TABLE 3.
Regulation of genes required for virulence in humans by either (p)ppGpp or DksA
| Gene(s)a | Function | 35000HPΔrelAΔspoT/35000HPb,c | 35000HPΔdksA/35000HPb,d |
|---|---|---|---|
| Fully attenuated | |||
| flp-1–flp-2–flp-3 | Adherence and microcolony formation | −3.72 | −2.33e |
| tadA | Adherence and microcolony formation | −6.86 | – |
| dsrA | Major role in serum resistance | – | – |
| lspA1, lspA2 | Escape from phagocytosis | −2.75, −5.36f | −2.57f |
| ncaA | Collagen binding | – | – |
| hgbA | Heme and/or iron uptake | −2.54 | −2.37 |
| pal | Outer membrane stability | – | – |
| hfq | RNA binding chaperone | 11.67 | 2.64 |
| sapB-sapC | Resistance to antimicrobial peptides | – | – |
| cpxA | Two-component sensor kinase | – | – |
| Partially attenuated | |||
| dltA | Partial role in serum resistance | – | 4.98 |
| wecA | Initiates synthesis of putative glycoconjugate | – | – |
| luxS | Quorum sensing | – | – |
| fgbA | Fibrinogen binding | 2.04 | – |
| sapA | Resistance to antimicrobial peptides | – | – |
| csrA | Posttranscriptional regulation | −2.34 | – |
| dksA | DnaK repressor; (p)ppGpp cofactor | – | NA |
| relA, spoT | (p)ppGpp synthetase and hydrolase; stringent response | NA | 2.09 (spoT) |
a
Strains with mutated genes that have been tested in human volunteers and classified as fully or partially attenuated.
b
Fold change of the first differentially regulated gene in the operon. –, no change in expression; NA, not applicable.
c
Fold change in 35000HPΔrelAΔspoT mutant relative to 35000HP strain in stationary phase.
d
Fold change in 35000HPΔdksA mutant relative to 35000HP strain in stationary phase.
e
Fold change of flp-3 only.
f
Fold change of the lspB-lspA2 operon.