overnight — reports may need dual labels (clinical name vs GTDB).
Mechanism
Identify bac120/ar53 marker set → place in reference tree → assign taxonomy string → optional de novo relative divergence checks.
Clinical Importance
- Clarifies cryptic species complexes after WGS.
- Improves microbiome and One Health studies feeding into clinical risk maps.
Research Importance
- Default taxonomy for modern microbial genomics and MAG catalogs (Metagenome-Assembled Genomes).
Diagnostic Relevance
- Used when ANI and Species Delineation and MALDI conflict; not yet the primary bedside naming system.
AMR Relevance
Consistent species labels improve AMR surveillance aggregation across labs and countries (FAIR Data and Genomic Surveillance).
Related Methods
Related MOCs
Active Recall Questions
- What tool classifies genomes against GTDB?
- Why might GTDB names differ from textbook names?
- How does GTDB relate to ANI?