Bacteroides fragilis is an obligately anaerobic, non-spore-forming Gram-negative rod in the family Bacteroidaceae, and the most clinically significant species within the genus. Despite being a minority member of the normal colonic microbiota, it is the anaerobe most frequently isolated from intra-abdominal abscesses, peritonitis, and bloodstream infections, with its polysaccharide capsule being a key virulence determinant that promotes abscess formation. B. fragilis has a genome of approximately 5.2 Mb with extensive phase-variable surface polysaccharide loci and, in enterotoxigenic strains, encodes the metalloprotease fragilysin (BFT), which has been linked to inflammatory diarrhoea and colorectal neoplasia.
Derived from 1,329 genomes: 36 from RefSeq and 1,293 from other sources. For the derivation pipeline and the PASS / WARN / FAIL verdict model, see the methods page for qualibact-v1.0.
This table summarises the distribution of each metric, including standard deviation, mean, median, and percentiles.
A combined summary table across all species is available on the summary page.
| Metric | Distribution | n | Mean | SD | Min | Q1 | Median | Q3 | Max |
|---|---|---|---|---|---|---|---|---|---|
| N50 | non-normal | 1,293 | 291,692 | 184,000 | 18,597 | 163,432 | 243,165 | 387,349 | 1,030,783 |
| no_of_contigs | non-normal | 1,293 | 111.11 | 75.44 | 22 | 64 | 89 | 138 | 626 |
| longest | non-normal | 1,293 | 668,090 | 341,879 | 63,593 | 441,467 | 593,384 | 837,712 | 2,518,889 |
| GC_Content | non-normal | 1,293 | 43.35 | 0.17 | 42.95 | 43.26 | 43.31 | 43.46 | 44.05 |
| Completeness_Specific | non-normal | 1,293 | 99.97 | 0.08 | 98.17 | 99.97 | 99.98 | 99.99 | 100 |
| Contamination | non-normal | 1,293 | 1.16 | 1.1 | 0.01 | 0.4 | 0.64 | 1.8 | 9.36 |
| Total_Coding_Sequences | non-normal | 1,293 | 4,439 | 175.87 | 3,969 | 4,364 | 4,416 | 4,533 | 5,527 |
| Genome_Size | non-normal | 1,293 | 5,243,530 | 146,553 | 4,828,794 | 5,174,981 | 5,231,414 | 5,314,591 | 6,076,614 |
Full statistics including KS test vs RefSeq and Wasserstein distance are in the downloadable summary.csv.
Derived from 1,329 genomes including 36 RefSeq references
Both Fail and Warn bands shown as the published rounded values — easier to cite and consistent across the species page, CSV downloads, and downstream QC tools.
| Metric | Fail below | Warn below | Warn above | Fail above |
|---|---|---|---|---|
| Genome_Size | - | - | - | - |
| GC_Content | - | - | - | - |
| Total_Coding_Sequences | - | - | - | - |
| Completeness_Specific | - | - | - | - |
| Contamination | - | - | - | - |
| N50 | - | - | - | - |
| no_of_contigs | - | - | - | - |
| longest | - | - | - | - |
How to read this: A value outside a failure limit fails QC. Within the failure limits, values beyond a warning limit are borderline and worth a manual look; values within the warning limits pass that criterion. A dash means that no bound is defined on that side.