Table 2.
Classification of T6SSs. T6SSi−ii and T6SSiii−iv belong to Gram-negative bacteria of taxonomically distinct subgroups.
| Organism | Phylum | Class | T6SS Category |
|---|---|---|---|
| Vibrio cholerae | Gammaproteobacteria | Gammaproteobacteria | T6SSi |
| Pseudomonas aeruginosa | Gammaproteobacteria | Gammaproteobacteria | T6SSi |
| Francisella tularensis | Gammaproteobacteria | Gammaproteobacteria | T6SSii |
| Bacteroides fragilis | Bacteroidetes | Bacteroidetes | T6SSiii |
| Flavobacterium johnsoniae | Bacteroidetes | Flavobacteriia | T6SSiii |
| Ca. Amoebophilus asiaticus | Bacteroidetes | Cytophagis | T6SSiv |