TABLE 1.
Virulence factors encoded by chromosomal Shigella PAIs
| PAI | Gene(s) | Biochemical activity | Virulence function(s) | Reference(s) |
|---|---|---|---|---|
| SHI-1 | sigA | Immunoglobulin A-like cytopathic protease | Intestinal fluid accumulation, cytopathic toxin | 5 |
| pic | Serine protease, mucinase | Mucus permeabilization, serum resistance, hemagglutination | 105 | |
| set1A, set1B | Enterotoxin ShET1 | Intestinal fluid accumulation, development of watery diarrhea | 70, 71 | |
| SHI-2 | iucA to iucD, iutA | Siderophore (aerobactin) production and transport | Iron acquisition | 177, 182, 322 |
| shiD | Unknown | Colicin I and colicin V immunity | ||
| shiA | Unknown | Downregulation of inflammation by suppression of T-cell signaling | 116, 117 | |
| SHI-3 | iucA to iucD, iutA | Aerobactin production and transport | Iron acquisition (found only in S. boydii) | 227 |
| SHI-O | gtrA, gtrB, gtrV | Modification of O antigens, serotype conversion | Evasion of host immune response | 113, 115 |
| SRL | fecA to fecE, fecI, fecR | Ferric dicitrate uptake | Iron acquisition | 154, 314 |
| tetA to tetD, tetR | Efflux system | Tetracycline resistance | ||
| cat | Acetyltransferase | Chloramphenicol resistance | ||
| oxa-1 | β-Lactamase | Ampicillin resistance | ||
| aadA1 | Adenylyltransferase | Streptomycin resistance |